Re: foam sandwich retrofit question
Chris, by how much does the pink board deform under various loads? How soft or squmbly (tech term) is it? It doesn't have to be as stiff, tough, and etc as plywood. For an instant boat you may need to add some panel curvature by adding some arc to bulkheads or frames, or just make the foam layer thicker. Use less expensive polyester resin and glass for same to lower the cost. Probably overall similar/lower cost than a plywood boat from better stuff. I don't think you'd need any complicated set up for an instant boat (molds, plugs, etc). Cut the foam panels, hot glue tack them together, round angles off and fillet as the spirit moves, apply glass.
Thinks.. asks.. doesn't Dave Gray knock PDRs (family Brickoboatean) out of foam sandwich to good effect?
Another example, not instant though a Bolger: DOLPHIN #259, surf pulling boat for 4 oars, load waterline from 660lb to 1200lb, 17lb lead ballast in the sailing version centreboard, keel, thwarts, breasthooks, knees, posts, hefty bouyancy FOAM SUPPORT to LARGE stern and fore sheets, 21" amidships keel to gunwhale height, 18'x 4' overall, 0.5" strip plank build, ought to weigh what do you think empty? 250 to 300lbs?
What's that? Heavier?
Well then, try only 100lb got out of 3/8" foam sandwich:
http://groups.yahoo.com/group/bolger5/photos/album/837076775/pic/list
http://groups.yahoo.com/group/bolger/message/48541
Thinks.. asks.. doesn't Dave Gray knock PDRs (family Brickoboatean) out of foam sandwich to good effect?
Another example, not instant though a Bolger: DOLPHIN #259, surf pulling boat for 4 oars, load waterline from 660lb to 1200lb, 17lb lead ballast in the sailing version centreboard, keel, thwarts, breasthooks, knees, posts, hefty bouyancy FOAM SUPPORT to LARGE stern and fore sheets, 21" amidships keel to gunwhale height, 18'x 4' overall, 0.5" strip plank build, ought to weigh what do you think empty? 250 to 300lbs?
What's that? Heavier?
Well then, try only 100lb got out of 3/8" foam sandwich:
http://groups.yahoo.com/group/bolger5/photos/album/837076775/pic/list
http://groups.yahoo.com/group/bolger/message/48541
--- Inbolger@yahoogroups.com, "Christopher C. Wetherill" <wetherillc@...> wrote:
>
> All this discussion has brought to mind an old question I have been
> pondering. Has anyone built an Instant Boat from 1/2" pink board with
> fiberglass on both sides? Issues I have been considering
> 1) easier to work than plywood
> 2) slightly less costly than plywood
> 3) not as stiff
> 4) possibly lighter than plywood.
>
> I suspect that the need to glass both sides will result in no savings of
> cost or weight.
>
> Chris
>
I designed and built 3 different hollow windsurfing boards using 1/2" blue foam with an epoxy-glass skin about 15 years ago. Started with internal frames like an airplane wing, then with plank-on frame, then faired with 100 grit sandpaper, and finally a single layer of 4 oz glass and a sanding coat with West 410 microlight filler. They were beautiful, light (12lbs), strong, and fast. I logged hundreds of hours in big conditions on Lake Superior and in the Columbia Gorge.
They were prettier than production boards by Mistral and F2 when new, but they didn't age well. Delamination between the glass skin and blue foam, despite 3 years of experiments to prevent it, resulted in big unsightly bubbles in the skin. Later production sailboards eliminated the deck seams, look as good as my custom designs, and last longer.
My hollow sailboards were not nearly as strong as my Bolger-Payson instant boat construction with 1/4" plywood and a glass skin, but at a fraction of the weight. Because of the potential for gorgeous faired curves with no visible lines between planks, they invite a lot of hours of labor. I considered it time well spent--but that's a lot more work than instant boat construction using plywood.
Thanks for the interesting question, and I sure thought about it a lot--but not so much after I failed to solve the delamination problem. I've never had glass-epoxy cloth delaminate from plywood.
Best Regards,
Rick
They were prettier than production boards by Mistral and F2 when new, but they didn't age well. Delamination between the glass skin and blue foam, despite 3 years of experiments to prevent it, resulted in big unsightly bubbles in the skin. Later production sailboards eliminated the deck seams, look as good as my custom designs, and last longer.
My hollow sailboards were not nearly as strong as my Bolger-Payson instant boat construction with 1/4" plywood and a glass skin, but at a fraction of the weight. Because of the potential for gorgeous faired curves with no visible lines between planks, they invite a lot of hours of labor. I considered it time well spent--but that's a lot more work than instant boat construction using plywood.
Thanks for the interesting question, and I sure thought about it a lot--but not so much after I failed to solve the delamination problem. I've never had glass-epoxy cloth delaminate from plywood.
