Re: Plywood Alternatives
Sorry I haven't been following the thread. I've been wondering about
the lightweight glassed mat panels used for shell-over-frame walls and
roof on semi-trailers. Probably only useful for S&G on a multi-chined
hull.
Also seehttp://www.gaboats.com/.Montfort uses aircraft dacron,
heat-shrunk. This link also relevant to current threads on 'shoulder
boats' and 'synthetic fabric hulls.'
Best,
Trenton Matt
the lightweight glassed mat panels used for shell-over-frame walls and
roof on semi-trailers. Probably only useful for S&G on a multi-chined
hull.
Also seehttp://www.gaboats.com/.Montfort uses aircraft dacron,
heat-shrunk. This link also relevant to current threads on 'shoulder
boats' and 'synthetic fabric hulls.'
Best,
Trenton Matt
There is a point in size when the glass needed outways the money
saved not useing ply on all. For S&G it would be surly be easier to
just use ply and light glass and not worry about it breaking...
Jon
saved not useing ply on all. For S&G it would be surly be easier to
just use ply and light glass and not worry about it breaking...
Jon
--- Inbolger@yahoogroups.com, "oarmandt" <oarman89@...> wrote:
>
> I have been experimenting with an alternative construction, suitable
> for small boats. The ideal panel material would be available in the
> ubiquitous big box stores, resist rot, be lightweight, and of course
> cheap. I am using insulating foam, specifically 3/4" thick Rmax,
Inc.
> insulating foam. See:
>http://www.rmaxinc.com/wall-r-matte-plus3.asp
>
> Home Depot carries it in 1/2" and 3/4" thicknesses. This material
> comes with kraft paper and foil covers both sides. It is very stiff
> with the paper on and quite flimsy without. I have built a sliding
> seat rowing shell out of it, to this plan:
>
>http://koti.kapsi.fi/hvartial/scull1/scull1.htm
>
> It is basic stitch and glue construction. Of course the foam cannot
> take being wired together, so I taped it up outside with masking
tape
> until the inside seams were glassed. The paper had to be stripped
off
> both sides of the foam in order to make the twist in the bottom
panels
> toward the ends. In other places, I left the paper on. I glassed
the
> whole outside. I glassed (with Raka epoxy) the whole bottom inside
> plus up to the gunwales in the middle compartment where all the load
> is concentrated. The foam with one layer of 6 oz glass each side is
> very stiff. I have not tested to destruction yet, but I feel that
it
> is plenty tough enough for a human-powered boat. A previous rowing
> shell was a wood truss covered with aircraft fabric and dope. The
> foam and glass seems like it would take more abuse than the fabric
and
> I got 15 years out of that boat before a 3-foot slash swamped it.
>
> This type of foam is maybe a bit short on compressive strength for
the
> ideal composite sandwich. I think it is adequate if you don't mind
> picking up a few dents in service. It takes some attention to
> reinforce where point loads attach to the hull. My sliding seat rig
> is built in, attached to plywood bulkheads that are glass taped to
the
> hull bottom and sides. For all but the most slender hulls, the
paper
> will probably have to come off at least one side to make the
bends.
>
> I have had a few outings in it. No issues with the construction
have
> turned up yet.
>
> If you are going to glass both sides of a panel anyway, I think you
> should consider foam instead of cheap plywood. This is especially
so
> if light weight is important. This construction could extend the
> range of boat sizes considered car-toppable. Flotation is built
in.
> If you can't bear the thought of standing on foam, maybe a hybrid
with
> ply bottom but foam sides, bulkheads and decks makes sense. Panel
> strength can be adjusted by varying the number or weight of the
> fiberglass layers.
>
> Doug
>
I have been experimenting with an alternative construction, suitable
for small boats. The ideal panel material would be available in the
ubiquitous big box stores, resist rot, be lightweight, and of course
cheap. I am using insulating foam, specifically 3/4" thick Rmax, Inc.
insulating foam. See:
http://www.rmaxinc.com/wall-r-matte-plus3.asp
Home Depot carries it in 1/2" and 3/4" thicknesses. This material
comes with kraft paper and foil covers both sides. It is very stiff
with the paper on and quite flimsy without. I have built a sliding
seat rowing shell out of it, to this plan:
http://koti.kapsi.fi/hvartial/scull1/scull1.htm
It is basic stitch and glue construction. Of course the foam cannot
take being wired together, so I taped it up outside with masking tape
until the inside seams were glassed. The paper had to be stripped off
both sides of the foam in order to make the twist in the bottom panels
toward the ends. In other places, I left the paper on. I glassed the
whole outside. I glassed (with Raka epoxy) the whole bottom inside
plus up to the gunwales in the middle compartment where all the load
is concentrated. The foam with one layer of 6 oz glass each side is
very stiff. I have not tested to destruction yet, but I feel that it
is plenty tough enough for a human-powered boat. A previous rowing
shell was a wood truss covered with aircraft fabric and dope. The
foam and glass seems like it would take more abuse than the fabric and
I got 15 years out of that boat before a 3-foot slash swamped it.
