Re: [bolger] Re: Fiddler 3 construction and foam insulation
For meaty bulkhead attachment and selective reinforcement all over the hull, I'd still favor a ply/epoxy/glass hull that is structurally fine by itself and then add the structural detailing and then apply inside or outside the foam/ply lamination.
Incidentally in regards to hull-panel shaping, on the 39'x7'6" SACPAS-3 project (#681) I favored and executed the full-length - i.e. 39'+ - topsides shaping for curve and twist, including application of first two coats of paint. Once stored in a rack on the legs of the two gantries that lifted and moved these 275lbs panels, they were thus ready to be 'hung' once the bottom was done to the same level of completion and turned over. This just left the seam along the chine-log joint. Ergo, profile- rocker, section-flare and planview-curves were 'locked-in' during the two ply-layer plus glass and paint assembly. And no challenge scaling up or down. But always a no-drip epoxy- and then paint-surface.
Back to the Narrowboat - while his light-weight Narrowboat visuals do imitate the heavy steel/iron ancestors above-waterline, his bottom-plate and box keel shapes are not what he calls hydrodynamic, at best tolerable at modest canal-speeds - for which these are designed. Due to the unavoidable eddies along the forward edge of a perfectly flat/no-rocker 'chine', reaching towards full hull-speed would not be a happy affair without a big rudder, extra power and an alert helmsman; eddies at the bow make for lively steering. Chine- and Box keel-Rocker would spoil the inch-deep 'authenticity' of the blunt-bowed and rounded burdensome ancestors - but would make a significant difference going up big European rivers.
So,
- thumbs-up on the materials experiment and practical track-record,
Susanne Altenburger, PB&F
P.S.: I would assume that 'Cousin Pee' will attempt to show him as well the error of his ways by sharing his naked-&-wet refrigerator-foam anecdote with him...
----- Original Message -----
From:Tim JenningsSent:Sunday, December 23, 2012 2:49 PMSubject:Re: [bolger] Re: Fiddler 3 construction and foam insulationFor the last year I've been corresponding with Edmund Sylvester, a UK boat builder and designer, who has built several large boats (18 to 50 ft canal cruisers) with a technique he's perfected using composite panels. The panels are made up of 2 sheets of 1/4" plywood skins glued to either side of a 1" sheet of DOW blueboard styrofoam. It's a bit more complicated than it sounds: he makes a 4'x8' frame of 1"x1" clear pine battens around the perimiter of one sheet of ply, with 2 additional battens spaced across the middle of the ply, inserts foam panels to fit the 3 cavities formed by the batten frame, slathers the whole affair between layers with liberal amounts of polyurethane glue (aka Gorrilla Glue), lays on the top sheet of ply, then presses the assembly together in a home built vacuum bag press, usually overnight. The resulting panel is extremely stiff, strong, and lightweight. Edmund's designs attempt to use these flat panels for as much of the hull as possible. The panels cannot be bent to a curve unless they are layed up and vacuum bagged on a form to the desired curvature ahead of time. Constant camber decks, cabin tops, and transoms can thus be accommodated. Bows and quarters are built conventionally. The panels are joined by butting the 1.5 inch thick ends together with resin, then fiberglass taped on either side along the joint (he cuts 3 inch wide mortises about 1/16th inch deep along the seam of the panels to be joined to accept the thickness of the glass tape. Completed hulls are then glassed with resin and faired conventionally.I've given only the barest of info here on the technique. You need to visit his web site for more detailed information. I'm certain that his proven home built composite panel techniques would find use for, in not hulls, lightweight superstructure assemblies, bulkheads, decks, and for non marine applications such as camper shells. He has a number of boats banging around European canals for several years now, testament to the durability of his panels.Tim JenningsEnfield, NHAs implied, on the 'cored boat hull & deck' issue a broad spectrum of sources of particular failures apply, with 'forensics' likely ranging from case to case. And then there are the hulls without those failures...
WEST-folks suggest roughing up the shiny surface of DOW blue foam-board.
On the foam-compression the assumption seems to be a 'naked' piece ?! We 'tested'crudely one such 1/8" ply x 2" foam x 1/8" ply x 10oz glass-cloth measuring 1'x8'. None of this is 'scientific' but certainly interesting:
- 1. Over 4"x4" blocking supporting just the ends and with the glass-cloth facing down we gingerly loaded up the piece via weights to beyond 550lbs as it just bent to touch the shop-floor.
- 2. We backed one corner of a 5500lbs vehicle over the piece supported just on its rear-end with the 4x4 upon which it first bent until the wheel got near the 4x4 and the top unglassed 1/8" ply failed by compression sliding over itself, with the separation within the foam just below the epoxy-line.
- 3. Laying flat on the concrete shop-floor we used the blunt face of a 5lbs hammer on the glassed surface and leaving a mild impression it bounced violently off.
- 4. For better control and less injury-potential we used a 10lbs sledge-hammer and it cut into the glassed surface - but by just 1/8"-1/4" and could not perforate the sandwich. Then we had at it 'something fierce' and 'made holes' - but not easily and predictably either.
We never took this beyond a basic curiosity as to how 'useless' such a sandwich would be... and it seemed to do better than we had assumed.
Surely no good reason to gamble a whole hull-structure on this. But the question here and elsewhere was posed under the assumption of having an adequate hull-structure before adding to it on the outside.
As to 'leaning with your shoulder...' the sledge-hammer exercise resolves that concern.
Installation of external foam over a sharpie-hull or multi-chine hull would be way easier if you add another chine-log and (de facto) sheer-clamp to finish the thickness of the proposed foam-addition. Then apply the foam, the lighter ply-skin and finally the glass - 'and Bob's your Uncle...' (or something)...
And as to blocking her up, there is the 'hard' keel and the hard chinelog - as before.
Plus of course enlarging each stanchion head-pad if one insisted on the 'softer' locations.
And coming alongside both chinelog and sheer-clamp will 'take the hit' - plus of course the rubrail itself.
As to 'picking poison', it is instructive to see the apparent durability of massive wooden laminations working on land and more importantly in the water on hulls from dinks and cold-molded trailer-types over 'Mega-Yachts' to 1000-1400+ tons naval vessels. Certainly, some of them go 'south' sooner than others in certain parts of their structures, likely similar in their 'forensics' to how 'soft' production solid and cored fiberglass-hulls can get, next to rusting steel and corroding aluminum hulls across all sizes and purposes.
Short of raising doubt about any and all aspects of cold/('hot')-molded wooden hulls which are painted, varnished, epoxied, glassed or epoxied, glassed, and then painted multiple layers - it would seem that we have a reasonable sense of both empirical understanding of 'the stuff' - which invariably invites exploring options to push matters further, such as via the original question posed about foam over hull on FIDDLER III.
Susanne Altenburger, PB&F----- Original Message -----From:GregorySent:Monday, December 17, 2012 11:12 AMSubject:[bolger] Re: Fiddler 3 construction and foam insulationCored boat hulls and decks get wet all the time, even when built to highest possible standard. TPI invented SCRIMP infusion and we've all seen plenty or Jboats, Freedoms, and other high-end, "scientifically" constructed cores fail. Of course, epoxy accepts water slower than vinylester, which accepts water slower than polyester, and many failures can be attributed to improperly made penetrations, or just, penetrations. In nature, all voids are temporary.
And, I own a cored boat and built a cored airplane.
Dow Blue may not rot, but its glue lines will likely fail (right along its slick surface). Wood rot happens quickest within a narrow range between totally dry and soaking wet, but trapping water in a "closed" wood system is a bad idea. It's at the core of the argument to encapsulate the interior or let it dry. Pick your poison.
Balsa will rot, but it offers mechanical strength. Balsa is used end-grain; meaning the fibers "T" against the skins, with a compressive strength of about 2000 psi.
http://www.gurit.cn/Files/Documents/Wind%20Energy%20Datasheets%20%28English%29/Balsaflex_WE_v3.pdf
Dow Formular High Compressive Strength Rigid Foam Insulation has a compression strength of about 25-40 psi. Their failure criteria is interesting:
"Compressive resistance at yield or 10 %
"deformation, whichever occurs fi rst (with skins 40psi
"intact) min, psi (kPa)
http://commercial.owenscorning.com/products/foam/foamular-400/
http://commercial.owenscorning.com/assets/0/144/172/174/c18a63f8-2e4e-447b-97f3-3c8436223a20.pdf
So, if your survived rot and shear failure, imagine what's going to happen when you sling your boat out, block it with stands, set it on trailer bunks, bump against a piling, or even lean your shoulder against it in the boatyard. At least outer skin will stop at the inner skin.