Best Regards,
Rick
--- Inbolger@yahoogroups.com, "Christopher C. Wetherill" <wetherillc@...> wrote:
>
> All this discussion has brought to mind an old question I have been
> pondering. Has anyone built an Instant Boat from 1/2" pink board with
> fiberglass on both sides? Issues I have been considering
> 1) easier to work than plywood
> 2) slightly less costly than plywood
> 3) not as stiff
> 4) possibly lighter than plywood.
>
> I suspect that the need to glass both sides will result in no savings of
> cost or weight.
>
> Chris
>
> Peter you need approval to join.I'm the moderator, and I can promise approval will be coming within a day. I'll also see about posting elsewhere.
>http://groups.yahoo.com/group/boatdesign/files/Dingbat/
Peter you need approval to join.
In any case, open celled foams can be saturated with water and sink (might take a long time.)
Closed cell foams have gas bubbles that can not be saturated with water, the areas between the gas bubbles can be, but because of the gas bubbles closed celled foams as a rule will not sink and thus make a better choice for flotation.
David
In any case, open celled foams can be saturated with water and sink (might take a long time.)
Closed cell foams have gas bubbles that can not be saturated with water, the areas between the gas bubbles can be, but because of the gas bubbles closed celled foams as a rule will not sink and thus make a better choice for flotation.
David
--- Inbolger@yahoogroups.com, "Peter" <pvanderwaart@...> wrote:
>
> > What you want is one of the Urethane foams, not XPS.
> > XPS is and open cell foam (eXtruded PolyStyrene.)
>
> There was an article long ago in Small Boat Journal about using an expensive foam to build a dinghy. It was an amateur project, and the design is clunky, but it may be instructive. The files are here:
>
>http://groups.yahoo.com/group/boatdesign/files/Dingbat/
>
> I don't think you have to join the group to see them. Joining isn't a problem in any case.
>
> There as a fad for this sort of construction back in the 1970s or thereabouts. It didn't catch on for amateurs. I think the problems of getting a fair surface outweigh any benefits.
>
> If the idea is to build a boat from fiberglass without plywood, another idea is to lay up glass panels on "table." The table would basically be a piece of thick ply with a laminate top, like a big piece of kitchen counter. You can lay up glass to the desired size, and the side next to table will be smooth as glass. Multihull designers Richard Woods and Derek Kelsall have built boats that way.
>
> A problem common to a lot of strong materials is that a panel that is strong enough is not stiff enough. Pure glass panels would require different framing than ply which is stiffer for its strength.
>
> Peter
>
Hi Fred,
The short answer is YES! I use the boat on Lake Superior, been to the Apostles many times. Use it on the St Louis; love Pokegama and Kimball bays. Been to Voyageur's NP From Kab through Namakan into Crane, poking around in nearly all the bays. I did 246 miles in VNP;a place every boater should try to get to as almost all of it is acessible only by boat. No cars! I've been on the St Croix from N of Stillwater at the stopping point down to the Mississippi and S to LaCrosse. Pine Island sound and south into the 10,000 island of the Everglades. Three of the rives in the panhandle around Carrabelle,the St Johns on the E side of Fl, the TX intracoastal from Port Anrasas up to Matagorda. The same area they do the TX 200, but this was Jan and Feb and I some even nastier winds. I wrote about the Fl jaunt, but somehow never got around to writing about the others. That's all on the Bantam, Drifter. Most of my logged mileage is on other boats. This last summer was a write off. Had 12 weeks of Phy T. due to spinal injuries. Read that to mean the damage we all do to ourselfs when young doing things like building boats:)First time since I built my first boat in 1971 I didn't get on the water in one of my own boats. Next summer awaits. Contact me when coming through next summer!
Bob
The short answer is YES! I use the boat on Lake Superior, been to the Apostles many times. Use it on the St Louis; love Pokegama and Kimball bays. Been to Voyageur's NP From Kab through Namakan into Crane, poking around in nearly all the bays. I did 246 miles in VNP;a place every boater should try to get to as almost all of it is acessible only by boat. No cars! I've been on the St Croix from N of Stillwater at the stopping point down to the Mississippi and S to LaCrosse. Pine Island sound and south into the 10,000 island of the Everglades. Three of the rives in the panhandle around Carrabelle,the St Johns on the E side of Fl, the TX intracoastal from Port Anrasas up to Matagorda. The same area they do the TX 200, but this was Jan and Feb and I some even nastier winds. I wrote about the Fl jaunt, but somehow never got around to writing about the others. That's all on the Bantam, Drifter. Most of my logged mileage is on other boats. This last summer was a write off. Had 12 weeks of Phy T. due to spinal injuries. Read that to mean the damage we all do to ourselfs when young doing things like building boats:)First time since I built my first boat in 1971 I didn't get on the water in one of my own boats. Next summer awaits. Contact me when coming through next summer!