This type of foam is maybe a bit short on compressive strength for the
ideal composite sandwich. I think it is adequate if you don't mind
picking up a few dents in service. It takes some attention to
reinforce where point loads attach to the hull. My sliding seat rig
is built in, attached to plywood bulkheads that are glass taped to the
hull bottom and sides. For all but the most slender hulls, the paper
will probably have to come off at least one side to make the bends.
I have had a few outings in it. No issues with the construction have
turned up yet.
If you are going to glass both sides of a panel anyway, I think you
should consider foam instead of cheap plywood. This is especially so
if light weight is important. This construction could extend the
range of boat sizes considered car-toppable. Flotation is built in.
If you can't bear the thought of standing on foam, maybe a hybrid with
ply bottom but foam sides, bulkheads and decks makes sense. Panel
strength can be adjusted by varying the number or weight of the
fiberglass layers.
Doug
for small boats. The ideal panel material would be available in the
ubiquitous big box stores, resist rot, be lightweight, and of course
cheap. I am using insulating foam, specifically 3/4" thick Rmax, Inc.
insulating foam. See:
http://www.rmaxinc.com/wall-r-matte-plus3.asp
Home Depot carries it in 1/2" and 3/4" thicknesses. This material
comes with kraft paper and foil covers both sides. It is very stiff
with the paper on and quite flimsy without. I have built a sliding
seat rowing shell out of it, to this plan:
http://koti.kapsi.fi/hvartial/scull1/scull1.htm
It is basic stitch and glue construction. Of course the foam cannot
take being wired together, so I taped it up outside with masking tape
until the inside seams were glassed. The paper had to be stripped off
both sides of the foam in order to make the twist in the bottom panels
toward the ends. In other places, I left the paper on. I glassed the
whole outside. I glassed (with Raka epoxy) the whole bottom inside
plus up to the gunwales in the middle compartment where all the load
is concentrated. The foam with one layer of 6 oz glass each side is
very stiff. I have not tested to destruction yet, but I feel that it
is plenty tough enough for a human-powered boat. A previous rowing
shell was a wood truss covered with aircraft fabric and dope. The
foam and glass seems like it would take more abuse than the fabric and
I got 15 years out of that boat before a 3-foot slash swamped it.
This type of foam is maybe a bit short on compressive strength for the
ideal composite sandwich. I think it is adequate if you don't mind
picking up a few dents in service. It takes some attention to
reinforce where point loads attach to the hull. My sliding seat rig
is built in, attached to plywood bulkheads that are glass taped to the
hull bottom and sides. For all but the most slender hulls, the paper
will probably have to come off at least one side to make the bends.
I have had a few outings in it. No issues with the construction have
turned up yet.
If you are going to glass both sides of a panel anyway, I think you
should consider foam instead of cheap plywood. This is especially so
if light weight is important. This construction could extend the
range of boat sizes considered car-toppable. Flotation is built in.
If you can't bear the thought of standing on foam, maybe a hybrid with
ply bottom but foam sides, bulkheads and decks makes sense. Panel
strength can be adjusted by varying the number or weight of the
fiberglass layers.
Doug
Anytime heat gets to close to Tyvek it starts shrinking into a wads. A
cigaret but will burn a hole in it on contact. here is a calking that
can be used for a glue and the sight has everything you want to know
almost. The acid in Cedar will break it down.
http://www2.dupont.com/Tyvek_Construction/en_US/products/residential/pro
ducts/sealant.html
Jon
cigaret but will burn a hole in it on contact. here is a calking that
can be used for a glue and the sight has everything you want to know
almost. The acid in Cedar will break it down.
http://www2.dupont.com/Tyvek_Construction/en_US/products/residential/pro
ducts/sealant.html
Jon
I've witnessed the "flaming" of the surface of plastic bottles in
manufacturing. The bottles were moved through a gas flame, with the
blue part of the flame impinging on the surface of the plastic for
MAYBE 1 second. Nothing visual changed in the bottle. The bottles
then went directly to a printing process. I was told this step made
the ink adhere to the bottle.
IMO cardboard or semi-rigid plastic covered with glass fabric and
resin could be viable, but one may need to consider the substrate to
be simply a form with the FRP being the real structure. Not unlike
using various foam substrates.
manufacturing. The bottles were moved through a gas flame, with the
blue part of the flame impinging on the surface of the plastic for
MAYBE 1 second. Nothing visual changed in the bottle. The bottles
then went directly to a printing process. I was told this step made
the ink adhere to the bottle.