Seems like a lot of work to avoid insulating the interior ;-)
Gregg
http://www.yachtsurvey.com/core_materials.htm
--- Inbolger@yahoogroups.com, <philbolger@...> wrote:
>
> Regular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
>
> Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
>
> And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
>
> Susanne Altenburger, PB&F
> ----- Original Message -----
> From: Gregory
> To:bolger@yahoogroups.com
> Sent: Sunday, December 16, 2012 2:46 PM
> Subject: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
> I don't like it, but it's more of a material complaint.
>
> It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
>
> The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
> Duflex.)
>
>http://www.duflex.com.au/duflex2/products/strips
>
> Still, unless you build a significant set of structural skins, your core will get wet.
>
> Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
>
>http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
>
> All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
>
> Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
>
> Gregg
>
> --- Inbolger@yahoogroups.com, "daschultz8275@" <daschultz8275@> wrote:
> >
> > So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
> >
> > I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
> >
> > Whatcha' think?
> >
>
--Tim Jennings
Director of FacilitiesCardigan Mountain School
62 Alumni Drive
Canaan, NH 03741
Phone: (603)523-3536
Cell: (603)443-0279
Fax: (603)523-3550
Home: (603)632-
Email: tjennings@...
WWW:http://www.cardigan.org
On Mon, Dec 17, 2012 at 1:45 PM,<philbolger@...>wrote:As implied, on the 'cored boat hull & deck' issue a broad spectrum of sources of particular failures apply, with 'forensics' likely ranging from case to case. And then there are the hulls without those failures...
WEST-folks suggest roughing up the shiny surface of DOW blue foam-board.
On the foam-compression the assumption seems to be a 'naked' piece ?! We 'tested'crudely one such 1/8" ply x 2" foam x 1/8" ply x 10oz glass-cloth measuring 1'x8'. None of this is 'scientific' but certainly interesting:
- 1. Over 4"x4" blocking supporting just the ends and with the glass-cloth facing down we gingerly loaded up the piece via weights to beyond 550lbs as it just bent to touch the shop-floor.
- 2. We backed one corner of a 5500lbs vehicle over the piece supported just on its rear-end with the 4x4 upon which it first bent until the wheel got near the 4x4 and the top unglassed 1/8" ply failed by compression sliding over itself, with the separation within the foam just below the epoxy-line.
- 3. Laying flat on the concrete shop-floor we used the blunt face of a 5lbs hammer on the glassed surface and leaving a mild impression it bounced violently off.
- 4. For better control and less injury-potential we used a 10lbs sledge-hammer and it cut into the glassed surface - but by just 1/8"-1/4" and could not perforate the sandwich. Then we had at it 'something fierce' and 'made holes' - but not easily and predictably either.
We never took this beyond a basic curiosity as to how 'useless' such a sandwich would be... and it seemed to do better than we had assumed.
Surely no good reason to gamble a whole hull-structure on this. But the question here and elsewhere was posed under the assumption of having an adequate hull-structure before adding to it on the outside.
As to 'leaning with your shoulder...' the sledge-hammer exercise resolves that concern.
Installation of external foam over a sharpie-hull or multi-chine hull would be way easier if you add another chine-log and (de facto) sheer-clamp to finish the thickness of the proposed foam-addition. Then apply the foam, the lighter ply-skin and finally the glass - 'and Bob's your Uncle...' (or something)...
And as to blocking her up, there is the 'hard' keel and the hard chinelog - as before.
Plus of course enlarging each stanchion head-pad if one insisted on the 'softer' locations.
And coming alongside both chinelog and sheer-clamp will 'take the hit' - plus of course the rubrail itself.
As to 'picking poison', it is instructive to see the apparent durability of massive wooden laminations working on land and more importantly in the water on hulls from dinks and cold-molded trailer-types over 'Mega-Yachts' to 1000-1400+ tons naval vessels. Certainly, some of them go 'south' sooner than others in certain parts of their structures, likely similar in their 'forensics' to how 'soft' production solid and cored fiberglass-hulls can get, next to rusting steel and corroding aluminum hulls across all sizes and purposes.
Short of raising doubt about any and all aspects of cold/('hot')-molded wooden hulls which are painted, varnished, epoxied, glassed or epoxied, glassed, and then painted multiple layers - it would seem that we have a reasonable sense of both empirical understanding of 'the stuff' - which invariably invites exploring options to push matters further, such as via the original question posed about foam over hull on FIDDLER III.
Susanne Altenburger, PB&F----- Original Message -----From:GregorySent:Monday, December 17, 2012 11:12 AMSubject:[bolger] Re: Fiddler 3 construction and foam insulationCored boat hulls and decks get wet all the time, even when built to highest possible standard. TPI invented SCRIMP infusion and we've all seen plenty or Jboats, Freedoms, and other high-end, "scientifically" constructed cores fail. Of course, epoxy accepts water slower than vinylester, which accepts water slower than polyester, and many failures can be attributed to improperly made penetrations, or just, penetrations. In nature, all voids are temporary.
And, I own a cored boat and built a cored airplane.
Dow Blue may not rot, but its glue lines will likely fail (right along its slick surface). Wood rot happens quickest within a narrow range between totally dry and soaking wet, but trapping water in a "closed" wood system is a bad idea. It's at the core of the argument to encapsulate the interior or let it dry. Pick your poison.
Balsa will rot, but it offers mechanical strength. Balsa is used end-grain; meaning the fibers "T" against the skins, with a compressive strength of about 2000 psi.
http://www.gurit.cn/Files/Documents/Wind%20Energy%20Datasheets%20%28English%29/Balsaflex_WE_v3.pdf
Dow Formular High Compressive Strength Rigid Foam Insulation has a compression strength of about 25-40 psi. Their failure criteria is interesting:
"Compressive resistance at yield or 10 %
"deformation, whichever occurs fi rst (with skins 40psi
"intact) min, psi (kPa)
http://commercial.owenscorning.com/products/foam/foamular-400/
http://commercial.owenscorning.com/assets/0/144/172/174/c18a63f8-2e4e-447b-97f3-3c8436223a20.pdf
So, if your survived rot and shear failure, imagine what's going to happen when you sling your boat out, block it with stands, set it on trailer bunks, bump against a piling, or even lean your shoulder against it in the boatyard. At least outer skin will stop at the inner skin.
Seems like a lot of work to avoid insulating the interior ;-)
Gregg
http://www.yachtsurvey.com/core_materials.htm
--- Inbolger@yahoogroups.com, <philbolger@...> wrote:
>
> Regular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
>
> Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
>
> And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
>
> Susanne Altenburger, PB&F
> ----- Original Message -----
> From: Gregory
> To:bolger@yahoogroups.com
> Sent: Sunday, December 16, 2012 2:46 PM
> Subject: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
> I don't like it, but it's more of a material complaint.
>
> It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
>
> The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
> Duflex.)
>
>http://www.duflex.com.au/duflex2/products/strips
>
> Still, unless you build a significant set of structural skins, your core will get wet.
>
> Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
>
>http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
>
> All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
>
> Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
>
> Gregg
>
> --- Inbolger@yahoogroups.com, "daschultz8275@" <daschultz8275@> wrote:
> >
> > So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
> >
> > I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
> >
> > Whatcha' think?
> >
>
--Tim Jennings
Director of FacilitiesCardigan Mountain School
62 Alumni Drive
Canaan, NH 03741
Phone: (603)523-3536
Cell: (603)443-0279
Fax: (603)523-3550
Home: (603)632-
Email:tjennings@...
WWW:http://www.cardigan.org
------------------------------
On Wed, Dec 19, 2012 4:37 PM PSTphilbolger@...wrote:
>I should add that quite similar stuff - if not identical stuff - is used in these parts to float for instance wooden floats. And that blue foam lasted on our own floats for at least three decades, with little water-weight gain - but plenty of mussel weight-gain. Nope no aqua-farming intended.
>At any rate, the blue foam-stuff just won't sink...
>
>Susanne Altenburger, PB&F
>
>
> ----- Original Message -----
> From:philbolger@...
> To:bolger@yahoogroups.com
> Sent: Wednesday, December 19, 2012 7:06 PM
> Subject: Re: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
>
>
> So the millions of homes built with the stuff inside and outside of foundation-walls to insulate basements have all 'been had' then ?
>
> Good thing that we are talking boats and epoxy-&-fiberglass over plywood etc....
>
> And I've been told that freezers just do not go well - not matter the outboard power.