Bob
--- Inbolger@yahoogroups.com, Fred Schumacher <fredschum@...> wrote:
>
> On Fri, Dec 31, 2010 at 1:07 PM, otter55806 <otter55806@...> wrote:
>
> >
> >
> > Hey Chester,
> > Glad to read about you and EstherMae! To refresh your memory, you let me
> > park my van and boat trailer at your place while I was off on Drifter, my
> > Bolger Bantam. How I wish I was there now. We had freezing rain here in
> > Duluth last night.
> >
>
> Bob,
>
> Do you use your Bantam on Lake Superior, or in the bay, or any of the lakes
> up north, like Vermilion or Kabetogama? I'm stuck in the Cities now but I'd
> love to see your boat when I head back to the Orr area during summer.
>
> fred s.
>
Good Morning on this first day of 2011. I wish you all a good year.
I would like to thank you for your continuing
interest in Phil's and our work.
I hope that the re-establishment of the monthly
Design-column in MAIB keeps feeding your
curiosity and engagement in our thinking on boats, how to use them, and where to
build them. Note this month's feature on the preliminary design of
"AS-34". Next month will be an update from the world of fisheries-policy
and the working waterfront of Gloucester, essentially a summary of 2 projects of
2010 that I faced myself devoting serious time to, even though I already
had an urgent agenda to tend to both in private matters and business,
primarily of course securing and enhancing the legacy of Phil
Bolger. One motivating factor in the constructive engagement of
these two issues was the further broadening of relative relevance of
Phil Bolger's thinking both on local level and in the discourse
amongst high-level experts.
As Bruce Hallman alerted you to already, Phil Bolger & Friends was invited late February'10 to give a presentation at the first international conference on "Energy Use in Fisheries" in Seattle, Nov. 14-17,'10, sponsored by NOAA (National Oceanographic and Atmospheric Administration) - a branch of the US government, the WORLD BANK and the UN-FAO (U.N. Fisheries and Agriculture Organization). Experts from 18 nations offered perspectives, with me amongst them (quite unexpectedly). MAIB will feature my report on it. It was and remains gratifying indeed to put Phil's and my work into that forum of discussion. That high-level recognition of the fundamental legitimacy of our perspective should contribute to the likelihood of at last getting craft built and tested across 4-seasons.
The other project is directly related to the viability of this Port and its working and pleasure-fleets as we see $4/gal looming on the horizon. When we first raised the issue of accelerating fuel-cost in 2002-03 crude oil was around the low-20s per barrel. Now it has gone past $90 while many of us are still mired in the Great Recession. JP MORGAN speculates about $120 by 2011-12. We've got to be prepared for significantly higher liquid energy-cost in whatever area of life and work we can do something about.
For March MAIB there will be another design feature.
I want to thank the 'keepers' of this Forum and its many steady and casual contributors. In no particular order and addressing you all, I want to thank for instance Bruce Hallman for his efforts to put the 2-D line-art work into more appealing yet visuals, Long for the calender (he sent me one) with beautiful photos not in this archive, Massimo for the stirring video and reports on his IDAHO-project (I linked the YouTube footage to others), and the various authors of key-threads on small and large technical and functional issues along with the many progress-reports and photos on on-going and completed boat-building projects.
During the dark year+ after Phil's death, I did and do draw sustenance from quietly reading your discussions. And I know I should have added to them more than I did. But I am still metering my energies for various daily demands restructuring this existence without my love, mentor, co-conspirator, companion. I constantly miss his presence and find myself often in need of 'the other hand' which is no more. So I draw energy and satisfaction from this Forum, major events (for me) such as Seattle and the knowledge that we did together and now I do try to address issues that seemed to us in need of tending, despite at times fiscal and emotional expenditures not agreed to by our CPA or always supportable by our emotional balance.
There is one more most serious project here in town that depends on this office for success but should also (at last) result in reasonably serious fiscal returns. I'll will report when it is on solid ground.
May this New Year present us all with opportunities and successes, health and balance in our lives, and perhaps a chance to add to the serious and joyful progress in our families and communities.
Susanne Altenburger
As Bruce Hallman alerted you to already, Phil Bolger & Friends was invited late February'10 to give a presentation at the first international conference on "Energy Use in Fisheries" in Seattle, Nov. 14-17,'10, sponsored by NOAA (National Oceanographic and Atmospheric Administration) - a branch of the US government, the WORLD BANK and the UN-FAO (U.N. Fisheries and Agriculture Organization). Experts from 18 nations offered perspectives, with me amongst them (quite unexpectedly). MAIB will feature my report on it. It was and remains gratifying indeed to put Phil's and my work into that forum of discussion. That high-level recognition of the fundamental legitimacy of our perspective should contribute to the likelihood of at last getting craft built and tested across 4-seasons.
