Polyester and Epoxy
My news
cured and sanded epoxy on stich and glue? My plan is to prime the entire
hull with epoxy for a good bind before the application of
fiberglass/polyester skin.
I want to introduce this idea to the poor fishermen in the Philippines for
economic reason.
cavelamb
Advice? Yeah - don't.
Bruce In Bangkok
Polyester does not bond very well to epoxy. Most authorities advise
not to use this method.
The "old" system was to use thin polyester resin to impregnate the
wood. Then use polyester resin to "glue" it together. Many boats were
built this way in the early days of "fiberglass" construction.
I think I'd question your idea. Why not just use waterproof plywood to
build boats? It has been done successfully for years now and I would
guess that the Filipinos are well aware of how to build boats.
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
Todd
The epoxy will be softened by the polyester and MEK. It will be a big
mess.
IanM
The *only* way I have ever heard of to get a satisfactory bond with
standard polyester resin over normal epoxies is wait several months for
the epoxy to totally cure, abrade the **** out of it and apply a barrier
and bonding coat of G4 Pond Sealer then lay up the polyester laminate
while the G4 is still tacky. Ideally the area of epoxy to be overcoated
should be kept to a minimum as G4 works very well on wood and other
porous substrates.
Its doubtful whether full sheathing on a working boat will, in the long
term, be maintained well enough to prevent water penetration and
accelerated rot.
If the intention is to prevent worm damage, it may be a reasonable
solution, but the initial expense is likely to be high enough that only
rich fishermen can afford it, even though they will save money over the
life of the vessel. I don't think encouraging the use of large
quantities of expensive resins is going to do much for a sustainable
fishing industry in poor communities. Expensive boats with large loans
outstanding on them *will* lead to overfishing as the boat owners do
what it takes to reduce their debt. I fear that this may well seriously
worsen the circumstances of poor fishermen.
--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL:
mscres
"Bruce In Bangkok" <decypher...@sig.line> wrote in message
news:ein3m4deg93uqh1fc...@4ax.com...
They are still using the old practice of cutting trees to make a dug out
canoe for the bottom hull with extented sides made of plywood. The dug out
canoes are being sold to the local fishermen by those illegal tree cutters.
I like to introduce the stick and glue to eliminate the dug out canoe which
will be cheaper for them and will save the trees. This is the native Banca
using outriggers on both sides.
http://www.pixelmap.ca/canoesailing/
Bruce In Bangkok
Will it really be cheaper? I ask as in Thailand a bunch of guys came
over to show the natives how to build boats and the fishermen didn't
buy it. The local built boats were cheaper and longer lasting.
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
Two meter troll
> "Bruce In Bangkok" <decypher.addr...@sig.line> wrote in messagenews:ein3m4deg93uqh1fc...@4ax.com...
>
> - Show quoted text -
for their own good.......right.
My news
save them time to build the boat. I asked some boat makers in the south of
manila that their waiting time for the dugout canoe is about four to five
months. The price is not cheap for a very crude work that they still have to
finish. It is the most expensive part of the boat and mostly came from
illegal cutting.
You can see from the link I provided earlier that the price of the boat can
go up to 3000 dollars which is not affordable for many native filipinos.
"Bruce In Bangkok" <decypher...@sig.line> wrote in message
news:sni6m4hsfkv46s0of...@4ax.com...
Todd
> It will be cheaper for them if they can eliminate the dugout canoe and will
> save them time to build the boat. I asked some boat makers in the south of
> manila that their waiting time for the dugout canoe is about four to five
> months. The price is not cheap for a very crude work that they still have to
> finish. It is the most expensive part of the boat and mostly came from
> illegal cutting.
> You can see from the link I provided earlier that the price of the boat can
> go up to 3000 dollars which is not affordable for many native filipinos.
>
I have on my desk at home a couple of articles from early issues of
the CoEvolution Quarterly about the work John Todd was doing in
Central America with similar aims. He had a boat designed that would
be the sea going "pick-up" for indigenous people. You may be able to
find some information on this project although I haven't seen much
online. (I may rectify that soon however.) As I remember there turned
out to be quite a strong reaction against his efforts from entrenched,
wealthy interests that did not want any sort of socio-economic
progress happening 'round those parts.