>
> Susanne Altenburger, PB&F
>
> ----- Original Message -----
> From: Tom Pee
> To:bolger@yahoogroups.com
> Sent: Wednesday, December 19, 2012 12:40 PM
> Subject: Re: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
>
> In 2001, took out about 10 years blueboard insulation around a large commercial refridgerator/freezer. It was completely saturated with water and surprisingly it didnt break easily when we tried to reduce sizes to carry away. Pieces of about 2'x2' were about all some men could carry.
>
>
> From: "philbolger@..." <philbolger@...>
> To:bolger@yahoogroups.com
> Sent: Monday, December 17, 2012 1:45 PM
> Subject: Re: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
> As implied, on the 'cored boat hull & deck' issue a broad spectrum of sources of particular failures apply, with 'forensics' likely ranging from case to case. And then there are the hulls without those failures...
>
> WEST-folks suggest roughing up the shiny surface of DOW blue foam-board.
>
> On the foam-compression the assumption seems to be a 'naked' piece ?! We 'tested' crudely one such 1/8" ply x 2" foam x 1/8" ply x 10oz glass-cloth measuring 1'x8'. None of this is 'scientific' but certainly interesting:
> - 1. Over 4"x4" blocking supporting just the ends and with the glass-cloth facing down we gingerly loaded up the piece via weights to beyond 550lbs as it just bent to touch the shop-floor.
> - 2. We backed one corner of a 5500lbs vehicle over the piece supported just on its rear-end with the 4x4 upon which it first bent until the wheel got near the 4x4 and the top unglassed 1/8" ply failed by compression sliding over itself, with the separation within the foam just below the epoxy-line.
> - 3. Laying flat on the concrete shop-floor we used the blunt face of a 5lbs hammer on the glassed surface and leaving a mild impression it bounced violently off.
> - 4. For better control and less injury-potential we used a 10lbs sledge-hammer and it cut into the glassed surface - but by just 1/8"-1/4" and could not perforate the sandwich. Then we had at it 'something fierce' and 'made holes' - but not easily and predictably either.
>
> We never took this beyond a basic curiosity as to how 'useless' such a sandwich would be... and it seemed to do better than we had assumed.
>
> Surely no good reason to gamble a whole hull-structure on this. But the question here and elsewhere was posed under the assumption of having an adequate hull-structure before adding to it on the outside.
>
> As to 'leaning with your shoulder...' the sledge-hammer exercise resolves that concern.
> Installation of external foam over a sharpie-hull or multi-chine hull would be way easier if you add another chine-log and (de facto) sheer-clamp to finish the thickness of the proposed foam-addition. Then apply the foam, the lighter ply-skin and finally the glass - 'and Bob's your Uncle...' (or something)...
>
> And as to blocking her up, there is the 'hard' keel and the hard chinelog - as before.
> Plus of course enlarging each stanchion head-pad if one insisted on the 'softer' locations.
>
> And coming alongside both chinelog and sheer-clamp will 'take the hit' - plus of course the rubrail itself.
>
> As to 'picking poison', it is instructive to see the apparent durability of massive wooden laminations working on land and more importantly in the water on hulls from dinks and cold-molded trailer-types over 'Mega-Yachts' to 1000-1400+ tons naval vessels. Certainly, some of them go 'south' sooner than others in certain parts of their structures, likely similar in their 'forensics' to how 'soft' production solid and cored fiberglass-hulls can get, next to rusting steel and corroding aluminum hulls across all sizes and purposes.
>
> Short of raising doubt about any and all aspects of cold/('hot')-molded wooden hulls which are painted, varnished, epoxied, glassed or epoxied, glassed, and then painted multiple layers - it would seem that we have a reasonable sense of both empirical understanding of 'the stuff' - which invariably invites exploring options to push matters further, such as via the original question posed about foam over hull on FIDDLER III.
>
> Susanne Altenburger, PB&F
>
>
> ----- Original Message -----
> From: Gregory
> To:bolger@yahoogroups.com
> Sent: Monday, December 17, 2012 11:12 AM
> Subject: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
> Cored boat hulls and decks get wet all the time, even when built to highest possible standard. TPI invented SCRIMP infusion and we've all seen plenty or Jboats, Freedoms, and other high-end, "scientifically" constructed cores fail. Of course, epoxy accepts water slower than vinylester, which accepts water slower than polyester, and many failures can be attributed to improperly made penetrations, or just, penetrations. In nature, all voids are temporary.
>
> And, I own a cored boat and built a cored airplane.
>
> Dow Blue may not rot, but its glue lines will likely fail (right along its slick surface). Wood rot happens quickest within a narrow range between totally dry and soaking wet, but trapping water in a "closed" wood system is a bad idea. It's at the core of the argument to encapsulate the interior or let it dry. Pick your poison.
>
> Balsa will rot, but it offers mechanical strength. Balsa is used end-grain; meaning the fibers "T" against the skins, with a compressive strength of about 2000 psi.
>
>http://www.gurit.cn/Files/Documents/Wind%20Energy%20Datasheets%20%28English%29/Balsaflex_WE_v3.pdf
>
> Dow Formular High Compressive Strength Rigid Foam Insulation has a compression strength of about 25-40 psi. Their failure criteria is interesting:
>
> "Compressive resistance at yield or 10 %
> "deformation, whichever occurs fi rst (with skins 40psi
> "intact) min, psi (kPa)
>
>http://commercial.owenscorning.com/products/foam/foamular-400/
>
>http://commercial.owenscorning.com/assets/0/144/172/174/c18a63f8-2e4e-447b-97f3-3c8436223a20.pdf
>
> So, if your survived rot and shear failure, imagine what's going to happen when you sling your boat out, block it with stands, set it on trailer bunks, bump against a piling, or even lean your shoulder against it in the boatyard. At least outer skin will stop at the inner skin.
>
> Seems like a lot of work to avoid insulating the interior ;-)
>
> Gregg
>
>http://www.yachtsurvey.com/core_materials.htm
>
> --- In mailto:bolger%40yahoogroups.com, <philbolger@...> wrote:
> >
> > Regular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
> >
> > Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
> >
> > And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
> >
> > Susanne Altenburger, PB&F
> > ----- Original Message -----
> > From: Gregory
> > To: mailto:bolger%40yahoogroups.com
> > Sent: Sunday, December 16, 2012 2:46 PM
> > Subject: [bolger] Re: Fiddler 3 construction and foam insulation
> >
> >
> >
> > I don't like it, but it's more of a material complaint.
> >
> > It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
> >
> > The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
> > Duflex.)
> >
> >http://www.duflex.com.au/duflex2/products/strips
> >
> > Still, unless you build a significant set of structural skins, your core will get wet.
> >
> > Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
> >
> >http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
> >
> > All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
> >
> > Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
> >
> > Gregg
> >
> > --- In mailto:bolger%40yahoogroups.com, "daschultz8275@" <daschultz8275@> wrote:
> > >
> > > So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
> > >
> > > I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
> > >
> > > Whatcha' think?
> > >
> >
>
>
>
>
>
At any rate, the blue foam-stuff just won't sink...
Susanne Altenburger, PB&F
----- Original Message -----From:philbolger@...Sent:Wednesday, December 19, 2012 7:06 PMSubject:Re: [bolger] Re: Fiddler 3 construction and foam insulationSo the millions of homes built with the stuff inside and outside of foundation-walls to insulate basements have all 'been had' then ?
Good thing that we are talking boats and epoxy-&-fiberglass over plywood etc....
And I've been told that freezers just do not go well - not matter the outboard power.
Susanne Altenburger, PB&F----- Original Message -----From:Tom PeeSent:Wednesday, December 19, 2012 12:40 PMSubject:Re: [bolger] Re: Fiddler 3 construction and foam insulationIn 2001, took out about 10 years blueboard insulation around a large commercial refridgerator/freezer. It was completely saturated with water and surprisingly it didnt break easily when we tried to reduce sizes to carry away. Pieces of about 2'x2' were about all some men could carry.From:"philbolger@..." <philbolger@...>
To:bolger@yahoogroups.com
Sent:Monday, December 17, 2012 1:45 PM
Subject:Re: [bolger] Re: Fiddler 3 construction and foam insulationAs implied, on the 'cored boat hull & deck' issue a broad spectrum of sources of particular failures apply, with 'forensics' likely ranging from case to case. And then there are the hulls without those failures...
WEST-folks suggest roughing up the shiny surface of DOW blue foam-board.
On the foam-compression the assumption seems to be a 'naked' piece ?! We 'tested'crudely one such 1/8" ply x 2" foam x 1/8" ply x 10oz glass-cloth measuring 1'x8'. None of this is 'scientific' but certainly interesting:
- 1. Over 4"x4" blocking supporting just the ends and with the glass-cloth facing down we gingerly loaded up the piece via weights to beyond 550lbs as it just bent to touch the shop-floor.