The other project is directly related to the viability of this Port and its working and pleasure-fleets as we see $4/gal looming on the horizon. When we first raised the issue of accelerating fuel-cost in 2002-03 crude oil was around the low-20s per barrel. Now it has gone past $90 while many of us are still mired in the Great Recession. JP MORGAN speculates about $120 by 2011-12. We've got to be prepared for significantly higher liquid energy-cost in whatever area of life and work we can do something about.
For March MAIB there will be another design feature.
I want to thank the 'keepers' of this Forum and its many steady and casual contributors. In no particular order and addressing you all, I want to thank for instance Bruce Hallman for his efforts to put the 2-D line-art work into more appealing yet visuals, Long for the calender (he sent me one) with beautiful photos not in this archive, Massimo for the stirring video and reports on his IDAHO-project (I linked the YouTube footage to others), and the various authors of key-threads on small and large technical and functional issues along with the many progress-reports and photos on on-going and completed boat-building projects.
During the dark year+ after Phil's death, I did and do draw sustenance from quietly reading your discussions. And I know I should have added to them more than I did. But I am still metering my energies for various daily demands restructuring this existence without my love, mentor, co-conspirator, companion. I constantly miss his presence and find myself often in need of 'the other hand' which is no more. So I draw energy and satisfaction from this Forum, major events (for me) such as Seattle and the knowledge that we did together and now I do try to address issues that seemed to us in need of tending, despite at times fiscal and emotional expenditures not agreed to by our CPA or always supportable by our emotional balance.
There is one more most serious project here in town that depends on this office for success but should also (at last) result in reasonably serious fiscal returns. I'll will report when it is on solid ground.
May this New Year present us all with opportunities and successes, health and balance in our lives, and perhaps a chance to add to the serious and joyful progress in our families and communities.
Susanne Altenburger
Phil Bolger&Friends, Inc.
> What you want is one of the Urethane foams, not XPS.There was an article long ago in Small Boat Journal about using an expensive foam to build a dinghy. It was an amateur project, and the design is clunky, but it may be instructive. The files are here:
> XPS is and open cell foam (eXtruded PolyStyrene.)
http://groups.yahoo.com/group/boatdesign/files/Dingbat/
I don't think you have to join the group to see them. Joining isn't a problem in any case.
There as a fad for this sort of construction back in the 1970s or thereabouts. It didn't catch on for amateurs. I think the problems of getting a fair surface outweigh any benefits.
If the idea is to build a boat from fiberglass without plywood, another idea is to lay up glass panels on "table." The table would basically be a piece of thick ply with a laminate top, like a big piece of kitchen counter. You can lay up glass to the desired size, and the side next to table will be smooth as glass. Multihull designers Richard Woods and Derek Kelsall have built boats that way.
A problem common to a lot of strong materials is that a panel that is strong enough is not stiff enough. Pure glass panels would require different framing than ply which is stiffer for its strength.
Peter
On Fri, Dec 31, 2010 at 1:07 PM, otter55806<otter55806@...>wrote:Hey Chester,
Glad to read about you and EstherMae! To refresh your memory, you let me park my van and boat trailer at your place while I was off on Drifter, my Bolger Bantam. How I wish I was there now. We had freezing rain here in Duluth last night.
Bob,
Do you use your Bantam on Lake Superior, or in the bay, or any of the lakes up north, like Vermilion or Kabetogama? I'm stuck in the Cities now but I'd love to see your boat when I head back to the Orr area during summer.
fred s.
What you want is one of the Urethane foams, not XPS. XPS is and open cell foam (eXtruded PolyStyrene.)
--- Inbolger@yahoogroups.com, "Christopher C. Wetherill" <wetherillc@...> wrote:
>
> This stuff is 24x96x1.5 under $15 and claims moisture resistance Pink
> Board
> <http://www.homedepot.com/h_d1/N-5yc1vZ1xhw/R-100320293/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053>.
> They also list 48x96x2 for under $25.
>
> Chris
>
> On 12/30/2010 5:06 PM, Chester Young wrote:
> >
> >
> > The top of the exterior chine is just out of the water at the #3 frame
> > location when at rest. With three layers of 5/8" foam plus epoxy and
> > fiberglass I should have sufficient clearance at the chine. I plan to
> > crown the floor slightly so that the water is forced to the scuppers.
> > The determined height issue is related to the price of the foam, it is
> > damned expensive, that is why I wonder what experience others have had
> > with other foams under similar circumstance. Since the floor will be
> > walked on and inevitably I will drop an anchor on it I plan to use
> > some substantial fiberglass as the cover. My standard anchor is a
> > 12kg Bruce. I switched from a Danforth after not being able to catch
> > a grip during a drift algae bloom, the flukes just jammed full of
> > algae and away we went. It took several sets to find a spot that the
> > anchor get settle to the bottom through.