IMO cardboard or semi-rigid plastic covered with glass fabric and
resin could be viable, but one may need to consider the substrate to
be simply a form with the FRP being the real structure. Not unlike
using various foam substrates.
Hi Kevin, Dave and listmembers,
A friend of mine thought to try Tyvek as a kind of "japanese paper"
finish on some cabinet fronts. A year later it is delaminating.
Unfortunately I don't know what he used for adhesive. I'd be
interested to know the results of your tests.
I was told by an acquaintance, who was working for 3M at the time,
that the way to form a good bond on polyethelene involves "flaming the
surface"; he said something I didn't understand about this temporarily
altering the surface charge... or something like that. I seem to
recall that it was not a function of the heat. Please be cautious
though... contact cement and open flames are a combination to be
carefully avoided!
You might enjoy the record of my exploits in our local "Build-a-Boat"
competition, which allows CAD$100 of materials from the local
builders' supply store and 2 hours to make a boat.
http://buchwald.ca/archives/79
2003 was a dory, of sorts. That corrugated plastic is called Tenplast
around here, or Coroplast in the States.
2004 was a skin-on-frame kayak with Tenplast bulkheads, garden stake
stringers, and a polytarp skin.
2006, for which I do not have photos, was an outrigger canoe made out
of Sonotube.
Alas, the contest has not been held since then.
Regarding the cheap plywood discussion: I made a Sweet Pea several
years ago out of cheap luan. The thing is, I started the project and
got the hull stitched together, and then it sat in the backyard for 3
years before I got back to it. My dog even chewed a chunk out of the
garboard panel. After that, patched up, glassed outside and coated
inside, it held up to a lot of use. If had it to do over again, I'd
buy marine ply, though, considering how much work the whole thing was,
and how much I liked that boat once it was done.
Cheers,
- Charles
Charles Buchwald
Box 384
Salt Spring Island, BC V8K 2W1 Canada
email:charles@...
[Non-text portions of this message have been removed]
A friend of mine thought to try Tyvek as a kind of "japanese paper"
finish on some cabinet fronts. A year later it is delaminating.
Unfortunately I don't know what he used for adhesive. I'd be
interested to know the results of your tests.
I was told by an acquaintance, who was working for 3M at the time,
that the way to form a good bond on polyethelene involves "flaming the
surface"; he said something I didn't understand about this temporarily
altering the surface charge... or something like that. I seem to
recall that it was not a function of the heat. Please be cautious
though... contact cement and open flames are a combination to be
carefully avoided!
You might enjoy the record of my exploits in our local "Build-a-Boat"
competition, which allows CAD$100 of materials from the local
builders' supply store and 2 hours to make a boat.
http://buchwald.ca/archives/79
2003 was a dory, of sorts. That corrugated plastic is called Tenplast
around here, or Coroplast in the States.
2004 was a skin-on-frame kayak with Tenplast bulkheads, garden stake
stringers, and a polytarp skin.
2006, for which I do not have photos, was an outrigger canoe made out
of Sonotube.
Alas, the contest has not been held since then.
Regarding the cheap plywood discussion: I made a Sweet Pea several
years ago out of cheap luan. The thing is, I started the project and
got the hull stitched together, and then it sat in the backyard for 3
years before I got back to it. My dog even chewed a chunk out of the
garboard panel. After that, patched up, glassed outside and coated
inside, it held up to a lot of use. If had it to do over again, I'd
buy marine ply, though, considering how much work the whole thing was,
and how much I liked that boat once it was done.
Cheers,
- Charles
> Re: Plywood 101--
> Posted by: "figginsco"figginsco@...figginsco
> Fri Dec 5, 2008 11:02 am (PST)
>
> --- Inbolger@yahoogroups.com, "givifreak007" <givifreak007@...>
> wrote:
> >
> > --- Inbolger@yahoogroups.com, "Don" <dschurricanes@> wrote:
> > >
> > > Has anyone used AC 3ply plywood...to build a boat...of Phil's
> design..?
> > >
> > I'm planning on using a tyvek laminate (made with waterproof
> polyurethane) over double-
> > walled cardboard to build an Elegant Punt this Spring. I'm
> currently testing various grades
> > of glue and tyvek for the best bonding strength.
> >
> > Kevin
> >
> Hi Kevin
> right on, I have been thinking along those same lines. Would be
> interested in what your testing shows. No use all of us reinventing
> the wheel. How are you planning keeping the cardboard dry? You know
> there is a cardboard like plastic product used in sign making. Plastic
> supply companies carry it. Please keep us lunitics informed.
> Dave
Charles Buchwald
Box 384
Salt Spring Island, BC V8K 2W1 Canada
email:charles@...
[Non-text portions of this message have been removed]