- 2. We backed one corner of a 5500lbs vehicle over the piece supported just on its rear-end with the 4x4 upon which it first bent until the wheel got near the 4x4 and the top unglassed 1/8" ply failed by compression sliding over itself, with the separation within the foam just below the epoxy-line.
- 3. Laying flat on the concrete shop-floor we used the blunt face of a 5lbs hammer on the glassed surface and leaving a mild impression it bounced violently off.
- 4. For better control and less injury-potential we used a 10lbs sledge-hammer and it cut into the glassed surface - but by just 1/8"-1/4" and could not perforate the sandwich. Then we had at it 'something fierce' and 'made holes' - but not easily and predictably either.
We never took this beyond a basic curiosity as to how 'useless' such a sandwich would be... and it seemed to do better than we had assumed.
Surely no good reason to gamble a whole hull-structure on this. But the question here and elsewhere was posed under the assumption of having an adequate hull-structure before adding to it on the outside.
As to 'leaning with your shoulder...' the sledge-hammer exercise resolves that concern.
Installation of external foam over a sharpie-hull or multi-chine hull would be way easier if you add another chine-log and (de facto) sheer-clamp to finish the thickness of the proposed foam-addition. Then apply the foam, the lighter ply-skin and finally the glass - 'and Bob's your Uncle...' (or something)...
And as to blocking her up, there is the 'hard' keel and the hard chinelog - as before.
Plus of course enlarging each stanchion head-pad if one insisted on the 'softer' locations.
And coming alongside both chinelog and sheer-clamp will 'take the hit' - plus of course the rubrail itself.
As to 'picking poison', it is instructive to see the apparent durability of massive wooden laminations working on land and more importantly in the water on hulls from dinks and cold-molded trailer-types over 'Mega-Yachts' to 1000-1400+ tons naval vessels. Certainly, some of them go 'south' sooner than others in certain parts of their structures, likely similar in their 'forensics' to how 'soft' production solid and cored fiberglass-hulls can get, next to rusting steel and corroding aluminum hulls across all sizes and purposes.
Short of raising doubt about any and all aspects of cold/('hot')-molded wooden hulls which are painted, varnished, epoxied, glassed or epoxied, glassed, and then painted multiple layers - it would seem that we have a reasonable sense of both empirical understanding of 'the stuff' - which invariably invites exploring options to push matters further, such as via the original question posed about foam over hull on FIDDLER III.
Susanne Altenburger, PB&F----- Original Message -----From:GregorySent:Monday, December 17, 2012 11:12 AMSubject:[bolger] Re: Fiddler 3 construction and foam insulationCored boat hulls and decks get wet all the time, even when built to highest possible standard. TPI invented SCRIMP infusion and we've all seen plenty or Jboats, Freedoms, and other high-end, "scientifically" constructed cores fail. Of course, epoxy accepts water slower than vinylester, which accepts water slower than polyester, and many failures can be attributed to improperly made penetrations, or just, penetrations. In nature, all voids are temporary.
And, I own a cored boat and built a cored airplane.
Dow Blue may not rot, but its glue lines will likely fail (right along its slick surface). Wood rot happens quickest within a narrow range between totally dry and soaking wet, but trapping water in a "closed" wood system is a bad idea. It's at the core of the argument to encapsulate the interior or let it dry. Pick your poison.
Balsa will rot, but it offers mechanical strength. Balsa is used end-grain; meaning the fibers "T" against the skins, with a compressive strength of about 2000 psi.
http://www.gurit.cn/Files/Documents/Wind%20Energy%20Datasheets%20%28English%29/Balsaflex_WE_v3.pdf
Dow Formular High Compressive Strength Rigid Foam Insulation has a compression strength of about 25-40 psi. Their failure criteria is interesting:
"Compressive resistance at yield or 10 %
"deformation, whichever occurs fi rst (with skins 40psi
"intact) min, psi (kPa)
http://commercial.owenscorning.com/products/foam/foamular-400/
http://commercial.owenscorning.com/assets/0/144/172/174/c18a63f8-2e4e-447b-97f3-3c8436223a20.pdf
So, if your survived rot and shear failure, imagine what's going to happen when you sling your boat out, block it with stands, set it on trailer bunks, bump against a piling, or even lean your shoulder against it in the boatyard. At least outer skin will stop at the inner skin.
Seems like a lot of work to avoid insulating the interior ;-)
Gregg
http://www.yachtsurvey.com/core_materials.htm
--- Inmailto:bolger%40yahoogroups.com, <philbolger@...> wrote:
>
> Regular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
>
> Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
>
> And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
>
> Susanne Altenburger, PB&F
> ----- Original Message -----
> From: Gregory
> To:mailto:bolger%40yahoogroups.com
> Sent: Sunday, December 16, 2012 2:46 PM
> Subject: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
> I don't like it, but it's more of a material complaint.
>
> It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
>
> The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
> Duflex.)
>
>http://www.duflex.com.au/duflex2/products/strips
>
> Still, unless you build a significant set of structural skins, your core will get wet.
>
> Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
>
>http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
>
> All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
>
> Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
>
> Gregg
>
> --- Inmailto:bolger%40yahoogroups.com, "daschultz8275@" <daschultz8275@> wrote:
> >
> > So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
> >
> > I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
> >
> > Whatcha' think?
> >
>
Good thing that we are talking boats and epoxy-&-fiberglass over plywood etc....
And I've been told that freezers just do not go well - not matter the outboard power.
Susanne Altenburger, PB&F
----- Original Message -----From:Tom PeeSent:Wednesday, December 19, 2012 12:40 PMSubject:Re: [bolger] Re: Fiddler 3 construction and foam insulationIn 2001, took out about 10 years blueboard insulation around a large commercial refridgerator/freezer. It was completely saturated with water and surprisingly it didnt break easily when we tried to reduce sizes to carry away. Pieces of about 2'x2' were about all some men could carry.From:"philbolger@..." <philbolger@...>
To:bolger@yahoogroups.com
Sent:Monday, December 17, 2012 1:45 PM
Subject:Re: [bolger] Re: Fiddler 3 construction and foam insulationAs implied, on the 'cored boat hull & deck' issue a broad spectrum of sources of particular failures apply, with 'forensics' likely ranging from case to case. And then there are the hulls without those failures...
WEST-folks suggest roughing up the shiny surface of DOW blue foam-board.
On the foam-compression the assumption seems to be a 'naked' piece ?! We 'tested'crudely one such 1/8" ply x 2" foam x 1/8" ply x 10oz glass-cloth measuring 1'x8'. None of this is 'scientific' but certainly interesting:
- 1. Over 4"x4" blocking supporting just the ends and with the glass-cloth facing down we gingerly loaded up the piece via weights to beyond 550lbs as it just bent to touch the shop-floor.
- 2. We backed one corner of a 5500lbs vehicle over the piece supported just on its rear-end with the 4x4 upon which it first bent until the wheel got near the 4x4 and the top unglassed 1/8" ply failed by compression sliding over itself, with the separation within the foam just below the epoxy-line.
- 3. Laying flat on the concrete shop-floor we used the blunt face of a 5lbs hammer on the glassed surface and leaving a mild impression it bounced violently off.
- 4. For better control and less injury-potential we used a 10lbs sledge-hammer and it cut into the glassed surface - but by just 1/8"-1/4" and could not perforate the sandwich. Then we had at it 'something fierce' and 'made holes' - but not easily and predictably either.
We never took this beyond a basic curiosity as to how 'useless' such a sandwich would be... and it seemed to do better than we had assumed.
Surely no good reason to gamble a whole hull-structure on this. But the question here and elsewhere was posed under the assumption of having an adequate hull-structure before adding to it on the outside.
As to 'leaning with your shoulder...' the sledge-hammer exercise resolves that concern.
Installation of external foam over a sharpie-hull or multi-chine hull would be way easier if you add another chine-log and (de facto) sheer-clamp to finish the thickness of the proposed foam-addition. Then apply the foam, the lighter ply-skin and finally the glass - 'and Bob's your Uncle...' (or something)...
And as to blocking her up, there is the 'hard' keel and the hard chinelog - as before.
Plus of course enlarging each stanchion head-pad if one insisted on the 'softer' locations.
And coming alongside both chinelog and sheer-clamp will 'take the hit' - plus of course the rubrail itself.
