On Jan 4, 6:55*pm, "My news" wrote:
Any advise or comment if I will use polyester and fiber glass on top of
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.

The epoxy will be softened by the polyester and MEK. It will be a big
mess.

Todd wrote:
On Jan 4, 6:55 pm, "My news" wrote:
Any advise or comment if I will use polyester and fiber glass on top of
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.

The epoxy will be softened by the polyester and MEK. It will be a big
mess.

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:

From my experience of building and repairing polyester/fibreglass canoes
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" wrote in message
...
Any advise or comment if I will use polyester and fiber glass on top of
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.

Ineke and Ian wrote:
From my experience of building and repairing polyester/fibreglass canoes
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" wrote in message
...
Any advise or comment if I will use polyester and fiber glass on top of
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.






Hi Ian,

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

cavelamb wrote:

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

axolotl wrote:
cavelamb wrote:

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

Cool.

Did you try the PM archives?

Richard

cavelamb wrote:


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