Two meter troll
> It will be cheaper for them if they can eliminate the dugout canoe and will
> save them time to build the boat. I asked some boat makers in the south of
> manila that their waiting time for the dugout canoe is about four to five
> months. The price is not cheap for a very crude work that they still have to
> finish. It is the most expensive part of the boat and mostly came from
> illegal cutting.
> You can see from the link I provided earlier that the price of the boat can
> go up to 3000 dollars which is not affordable for many native filipinos.
>
>
> - Show quoted text -
you ever wonder why those boat makers are still waiting for those
dugouts?
they have a ton of programs to teach them modern boat building and
they dont use them.
the natives dont like the stich and glue boats. the boats dont behave
the way those dugouts behave and they look funny. all that framing
inside getting in the way.
have you spoken to the poor and found what they want in a boat?
my guess is that they will still not be able to afford your stich and
glue monstrosity mostly because they cant take a chance on if it will
work or not.
dont spend time talking to those with cash that wont actually use the
boat talk to the folks who will be depending on the boat to not
starve. the you will get some answers as to why those boat builders
are sitting around drinking wine and waiting for the illeagle logs to
be cut.
Bruce In Bangkok
>It will be cheaper for them if they can eliminate the dugout canoe and will
>save them time to build the boat. I asked some boat makers in the south of
>manila that their waiting time for the dugout canoe is about four to five
>months. The price is not cheap for a very crude work that they still have to
>finish. It is the most expensive part of the boat and mostly came from
>illegal cutting.
>You can see from the link I provided earlier that the price of the boat can
>go up to 3000 dollars which is not affordable for many native filipinos.
>
You seem to be implying that the poor benighted fishermen don't really
know much about boats and you are going to teach the ignorant people a
new and better way. Sort of a missionary saving the pagans idea, which
is often a trait of people who really don't have a great deal of
experience in the subject, or area.
My experience, based on asking questions, not on attempting to convert
anyone, is that in most areas the local watermen do in fact have a
fairly good idea of what type of boat is most suitable to their
particular type of work.
For example: In Thailand 99.9 percent of all fishing boats are built
of wood. Big fishing boats - 80 footers or bigger. Recently, while I
was in the yard an 80 footer was right behind me and I asked the owner
why not build with steel. He replied that of course steel was cheaper
but a few years ago some boats were built from steel and the boats had
a lot of problems that the wooden boats didn't have so the owners
generally didn't want steel.
My point isn't that steel is better or worse then wood, rather that
local watermen usually do know what boats fit their purpose.
Given that the Filipinos are a pretty innovative people and have a
world of experience working in foreign countries, adapting foreign
ideas - see jeepney, for example - etc. It seems unlikely that glued
plywood is going to be a real surprise to them.
Re the dugout style boats you mention, I can think of at least one
reason to build them that way - they will be more stable and have a
much easier motion when fishing that a lighter plywood boat.
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
My news
"Bruce In Bangkok" <decypher...@sig.line> wrote in message
I'm very aware that many people are reluctant to make a big change to the
things that they are accustomed for generations. My only intention is to
show that there is an option for them to use in replace of the bottom hull.
They will still build a basic Banca but less expensive and faster to make.
My plan is to fabricate a similar type of the dugout canoe from stich and
glue and ask one of the natives to build a Banca from it. I believe this
approach will be acceptable because the real intention is the affordability
for others. I estimate that the cost can be cut to approximately 30% less
due to elimination the laborous dugout canoe and the island to island
transport. Imagine that some guys will go to the mountain, find the right
tree with the right size, cut it down and dug it out for a crudely made
canoe in manual labor and finally deliver it to another island. The plywood
is available everywhere in the Philippines but the available composites are
fibergalss and polyester. The only available epoxy is the thick, grey
generic type.
cavelamb
"The road to hell is paved with good intentions"
?