As to 'picking poison', it is instructive to see the apparent durability of massive wooden laminations working on land and more importantly in the water on hulls from dinks and cold-molded trailer-types over 'Mega-Yachts' to 1000-1400+ tons naval vessels. Certainly, some of them go 'south' sooner than others in certain parts of their structures, likely similar in their 'forensics' to how 'soft' production solid and cored fiberglass-hulls can get, next to rusting steel and corroding aluminum hulls across all sizes and purposes.
Short of raising doubt about any and all aspects of cold/('hot')-molded wooden hulls which are painted, varnished, epoxied, glassed or epoxied, glassed, and then painted multiple layers - it would seem that we have a reasonable sense of both empirical understanding of 'the stuff' - which invariably invites exploring options to push matters further, such as via the original question posed about foam over hull on FIDDLER III.
Susanne Altenburger, PB&F----- Original Message -----From:GregorySent:Monday, December 17, 2012 11:12 AMSubject:[bolger] Re: Fiddler 3 construction and foam insulationCored boat hulls and decks get wet all the time, even when built to highest possible standard. TPI invented SCRIMP infusion and we've all seen plenty or Jboats, Freedoms, and other high-end, "scientifically" constructed cores fail. Of course, epoxy accepts water slower than vinylester, which accepts water slower than polyester, and many failures can be attributed to improperly made penetrations, or just, penetrations. In nature, all voids are temporary.
And, I own a cored boat and built a cored airplane.
Dow Blue may not rot, but its glue lines will likely fail (right along its slick surface). Wood rot happens quickest within a narrow range between totally dry and soaking wet, but trapping water in a "closed" wood system is a bad idea. It's at the core of the argument to encapsulate the interior or let it dry. Pick your poison.
Balsa will rot, but it offers mechanical strength. Balsa is used end-grain; meaning the fibers "T" against the skins, with a compressive strength of about 2000 psi.
http://www.gurit.cn/Files/Documents/Wind%20Energy%20Datasheets%20%28English%29/Balsaflex_WE_v3.pdf
Dow Formular High Compressive Strength Rigid Foam Insulation has a compression strength of about 25-40 psi. Their failure criteria is interesting:
"Compressive resistance at yield or 10 %
"deformation, whichever occurs fi rst (with skins 40psi
"intact) min, psi (kPa)
http://commercial.owenscorning.com/products/foam/foamular-400/
http://commercial.owenscorning.com/assets/0/144/172/174/c18a63f8-2e4e-447b-97f3-3c8436223a20.pdf
So, if your survived rot and shear failure, imagine what's going to happen when you sling your boat out, block it with stands, set it on trailer bunks, bump against a piling, or even lean your shoulder against it in the boatyard. At least outer skin will stop at the inner skin.
Seems like a lot of work to avoid insulating the interior ;-)
Gregg
http://www.yachtsurvey.com/core_materials.htm
--- Inmailto:bolger%40yahoogroups.com, <philbolger@...> wrote:
>
> Regular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
>
> Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
>
> And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
>
> Susanne Altenburger, PB&F
> ----- Original Message -----
> From: Gregory
> To:mailto:bolger%40yahoogroups.com
> Sent: Sunday, December 16, 2012 2:46 PM
> Subject: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
> I don't like it, but it's more of a material complaint.
>
> It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
>
> The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
> Duflex.)
>
>http://www.duflex.com.au/duflex2/products/strips
>
> Still, unless you build a significant set of structural skins, your core will get wet.
>
> Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
>
>http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
>
> All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
>
> Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
>
> Gregg
>
> --- Inmailto:bolger%40yahoogroups.com, "daschultz8275@" <daschultz8275@> wrote:
> >
> > So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
> >
> > I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
> >
> > Whatcha' think?
> >
>
To:bolger@yahoogroups.com
Sent:Monday, December 17, 2012 1:45 PM
Subject:Re: [bolger] Re: Fiddler 3 construction and foam insulation
WEST-folks suggest roughing up the shiny surface of DOW blue foam-board.
On the foam-compression the assumption seems to be a 'naked' piece ?! We 'tested'crudely one such 1/8" ply x 2" foam x 1/8" ply x 10oz glass-cloth measuring 1'x8'. None of this is 'scientific' but certainly interesting:
- 1. Over 4"x4" blocking supporting just the ends and with the glass-cloth facing down we gingerly loaded up the piece via weights to beyond 550lbs as it just bent to touch the shop-floor.
- 2. We backed one corner of a 5500lbs vehicle over the piece supported just on its rear-end with the 4x4 upon which it first bent until the wheel got near the 4x4 and the top unglassed 1/8" ply failed by compression sliding over itself, with the separation within the foam just below the epoxy-line.
- 3. Laying flat on the concrete shop-floor we used the blunt face of a 5lbs hammer on the glassed surface and leaving a mild impression it bounced violently off.
- 4. For better control and less injury-potential we used a 10lbs sledge-hammer and it cut into the glassed surface - but by just 1/8"-1/4" and could not perforate the sandwich. Then we had at it 'something fierce' and 'made holes' - but not easily and predictably either.
We never took this beyond a basic curiosity as to how 'useless' such a sandwich would be... and it seemed to do better than we had assumed.
Surely no good reason to gamble a whole hull-structure on this. But the question here and elsewhere was posed under the assumption of having an adequate hull-structure before adding to it on the outside.
As to 'leaning with your shoulder...' the sledge-hammer exercise resolves that concern.
Installation of external foam over a sharpie-hull or multi-chine hull would be way easier if you add another chine-log and (de facto) sheer-clamp to finish the thickness of the proposed foam-addition. Then apply the foam, the lighter ply-skin and finally the glass - 'and Bob's your Uncle...' (or something)...
And as to blocking her up, there is the 'hard' keel and the hard chinelog - as before.
Plus of course enlarging each stanchion head-pad if one insisted on the 'softer' locations.
And coming alongside both chinelog and sheer-clamp will 'take the hit' - plus of course the rubrail itself.
As to 'picking poison', it is instructive to see the apparent durability of massive wooden laminations working on land and more importantly in the water on hulls from dinks and cold-molded trailer-types over 'Mega-Yachts' to 1000-1400+ tons naval vessels. Certainly, some of them go 'south' sooner than others in certain parts of their structures, likely similar in their 'forensics' to how 'soft' production solid and cored fiberglass-hulls can get, next to rusting steel and corroding aluminum hulls across all sizes and purposes.
Short of raising doubt about any and all aspects of cold/('hot')-molded wooden hulls which are painted, varnished, epoxied, glassed or epoxied, glassed, and then painted multiple layers - it would seem that we have a reasonable sense of both empirical understanding of 'the stuff' - which invariably invites exploring options to push matters further, such as via the original question posed about foam over hull on FIDDLER III.
Susanne Altenburger, PB&F
----- Original Message -----From:GregorySent:Monday, December 17, 2012 11:12 AMSubject:[bolger] Re: Fiddler 3 construction and foam insulationCored boat hulls and decks get wet all the time, even when built to highest possible standard. TPI invented SCRIMP infusion and we've all seen plenty or Jboats, Freedoms, and other high-end, "scientifically" constructed cores fail. Of course, epoxy accepts water slower than vinylester, which accepts water slower than polyester, and many failures can be attributed to improperly made penetrations, or just, penetrations. In nature, all voids are temporary.
And, I own a cored boat and built a cored airplane.
Dow Blue may not rot, but its glue lines will likely fail (right along its slick surface). Wood rot happens quickest within a narrow range between totally dry and soaking wet, but trapping water in a "closed" wood system is a bad idea. It's at the core of the argument to encapsulate the interior or let it dry. Pick your poison.
Balsa will rot, but it offers mechanical strength. Balsa is used end-grain; meaning the fibers "T" against the skins, with a compressive strength of about 2000 psi.
http://www.gurit.cn/Files/Documents/Wind%20Energy%20Datasheets%20%28English%29/Balsaflex_WE_v3.pdf
Dow Formular High Compressive Strength Rigid Foam Insulation has a compression strength of about 25-40 psi. Their failure criteria is interesting:
"Compressive resistance at yield or 10 %
"deformation, whichever occurs fi rst (with skins 40psi
"intact) min, psi (kPa)
http://commercial.owenscorning.com/products/foam/foamular-400/
http://commercial.owenscorning.com/assets/0/144/172/174/c18a63f8-2e4e-447b-97f3-3c8436223a20.pdf
So, if your survived rot and shear failure, imagine what's going to happen when you sling your boat out, block it with stands, set it on trailer bunks, bump against a piling, or even lean your shoulder against it in the boatyard. At least outer skin will stop at the inner skin.