> >
> > ~Caloosarat
> >
> > *From:*bolger@yahoogroups.com[mailto:bolger@yahoogroups.com] *On
> > Behalf Of *Mark Albanese
> > *Sent:* Thursday, December 30, 2010 4:46 PM
> > *To:*bolger@yahoogroups.com
> > *Subject:* [bolger] Re: foam sandwich retrofit question
> >
> > This is a perennial controversy here. Probably in the minority, I
> > think the concern is overstated. My 15 year old boat with poured in
> > foam, decked end chambers is worn and scraped and checked all over
> > now, but after having spent its entire life outside in the PNW shows
> > no rot adjacent to the foam.
> >
> > Your plan to glue down and encapsulate the foam completely should
> > provide sufficient peace of mind. I question whether the two inch
> > thick floor gets you high enough to be self bailing tho.
> >
> > Mark
> >
> > On Dec 30, 2010, at 12:13 PM, caloosarat wrote:
> >
> > I have a couple of knowledgeable friends who think I am asking for
> > trouble as moisture will get under the foam and rot the plywood hull.
> >
> >
>
You can get 2" thick closed cell foam at some home stores (Home Depot & Lowes stores.) Varies by location.
--- Inbolger@yahoogroups.com, "caloosarat" <chester@...> wrote:
>
> I am in the process of a major retro fit on EstherMae, my Tennessee. She was built in 92, purchased by me Christmas Eve of 2005 and much of the superstructure is due for rework. The first area to be rebuilt is the forward deck, this has resulted in the deck being removed from #1 frame back to the #3. It will not be replaced leaving the forward area from #1 to #3 open. I have cut the #2 frame at the top to allow for access to the very front and it has made handling the anchor so much nicer. I have 24"x24" Bomar hatch that is being installed in the face of the #3 frame to allow access from the cabin into the new forward cockpit.
> My question is related to the use of foam to raise the floor at least 2" so that the forward cockpit will be self draining via scuppers cut through the sides just forward of #3. 2" is the minimum to get above the exterior chine, it may require more to keep the floor above water when resting but that is to be determined. A local supplier of divinycell has 4'x8'x5/8" sheets available but they are $140 per sheet. I see some reference to blue board in the archives but nothing specific to enclosing such a foam as a floor that will be exposed to the outside. I will cover the forward cockpit when not being used but the reality is that there will times when it will be exposed for days, either due to extended use or laziness about installing the canvas. What has been the experience of this group with such an install of foam board? I am getting help from a couple of friends who both spent many years in a boat yard, building new fiberglass boats and working on older boats of various types and they express caution about encapsulating foam as it could breed rot.
>
> Thanks in advance Caloosarat
>
Lots more work
HJ
HJ
On 12/31/2010 12:06 PM, Christopher C. Wetherill wrote:All this discussion has brought to mind an old question I have been pondering. Has anyone built an Instant Boat from 1/2" pink board with fiberglass on both sides? Issues I have been considering
1) easier to work than plywood
2) slightly less costly than plywood
3) not as stiff
4) possibly lighter than plywood.
I suspect that the need to glass both sides will result in no savings of cost or weight.
Chris
1) easier to work than plywood
2) slightly less costly than plywood
3) not as stiff
4) possibly lighter than plywood.
I suspect that the need to glass both sides will result in no savings of cost or weight.
Chris
Hey Chester,
Glad to read about you and EstherMae! To refresh your memory, you let me park my van and boat trailer at your place while I was off on Drifter, my Bolger Bantam. How I wish I was there now. We had freezing rain here in Duluth last night.
The Bantam is a perfect example of Bolger's take on what you're asking. When he did the Bantam upgrade, what he did to make the hulls deeper to give more distance from the waterline to the underside of the bridge deck is more or less what you are looking into, but sort of in reverse. After the hull was built to the original plan he called for laminating layers of plain old cheap blue, pink, etc foam to the bottom, using thickened epoxy, then the sides of the extention (1/4" ply) were epoxied on. Then you were to use spray foam (cans)and pour epoxy along the sides to fill gaps, then epoxy on the new bottom. I remember a discussion years ago where group members were wondering if other glue could be used as it took a lot of epoxy to laminate the 6 inches or so of added foam to three hulls, but I would not chance it. Best to experiment on throw away, cheap, small boats, not on major projects. I also did something Bolger did not have on the plans that is most similar to what you want to do. The anchor and line storage on the Bantam at the bow of the main hull is so deep I could not reach the bottom no matter how I tried. I think you would have to have the arms of a pro basketball player to reach the bottom. After doing the double bottoms it seemed like a no brainer to raise the floor. I cut and epoxied foam to the original bottom, spray foamed and poured epoxy along the sides, cut and fit a new top and epoxied it into place. I then did thickened epoxy fillets around the edges, not so much for structural strength as to make sure the edges were sealed so water would not get into the sealed area. I raised it enough so that it was now above the static water line so drain holes could be drilled, where as the original floor was below the water line, so the water that got in had to be hand bailed/sponged out. Pretty much what you are talking about.