My news
"My news" <msc...@cox.net> wrote in message
news:foV8l.66734$lX6....@newsfe06.iad...
BTW, The easy motion and stability of the Banca basically relies from it's
length. The common size for a small fisherman ranges from 28 to 32 foot
long. This is based from most local fishermen I spoke with. The 32 footers
are more dependable in the open. They are lightweight indeed. The sides are
made of quarter inch plywood. The dugout canoe is three quarter inch thick
and an inch on the bottom. They will like it if the boat will be made even
lighter because they carry Gill nets with plenty of sinks. They can use
extra capacity to carry more nets that will result to higher yield. In
addition, The haul can be made even wider for more buoyancy if stitch and
glue is used.
>
Two meter troll
"I belive the road to hell is actually paved with frozen door to door
salesmen. young demons ice skate down it on nice days" Terry pratchet,
good omens
Bruce In Bangkok
I'm not trying to get you to abandon your plan, I'm just saying that
the local lads aren't as clueless as they may seem. Over the years I
have questioned a lot of things that seemed, from a Western viewpoint
to be rational, and gotten perfectly logical answers why they aren't
acceptable to the users.
Another example: Why do Thai fishermen use "long tailed" motors? I
asked a couple of fishermen - "why not outboards". the answer was,
"because the long Tails cost less, last longer, use less fuel and
work".
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
Pirateer guy
>is available everywhere in the Philippines but the available composites are
>fibergalss and polyester. The only available epoxy is the thick, grey
>generic type.
>
Then in that case you aren't stitch and gluing anything. You have no
glue.
Maybe the locals know that.
Heikki
Don't be too harsh! Boats have been stitched together long before anyone had
epoxy. It might be quite possible to get structural strength from the
stitches, and cover up with something (poly+glass) only to keep it
watertight.
-H
Bruce In Bangkok
True, but as soon as nails became available they stopped tying their
boats together....Stitching certainly works - when there is no other
solution.
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
Pirateer guy
Agreed, but you wouldn't build commercial boats out of it.
Were talking work boats here, not weekenders at the beach.
Bruce In Bangkok
Boats that guys use to earn a living... Commercial? Small business,
maybe, but I'd call them commercial..
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
Ineke and Ian
damaged during rock-bashing/ white-water canoeing - polyester patches were
not durable and could be ripped off the damaged canoe, with very little
effort - where as epoxy patches showed much superior adhesion.
Applying polyester over epoxy would result in a useless bond - suggest you
test your proposed method with a small piece of fibreglass/polyester applied
to the stich and glue surface and try removing it after about one week.
I would use epoxy - apart from its superior adhesion and water resistance,
it is not as toxic as polyester - that sweet smell of polyester is cancer
producer whereas the nasty chemical in epoxy is not sufficiently volatile to
be a problem - just prevent skin contact with epoxy.
Where did I acquire this wisdom - building small multihulls using epoxy,
during the previous 17 years - see the Yacht Research Homepage under Project
Windrigger.
Ian Smith
"My news" <msc...@cox.net> wrote in message
news:fUc8l.31003$4u2....@newsfe02.iad...
cavelamb
Looking over your work reminded me of a project I wanted to try some time back.
I thought it might be interesting to build a "strip planked" hull using strips
of blue construction foam and toothpicks. then glass inside and out - with
epoxy, of course...
Thanks for sharing.
Richard
axolotl
> I thought it might be interesting to build a "strip planked" hull using
> strips
> of blue construction foam and toothpicks. then glass inside and out - with
> epoxy, of course...
Richard,
Back in the 60's Popular Mechanics / Science and Mechanics / Mechanics
Illustrated had a building article:
"Foamy, the boat you build with a razor blade"
I haven't been able to find it online.
Kevin Gallimore
cavelamb
Cool.
Did you try the PM archives?
Richard
axolotl
>
> Did you try the PM archives?
Didn't see it. My unreliable 40 year old recollection is that it was in
Science and Mechanics.
Kevin Gallimore