Seems like a lot of work to avoid insulating the interior ;-)
Gregg
http://www.yachtsurvey.com/core_materials.htm
--- Inmailto:bolger%40yahoogroups.com, <philbolger@...> wrote:
>
> Regular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
>
> Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
>
> And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
>
> Susanne Altenburger, PB&F
> ----- Original Message -----
> From: Gregory
> To:mailto:bolger%40yahoogroups.com
> Sent: Sunday, December 16, 2012 2:46 PM
> Subject: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
> I don't like it, but it's more of a material complaint.
>
> It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
>
> The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
> Duflex.)
>
>http://www.duflex.com.au/duflex2/products/strips
>
> Still, unless you build a significant set of structural skins, your core will get wet.
>
> Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
>
>http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
>
> All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
>
> Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
>
> Gregg
>
> --- Inmailto:bolger%40yahoogroups.com, "daschultz8275@" <daschultz8275@> wrote:
> >
> > So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
> >
> > I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
> >
> > Whatcha' think?
> >
>
WEST-folks suggest roughing up the shiny surface of DOW blue foam-board.
On the foam-compression the assumption seems to be a 'naked' piece ?! We 'tested'crudely one such 1/8" ply x 2" foam x 1/8" ply x 10oz glass-cloth measuring 1'x8'. None of this is 'scientific' but certainly interesting:
- 1. Over 4"x4" blocking supporting just the ends and with the glass-cloth facing down we gingerly loaded up the piece via weights to beyond 550lbs as it just bent to touch the shop-floor.
- 2. We backed one corner of a 5500lbs vehicle over the piece supported just on its rear-end with the 4x4 upon which it first bent until the wheel got near the 4x4 and the top unglassed 1/8" ply failed by compression sliding over itself, with the separation within the foam just below the epoxy-line.
- 3. Laying flat on the concrete shop-floor we used the blunt face of a 5lbs hammer on the glassed surface and leaving a mild impression it bounced violently off.
- 4. For better control and less injury-potential we used a 10lbs sledge-hammer and it cut into the glassed surface - but by just 1/8"-1/4" and could not perforate the sandwich. Then we had at it 'something fierce' and 'made holes' - but not easily and predictably either.
We never took this beyond a basic curiosity as to how 'useless' such a sandwich would be... and it seemed to do better than we had assumed.
Surely no good reason to gamble a whole hull-structure on this. But the question here and elsewhere was posed under the assumption of having an adequate hull-structure before adding to it on the outside.
As to 'leaning with your shoulder...' the sledge-hammer exercise resolves that concern.
Installation of external foam over a sharpie-hull or multi-chine hull would be way easier if you add another chine-log and (de facto) sheer-clamp to finish the thickness of the proposed foam-addition. Then apply the foam, the lighter ply-skin and finally the glass - 'and Bob's your Uncle...' (or something)...
And as to blocking her up, there is the 'hard' keel and the hard chinelog - as before.
Plus of course enlarging each stanchion head-pad if one insisted on the 'softer' locations.
And coming alongside both chinelog and sheer-clamp will 'take the hit' - plus of course the rubrail itself.
As to 'picking poison', it is instructive to see the apparent durability of massive wooden laminations working on land and more importantly in the water on hulls from dinks and cold-molded trailer-types over 'Mega-Yachts' to 1000-1400+ tons naval vessels. Certainly, some of them go 'south' sooner than others in certain parts of their structures, likely similar in their 'forensics' to how 'soft' production solid and cored fiberglass-hulls can get, next to rusting steel and corroding aluminum hulls across all sizes and purposes.
Short of raising doubt about any and all aspects of cold/('hot')-molded wooden hulls which are painted, varnished, epoxied, glassed or epoxied, glassed, and then painted multiple layers - it would seem that we have a reasonable sense of both empirical understanding of 'the stuff' - which invariably invites exploring options to push matters further, such as via the original question posed about foam over hull on FIDDLER III.
Susanne Altenburger, PB&F
----- Original Message -----From:GregorySent:Monday, December 17, 2012 11:12 AMSubject:[bolger] Re: Fiddler 3 construction and foam insulationCored boat hulls and decks get wet all the time, even when built to highest possible standard. TPI invented SCRIMP infusion and we've all seen plenty or Jboats, Freedoms, and other high-end, "scientifically" constructed cores fail. Of course, epoxy accepts water slower than vinylester, which accepts water slower than polyester, and many failures can be attributed to improperly made penetrations, or just, penetrations. In nature, all voids are temporary.
And, I own a cored boat and built a cored airplane.
Dow Blue may not rot, but its glue lines will likely fail (right along its slick surface). Wood rot happens quickest within a narrow range between totally dry and soaking wet, but trapping water in a "closed" wood system is a bad idea. It's at the core of the argument to encapsulate the interior or let it dry. Pick your poison.
Balsa will rot, but it offers mechanical strength. Balsa is used end-grain; meaning the fibers "T" against the skins, with a compressive strength of about 2000 psi.
http://www.gurit.cn/Files/Documents/Wind%20Energy%20Datasheets%20%28English%29/Balsaflex_WE_v3.pdf
Dow Formular High Compressive Strength Rigid Foam Insulation has a compression strength of about 25-40 psi. Their failure criteria is interesting:
"Compressive resistance at yield or 10 %
"deformation, whichever occurs fi rst (with skins 40psi
"intact) min, psi (kPa)
http://commercial.owenscorning.com/products/foam/foamular-400/
http://commercial.owenscorning.com/assets/0/144/172/174/c18a63f8-2e4e-447b-97f3-3c8436223a20.pdf
So, if your survived rot and shear failure, imagine what's going to happen when you sling your boat out, block it with stands, set it on trailer bunks, bump against a piling, or even lean your shoulder against it in the boatyard. At least outer skin will stop at the inner skin.
Seems like a lot of work to avoid insulating the interior ;-)
Gregg
http://www.yachtsurvey.com/core_materials.htm
--- Inbolger@yahoogroups.com, <philbolger@...> wrote:
>
> Regular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
>
> Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
>
> And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
>
> Susanne Altenburger, PB&F
> ----- Original Message -----
> From: Gregory
> To:bolger@yahoogroups.com
> Sent: Sunday, December 16, 2012 2:46 PM
> Subject: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
> I don't like it, but it's more of a material complaint.
>
> It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
>
> The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
> Duflex.)
>
>http://www.duflex.com.au/duflex2/products/strips
>
> Still, unless you build a significant set of structural skins, your core will get wet.
>
> Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
>
>http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
>
> All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
>
> Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
>
> Gregg
>
> --- Inbolger@yahoogroups.com, "daschultz8275@" <daschultz8275@> wrote:
> >
> > So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
> >
> > I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
> >
> > Whatcha' think?
> >
>
And, I own a cored boat and built a cored airplane.
Dow Blue may not rot, but its glue lines will likely fail (right along its slick surface). Wood rot happens quickest within a narrow range between totally dry and soaking wet, but trapping water in a "closed" wood system is a bad idea. It's at the core of the argument to encapsulate the interior or let it dry. Pick your poison.
Balsa will rot, but it offers mechanical strength. Balsa is used end-grain; meaning the fibers "T" against the skins, with a compressive strength of about 2000 psi.
http://www.gurit.cn/Files/Documents/Wind%20Energy%20Datasheets%20%28English%29/Balsaflex_WE_v3.pdf
Dow Formular High Compressive Strength Rigid Foam Insulation has a compression strength of about 25-40 psi. Their failure criteria is interesting:
"Compressive resistance at yield or 10 %
"deformation, whichever occurs fi rst (with skins 40psi
"intact) min, psi (kPa)
http://commercial.owenscorning.com/products/foam/foamular-400/
http://commercial.owenscorning.com/assets/0/144/172/174/c18a63f8-2e4e-447b-97f3-3c8436223a20.pdf
So, if your survived rot and shear failure, imagine what's going to happen when you sling your boat out, block it with stands, set it on trailer bunks, bump against a piling, or even lean your shoulder against it in the boatyard. At least outer skin will stop at the inner skin.
Seems like a lot of work to avoid insulating the interior ;-)
Gregg
http://www.yachtsurvey.com/core_materials.htm
--- Inbolger@yahoogroups.com, <philbolger@...> wrote:
>
> Regular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
>
> Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
>
> And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
>
> Susanne Altenburger, PB&F
> ----- Original Message -----
> From: Gregory
> To:bolger@yahoogroups.com
> Sent: Sunday, December 16, 2012 2:46 PM
> Subject: [bolger] Re: Fiddler 3 construction and foam insulation
>
>
>
> I don't like it, but it's more of a material complaint.