Yes, there is controversy over so called sealed areas. Yes, I'm sure condensation could become a problem down the road. But if PCB thought this would work, I went with it. He knew everything with boats is a compromise, and that all boats eventually need repair; and that one of the good things about plywood epoxy boats is the relative ease of repair. There is no such thing as building a boat in such a way as to never need maintenance and repair. Even the simple aluminum skiff can be holed on a rock, reef, or oyster bar and now needs to be dragged off to someone who can weld aluminum.
Bob
Glad to read about you and EstherMae! To refresh your memory, you let me park my van and boat trailer at your place while I was off on Drifter, my Bolger Bantam. How I wish I was there now. We had freezing rain here in Duluth last night.
The Bantam is a perfect example of Bolger's take on what you're asking. When he did the Bantam upgrade, what he did to make the hulls deeper to give more distance from the waterline to the underside of the bridge deck is more or less what you are looking into, but sort of in reverse. After the hull was built to the original plan he called for laminating layers of plain old cheap blue, pink, etc foam to the bottom, using thickened epoxy, then the sides of the extention (1/4" ply) were epoxied on. Then you were to use spray foam (cans)and pour epoxy along the sides to fill gaps, then epoxy on the new bottom. I remember a discussion years ago where group members were wondering if other glue could be used as it took a lot of epoxy to laminate the 6 inches or so of added foam to three hulls, but I would not chance it. Best to experiment on throw away, cheap, small boats, not on major projects. I also did something Bolger did not have on the plans that is most similar to what you want to do. The anchor and line storage on the Bantam at the bow of the main hull is so deep I could not reach the bottom no matter how I tried. I think you would have to have the arms of a pro basketball player to reach the bottom. After doing the double bottoms it seemed like a no brainer to raise the floor. I cut and epoxied foam to the original bottom, spray foamed and poured epoxy along the sides, cut and fit a new top and epoxied it into place. I then did thickened epoxy fillets around the edges, not so much for structural strength as to make sure the edges were sealed so water would not get into the sealed area. I raised it enough so that it was now above the static water line so drain holes could be drilled, where as the original floor was below the water line, so the water that got in had to be hand bailed/sponged out. Pretty much what you are talking about.
Yes, there is controversy over so called sealed areas. Yes, I'm sure condensation could become a problem down the road. But if PCB thought this would work, I went with it. He knew everything with boats is a compromise, and that all boats eventually need repair; and that one of the good things about plywood epoxy boats is the relative ease of repair. There is no such thing as building a boat in such a way as to never need maintenance and repair. Even the simple aluminum skiff can be holed on a rock, reef, or oyster bar and now needs to be dragged off to someone who can weld aluminum.
Bob
--- Inbolger@yahoogroups.com, "caloosarat" <chester@...> wrote:
>
> I am in the process of a major retro fit on EstherMae, my Tennessee. She was built in 92, purchased by me Christmas Eve of 2005 and much of the superstructure is due for rework. The first area to be rebuilt is the forward deck, this has resulted in the deck being removed from #1 frame back to the #3. It will not be replaced leaving the forward area from #1 to #3 open. I have cut the #2 frame at the top to allow for access to the very front and it has made handling the anchor so much nicer. I have 24"x24" Bomar hatch that is being installed in the face of the #3 frame to allow access from the cabin into the new forward cockpit.
> My question is related to the use of foam to raise the floor at least 2" so that the forward cockpit will be self draining via scuppers cut through the sides just forward of #3. 2" is the minimum to get above the exterior chine, it may require more to keep the floor above water when resting but that is to be determined. A local supplier of divinycell has 4'x8'x5/8" sheets available but they are $140 per sheet. I see some reference to blue board in the archives but nothing specific to enclosing such a foam as a floor that will be exposed to the outside. I will cover the forward cockpit when not being used but the reality is that there will times when it will be exposed for days, either due to extended use or laziness about installing the canvas. What has been the experience of this group with such an install of foam board? I am getting help from a couple of friends who both spent many years in a boat yard, building new fiberglass boats and working on older boats of various types and they express caution about encapsulating foam as it could breed rot.
>
> Thanks in advance Caloosarat
>
On Thu, Dec 30, 2010 at 2:13 PM, caloosarat<chester@...>wrote:I have scanned through some of the archives regarding use of foam panels.
Closed-cell styrofoam (blue foam) doesn't really have a problem with water absorption. I've buried plenty of it as insulation next to basement walls. It does degrade badly, however, under UV light. It can take a compression load, as long as it's not point source. Cover the foam with a sheet of 1/4 inch ply (or 3/8 if you're worried) and it should be fine.
fred s.
divinycell is a structural foam formulated to give the highest strength to weight ratio. You do not need that for your application. Pink board will be fine (ask at the lumber store for the foam board for below ground use)
As for foam causing rot. It has to have moisture penetrate it. Happens with iceboxes and fridges. Humidity penetrates the the fiberglass and into the foam and then condenses at the due point within the foam. Happens in fiberglass boats as well. then the freeze thaw cycle sets up problems in these parts. Blisters. Soaking wet foam that no longer insulates.