>
> It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
>
> The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
> Duflex.)
>
>http://www.duflex.com.au/duflex2/products/strips
>
> Still, unless you build a significant set of structural skins, your core will get wet.
>
> Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
>
>http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
>
> All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
>
> Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
>
> Gregg
>
> --- Inbolger@yahoogroups.com, "daschultz8275@" <daschultz8275@> wrote:
> >
> > So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
> >
> > I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
> >
> > Whatcha' think?
> >
>
----- Original Message -----From:philbolger@...Sent:Sunday, December 16, 2012 3:02 PMSubject:Re: [bolger] Re: Fiddler 3 construction and foam insulationRegular home-center DOW blue-board has very low water absorption-rate if left afloat/wet. As an inside-part of a laminate here, it would remain bone-dry !
Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
Susanne Altenburger, PB&F----- Original Message -----From:GregorySent:Sunday, December 16, 2012 2:46 PMSubject:[bolger] Re: Fiddler 3 construction and foam insulationI don't like it, but it's more of a material complaint.
It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
Duflex.)
http://www.duflex.com.au/duflex2/products/strips
Still, unless you build a significant set of structural skins, your core will get wet.
Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
Gregg
--- Inbolger@yahoogroups.com, "daschultz8275@..." <daschultz8275@...> wrote:
>
> So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
>
> I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
>
> Whatcha' think?
>
Good thing that with a structure solid enough to live without the foam-belt, the outside addition of closed-cell blue foam-boards won't constitute any of the challenges quoted such as 'creep', water-absorption etc. Ergo low-cost upgrade of the hull without serious drawbacks, as long as matters are well-bonded and glassed over.
And any weight added via 1/8" skin in this case plus 'paper-weight' foam, plus glue/epoxy/glass will only add very modest weight on the trailer. In the water however, the hull floats up some as it would have gained more buoyancy than net weight. She could carry extra load before immersing to the same waterline as before...
Susanne Altenburger, PB&F
----- Original Message -----From:GregorySent:Sunday, December 16, 2012 2:46 PMSubject:[bolger] Re: Fiddler 3 construction and foam insulationI don't like it, but it's more of a material complaint.
It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
Duflex.)
http://www.duflex.com.au/duflex2/products/strips
Still, unless you build a significant set of structural skins, your core will get wet.
Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
Gregg
--- Inbolger@yahoogroups.com, "daschultz8275@..." <daschultz8275@...> wrote:
>
> So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
>
> I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
>
> Whatcha' think?
>
It doesn't matter if you build from the inside out, or the outside in - your goal should be light weight skins, both stressed and well bonded. If you build a boat with sufficient (stand-alone) interior skin strength, it doesn't make sense to add adhesive, foam and a heavy second skin - you would be smarter and lighter to insulate the interior.
The floatation is the same. (The argument to be able to fair the exterior skin is ~OK, but there are a lot, lot better methods - like
Duflex.)
http://www.duflex.com.au/duflex2/products/strips
Still, unless you build a significant set of structural skins, your core will get wet.
Of course, there are lots of cored boats (and planes), but none with styrofoam. Have a look at Jamestowns cores:
http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Core%20Materials%20and%20Foam&category=399&refine=1&page=GRID
All those foams and balsa have mechanical strengths 2-3 orders of magnitude better than styrofoam - which essentially has none. Your skins will move, and they do, your foam will fail in shear. You'll likely have a boat sitting in a bucket. But, those materials are expensive. Long and short of it, don't use non-structural (weak) materials in a structural sandwich.
Having said that, I similar idea about building a dinghy from extruded styrfoam, where you might waterjet the panels and shape the edges for a nice joint. But, My idea was to cut holes every 6" or foot and insert a transverse wooden dowel, balsa, or some rigid element to transfer shear across skins. You might estimate the period knowing the properties from testing, but still, I think the skins would delaminate eventually. I wouldn't risk it on a big project.
Gregg
--- Inbolger@yahoogroups.com, "daschultz8275@..." <daschultz8275@...> wrote:
>
> So now I am thinking to head back toward Bolger's construction scheme for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom timbers cutaway over the walking area not under the berth. The width of the box keel would be to match the fore/aft keelsons that form the cabinetry.
>
> I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
>
> Whatcha' think?
>
But airplanes typically do not need rubrails, collide with flotsam, skiffs, rub any area of their topsides along floats and piers etc.
So either a lot of glass...
...Or as proposed earlier, thin ply over foam applied to the basic plywood hull. For rot-resistance a fully epoxied (if not glassed) hull, then glue on the foam with foam-compatible LIQUID NAILS etc. (to save on epoxy-cost), tacked-down with drywall-screws and fender-washers if not a batten or two in either direction for decent mating of surfaces. 1" foam board for greater curves x how many layers you'd want. But coat inside of final ply-skin with epoxy before bonding with last layer of foam. Then glass. And tend to screw-holes from both sides as far as possible, with the inside of the ply-hull likely more accessible for a shot from the syringe to reseal the structure.
Result is a major boost towards- if not deeper into on positive buoyancy, plus no more condensation soaking your bedding and stuff in cold waters/cold spell.
Susanne Altenburger, PB&F
----- Original Message -----From:Bob JohnsonSent:Sunday, December 16, 2012 12:32 PMSubject:[bolger] Re: Fiddler 3 construction and foam insulationThere was a guy who built some boats using a similar technique,
described in pretty good detail in the magazine Boatbuilder (used to be
published out of Florida, I think it is gone now). The builder called
it "quick and purty" construction. He would glue foam on the outside
of a ply boat, then sculpt the foam into a nice rounded hull shape, and
sheath it in glass and epoxy.
Bob
> __________________________________________________________
> _
> 1a. Re: Fiddler 3 construction and foam insulation
> Posted by: "daschultz8275@..."
>daschultz8275@...daschultz8275@...
> Date: Sat Dec 15, 2012 11:03 am ((PST))
>
> So now I am thinking to head back toward Bolger's construction scheme
> for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom
> timbers cutaway over the walking area not under the berth. The width
> of the box keel would be to match the fore/aft keelsons that form the
> cabinetry.
>
> I am thinking to clad the OUTSIDE of the hull (not the bottom), on the
> sides and top, with 2" pink foam and wrap that with glass/resin,
> possibly over 1/8" ply for fairing. Anybody tried the foam this way?
> I know PB&F suggested such a scheme for one of the big ASxx cruisers.
> Insulation, floatation, and it gets the water that much farther away
> from the structure.
>
> Whatcha' think?
described in pretty good detail in the magazine Boatbuilder (used to be
published out of Florida, I think it is gone now). The builder called
it "quick and purty" construction. He would glue foam on the outside
of a ply boat, then sculpt the foam into a nice rounded hull shape, and
sheath it in glass and epoxy.
Bob
> _______________________________________________________________________
> _
> 1a. Re: Fiddler 3 construction and foam insulation
> Posted by: "daschultz8275@..."
>daschultz8275@...daschultz8275@...
> Date: Sat Dec 15, 2012 11:03 am ((PST))
>
> So now I am thinking to head back toward Bolger's construction scheme
> for Fiddler 2 and adding the box keel on to it, with the 2x2 bottom
> timbers cutaway over the walking area not under the berth. The width
> of the box keel would be to match the fore/aft keelsons that form the
> cabinetry.
>
> I am thinking to clad the OUTSIDE of the hull (not the bottom), on the
> sides and top, with 2" pink foam and wrap that with glass/resin,
> possibly over 1/8" ply for fairing. Anybody tried the foam this way?
> I know PB&F suggested such a scheme for one of the big ASxx cruisers.
> Insulation, floatation, and it gets the water that much farther away
> from the structure.
>
> Whatcha' think?
I am thinking to clad the OUTSIDE of the hull (not the bottom), on the sides and top, with 2" pink foam and wrap that with glass/resin, possibly over 1/8" ply for fairing. Anybody tried the foam this way? I know PB&F suggested such a scheme for one of the big ASxx cruisers. Insulation, floatation, and it gets the water that much farther away from the structure.
Whatcha' think?
So I've looked up this thread again.
I like my idea to buy MicroTrawler plans, and build a stretched hull, wit a Fiddler II on top of it. Should result in a good camper while on the trailer and a fun "multi-mission" boat with a planing hull that is as well proven as anything Bolger designed.
I've thought to put a popup top on it using modified popup camper hardware. A slot top would be added and the original top could become berths. Probably to much complexity for what it would add.
I'd probably start with an old 2 stroke 40-60 hp motor that would make for a fun lake boat including water ski-ing. I'd go to a 4 stroke 15-20 hp for river camp cruising.
Don
--- Inbolger@yahoogroups.com, "donschultz8275" <donschultz@...> wrote:
>
> --- Inbolger@yahoogroups.com, "Bruce Hallman" <bruce@> wrote:
> >
> > I forget in which book Phil Bolger said he would update Fiddler II,
> > again.
> >
> .......
> Don Schultz wrote.
>
> I was thinking of the box keel just as an add on to the bottom. I
> hadn't thought to use its depth as a walk way. With this change, one
> could build a Microtrawler shaped like a Fiddler II, using
> Microtrawler plans as a guide for scantlings, and building details.
>
>
> Nice renderings Bruce. Imagine the huge increase in comfort and stretch
> out room if she were fitted with a Bridwatched style walk thru cabin. I
> think a simple flip over hardtop would be easiest to build.
> Bruce Hector
>
Any help is welcomed.
Krissie
[Non-text portions of this message have been removed]
Rick
----- Original Message ----
From: dnjost <davidjost@...>
To:bolger@yahoogroups.com
Sent: Sunday, February 24, 2008 9:17:09 AM
Subject: [bolger] Re: Nymph trim
Couldn't the seat be a removeable thwart? thus opening up the entire
boat for sailing. beefing up the gunwales is a really good idea.
David Jost
ps - look for boil test results on Sureply later today.
____________________________________________________________________________________
Never miss a thing. Make Yahoo your home page.
http://www.yahoo.com/r/hs
[Non-text portions of this message have been removed]
boat for sailing. beefing up the gunwales is a really good idea.
David Jost
ps - look for boil test results on Sureply later today.
> ... Does the [Nymph] trim pretty well fore and aft while sittingright behind the [midships] frame, please?
Taking out the seat between the mid and aft frames gives a boat which
trims well for sailing, sitting on the bottom. There's enough seat
left aft for a passenger to perch, and the utility of the adjustable
rowing position is largely [though not entirely] retained. Beefing up
the gunwales to compensate for the loss of backbone is a good idea, I
think.
At the cost of loss of interior volume, it is possible to add buoyancy
bags sufficient to permit the solo sailor re-boarding from a capsize
[using a far from elegant back-flop and roll manoeuvre]. In warm water
it's a lot of fun. The bags I added were stitched up from old
sailcloth and stuffed with pool-noodle.
cheers
Derek
I remember trying to get in my old Nymph from the mother ship. Quite a
site. The tenderness is caused by the hull shape as it is a little
narrow fore and aft along the bottom plank. That said, it rowed very
well in a chop. Once we sat down in it, it rode the swells like a
duck. I actually rowed it back and forth with three grown people in
it. We were obviously all close friends and no modesty was involved
here at all.
You could stop the seat at the midship frame, but would lose some
ability to shift your weight as gear is loaded in and out. Where would
your crew sit? How about a rowing box?
I highly recommend it as a first boat.
David Jost
pics ) by sitting up so high on the straddle seat. That can be left
stopped at the midship frame in order to sit lower down. Does the
boat trim pretty well fore and aft while sitting right behind the
frame, please?
I'm < 200 lbs.
Mark
>
>Yes, I toyed with the idea of a bigger Birdwatcher type slot. But,
>
> Nice renderings Bruce. Imagine the huge increase in comfort and stretch
> out room if she were fitted with a Bridwatched style walk thru cabin. I
> think a simple flip over hardtop would be easiest to build.
> Bruce Hector
based on my experience with my Micro Navigator, which has an extended
slot, I am not sure it would be an improvement. If I were to do my
Micro Navigator over again, I would probably make the roof hatch
smaller. 4'6" of headroom is actually a lot! You can move around
easily, without too much trouble by simply ducking your head. A few
strategically placed hand holds on the ceiling can help tremendously.
Also, I find that, in my Micro, 99.9% of the time I am comfortably
seated (or prone) anyway. Compromises are necessary, and except for
0.1% of the time, I think the improved windage, trailerability, ease
of construction and 'leak control', a solid roof has it's advantages.
Also, for cooking, a Birdwatcher slot isn't the best because while
your head is up, the cook surface and your hands are down (where you
cannot see them that well). Cooking from a seated position is not
hard, I do it all the time in my Micro Navigator, and it is more than
satisfactory.
out room if she were fitted with a Bridwatched style walk thru cabin. I
think a simple flip over hardtop would be easiest to build.
Bruce Hector
>In "30-ODD BOATS" Bolger says he thought to redo Fiddler in 2011.
> I forget in which book Phil Bolger said he would update Fiddler II,
> again.
>
However he determined to finish "more or less" the design at that
time, thus Fiddler has a plan # which I don't remember.
I was thinking of the box keel just as an add on to the bottom. I
hadn't thought to use its depth as a walk way. With this change, one
could build a Microtrawler shaped like a Fiddler II, using
Microtrawler plans as a guide for scantlings, and building details.
Good idea.
> ... a box keel to a Fiddler 2 solves the headroomActually, I think with the box keel she would also handle side winds
> problem, giving 4'6" of headroom, which in my experience is plenty
> comfortable for moving around inside a cabin. While, at the same
> time, keeping the on water windage, and trailer heights pleasantly
> low.
better, even with a low power engine. A small inboard could be fitted
in the box keel ...
Bruce, do you have the estimated minimum operating weight (say only
one boater, minimal supplies)? How deep should the box keel be so that
the waterline just falls very slightly above the top of the box keel?
Means: the wide main cabin would just barely be in the water?
Thanks,
Stefan
> It makes the Fiddler2 more appealing to think about building. I wonder what otherI predict that PCB would also put in a cutwater fillet, like so many
> changes he would make?
of his other recent designs.
http://flickr.com/photos/hallman/2281817417/
I agree that a box keel Fiddler 3 is really appealing. Watervan is
just too big, and adding a box keel to a Fiddler 2 solves the headroom
problem, giving 4'6" of headroom, which in my experience is pleanty
comfortable for moving around inside a cabin. While, at the same
time, keeping the on water windage, and trailer heights pleasantly
low. Also, the SuperBee box keel would probably make a fast runabout,
with the hull rising up and waterskiing nicely.
> Lets see the rule of thumb is 3 to 1 on a barge.The usual temptation ... add here a bit, there a bit ....
> So Fiddler2 is right at 7 feet wide so she could
> be made 21 feet long and not twist the hull in a seaway.
Watervan is 23' x 8' ...
> Now all I need is a place to work!Build her in two or three parts, and scew her together at the launch slip!
First build the curved forward 8 feet as one module, and the aft 4
feet as another one. Screw them together and you are off to go. Later
build the 8 feet middle module and insert it.
Stefan
Fiddler2 more appealing to think about building. I wonder what other
changes he would make? I think for running around my neck of the woods
a bit of deadrise in the sponsons would help keep the pounding down in
the chop we see up here a lot of the summer.
Lets see the rule of thumb is 3 to 1 on a barge. So Fiddler2 is right
at 7 feet wide so she could be made 21 feet long and not twist the
hull in a seaway. Add the 5 feet in the cockpit area and keep the head
in the back... Now all I need is a place to work!
Blessings to all Krissie
--- Inbolger@yahoogroups.com, "Bruce Hallman" <bruce@...> wrote:
>
> I forget in which book Phil Bolger said he would update Fiddler II,
> again. Here are images of what I imagine he would do, that is I
> imagine he would update the hull to have a box keel. This makes her a
> very appealing motor boat cruiser, with 4 1/2 feet of plentyful
> headroom. A snug comfortable cruiser, with a full head and a double
> berth which fits on a small trailer and in 16 foot slip.
>
>http://www.flickr.com/photos/hallman/2274630671/
>
> Here are images of what I imagine he would do, that is IVery nice, indeed.
> imagine he would update the hull to have a box keel. This makes her a
> very appealing motor boat cruiser, with 4 1/2 feet of plentyful
> headroom. A snug comfortable cruiser, with a full head and a double
> berth which fits on a small trailer and in 16 foot slip.
>
>http://www.flickr.com/photos/hallman/2274630671/
That box keel should also make for more comfortable sitting over
longer time.
Would be interesting to know what effects it has on power
requirements, in (semi?) displacement as well as planing mode.
Stefan
again. Here are images of what I imagine he would do, that is I
imagine he would update the hull to have a box keel. This makes her a
very appealing motor boat cruiser, with 4 1/2 feet of plentyful
headroom. A snug comfortable cruiser, with a full head and a double
berth which fits on a small trailer and in 16 foot slip.
http://www.flickr.com/photos/hallman/2274630671/