In your situation you will not have these problems. In making an ice box, bonding aluminum foil or other moisture proof material to the foam will prevent moisture from penetrating and condensing. Fiberglass over the whole.
Eric
As for foam causing rot. It has to have moisture penetrate it. Happens with iceboxes and fridges. Humidity penetrates the the fiberglass and into the foam and then condenses at the due point within the foam. Happens in fiberglass boats as well. then the freeze thaw cycle sets up problems in these parts. Blisters. Soaking wet foam that no longer insulates.
In your situation you will not have these problems. In making an ice box, bonding aluminum foil or other moisture proof material to the foam will prevent moisture from penetrating and condensing. Fiberglass over the whole.
Eric
--- Inbolger@yahoogroups.com, "Chester Young" <chester@...> wrote:
>
> The top of the exterior chine is just out of the water at the #3 frame
> location when at rest. With three layers of 5/8" foam plus epoxy and
> fiberglass I should have sufficient clearance at the chine. I plan to crown
> the floor slightly so that the water is forced to the scuppers. The
> determined height issue is related to the price of the foam, it is damned
> expensive, that is why I wonder what experience others have had with other
> foams under similar circumstance. Since the floor will be walked on and
> inevitably I will drop an anchor on it I plan to use some substantial
> fiberglass as the cover. My standard anchor is a 12kg Bruce. I switched
> from a Danforth after not being able to catch a grip during a drift algae
> bloom, the flukes just jammed full of algae and away we went. It took
> several sets to find a spot that the anchor get settle to the bottom
> through.
>
>
>
> ~Caloosarat
>
>
>
> From:bolger@yahoogroups.com[mailto:bolger@yahoogroups.com] On Behalf Of
> Mark Albanese
> Sent: Thursday, December 30, 2010 4:46 PM
> To:bolger@yahoogroups.com
> Subject: [bolger] Re: foam sandwich retrofit question
>
>
>
>
>
> This is a perennial controversy here. Probably in the minority, I think the
> concern is overstated. My 15 year old boat with poured in foam, decked end
> chambers is worn and scraped and checked all over now, but after having
> spent its entire life outside in the PNW shows no rot adjacent to the foam.
>
>
>
> Your plan to glue down and encapsulate the foam completely should provide
> sufficient peace of mind. I question whether the two inch thick floor gets
> you high enough to be self bailing tho.
>
> Mark
>
>
>
> On Dec 30, 2010, at 12:13 PM, caloosarat wrote:
>
> I have a couple of knowledgeable friends who think I am asking for trouble
> as moisture will get under the foam and rot the plywood hull.
>
Chris
On 12/30/2010 5:06 PM, Chester Young wrote:The top of the exterior chine is just out of the water at the #3 frame location when at rest. With three layers of 5/8” foam plus epoxy and fiberglass I should have sufficient clearance at the chine. I plan to crown the floor slightly so that the water is forced to the scuppers. The determined height issue is related to the price of the foam, it is damned expensive, that is why I wonder what experience others have had with other foams under similar circumstance. Since the floor will be walked on and inevitably I will drop an anchor on it I plan to use some substantial fiberglass as the cover. My standard anchor is a 12kg Bruce. I switched from a Danforth after not being able to catch a grip during a drift algae bloom, the flukes just jammed full of algae and away we went. It took several sets to find a spot that the anchor get settle to the bottom through.
~Caloosarat
From:bolger@yahoogroups.com[mailto:bolger@yahoogroups.com]On Behalf OfMark Albanese
Sent:Thursday, December 30, 2010 4:46 PM
To:bolger@yahoogroups.com
Subject:[bolger] Re: foam sandwich retrofit question
This is a perennial controversy here. Probably in the minority, I think the concern is overstated. My 15 year old boat with poured in foam, decked end chambers is worn and scraped and checked all over now, but after having spent its entire life outside in the PNW shows no rot adjacent to the foam.
Your plan to glue down and encapsulate the foam completely should provide sufficient peace of mind. I question whether the two inch thick floor gets you high enough to be self bailing tho.
Mark
On Dec 30, 2010, at 12:13 PM, caloosarat wrote:
I have a couple of knowledgeable friends who think I am asking for trouble as moisture will get under the foam and rot the plywood hull.
The top of the exterior chine is just out of the water at the #3 frame location when at rest. With three layers of 5/8” foam plus epoxy and fiberglass I should have sufficient clearance at the chine. I plan to crown the floor slightly so that the water is forced to the scuppers. The determined height issue is related to the price of the foam, it is damned expensive, that is why I wonder what experience others have had with other foams under similar circumstance. Since the floor will be walked on and inevitably I will drop an anchor on it I plan to use some substantial fiberglass as the cover. My standard anchor is a 12kg Bruce. I switched from a Danforth after not being able to catch a grip during a drift algae bloom, the flukes just jammed full of algae and away we went. It took several sets to find a spot that the anchor get settle to the bottom through.
~Caloosarat
From:bolger@yahoogroups.com [mailto:bolger@yahoogroups.com]On Behalf OfMark
Albanese
Sent:Thursday, December 30, 2010 4:46 PM
To:bolger@yahoogroups.com
Subject:[bolger] Re: foam sandwich retrofit question
This is a perennial controversy here. Probably in the minority, I think the concern is overstated. My 15 year old boat with poured in foam, decked end chambers is worn and scraped and checked all over now, but after having spent its entire life outside in the PNW shows no rot adjacent to the foam.
Your plan to glue down and encapsulate the foam completely should provide sufficient peace of mind. I question whether the two inch thick floor gets you high enough to be self bailing tho.
Mark
On Dec 30, 2010, at 12:13 PM, caloosarat wrote:
I have a couple of knowledgeable friends who think I am asking for trouble as moisture will get under the foam and rot the plywood hull.
This is a perennial controversy here. Probably in the minority, I think the concern is overstated. My 15 year old boat with poured in foam, decked end chambers is worn and scraped and checked all over now, but after having spent its entire life outside in the PNW shows no rot adjacent to the foam.
Your plan to glue down and encapsulate the foam completely should provide sufficient peace of mind. I question whether the two inch thick floor gets you high enough to be self bailing tho.
Mark
On Dec 30, 2010, at 12:13 PM, caloosarat wrote:
I have a couple of knowledgeable friends who think I am asking for trouble as moisture will get under the foam and rot the plywood hull.
I have scanned through some of the archives regarding use of foam panels. Most all of it deals with flotation. My question is about using it for raising a bottom, in this case on a Tennessee (EstherMae). I have removed the deck from #1 to #3 frames and do not intend to replace the deck. I now need to raise the floor at lest 2" to make the new forward cockpit self draining via scuppers just ahead of the #3 frame. I am looking at divinycell sandwiched with epoxy and covered with fiberglass. I have a couple of knowledgeable friends who think I am asking for trouble as moisture will get under the foam and rot the plywood hull. What is the experience of others in the group using foam this way? Has anyone used blue board in such a fashion? The deck is already removed and I went out on Christmas day, the ability to walk forward and set the anchor is awesome, the deck will not be going back on.
~Caloosarat
~Caloosarat
I am in the process of a major retro fit on EstherMae, my Tennessee. She was built in 92, purchased by me Christmas Eve of 2005 and much of the superstructure is due for rework. The first area to be rebuilt is the forward deck, this has resulted in the deck being removed from #1 frame back to the #3. It will not be replaced leaving the forward area from #1 to #3 open. I have cut the #2 frame at the top to allow for access to the very front and it has made handling the anchor so much nicer. I have 24"x24" Bomar hatch that is being installed in the face of the #3 frame to allow access from the cabin into the new forward cockpit.
My question is related to the use of foam to raise the floor at least 2" so that the forward cockpit will be self draining via scuppers cut through the sides just forward of #3. 2" is the minimum to get above the exterior chine, it may require more to keep the floor above water when resting but that is to be determined. A local supplier of divinycell has 4'x8'x5/8" sheets available but they are $140 per sheet. I see some reference to blue board in the archives but nothing specific to enclosing such a foam as a floor that will be exposed to the outside. I will cover the forward cockpit when not being used but the reality is that there will times when it will be exposed for days, either due to extended use or laziness about installing the canvas. What has been the experience of this group with such an install of foam board? I am getting help from a couple of friends who both spent many years in a boat yard, building new fiberglass boats and working on older boats of various types and they express caution about encapsulating foam as it could breed rot.
Thanks in advance Caloosarat
My question is related to the use of foam to raise the floor at least 2" so that the forward cockpit will be self draining via scuppers cut through the sides just forward of #3. 2" is the minimum to get above the exterior chine, it may require more to keep the floor above water when resting but that is to be determined. A local supplier of divinycell has 4'x8'x5/8" sheets available but they are $140 per sheet. I see some reference to blue board in the archives but nothing specific to enclosing such a foam as a floor that will be exposed to the outside. I will cover the forward cockpit when not being used but the reality is that there will times when it will be exposed for days, either due to extended use or laziness about installing the canvas. What has been the experience of this group with such an install of foam board? I am getting help from a couple of friends who both spent many years in a boat yard, building new fiberglass boats and working on older boats of various types and they express caution about encapsulating foam as it could breed rot.
Thanks in advance Caloosarat