MMC wrote:
I posted a question on a open "discussion" group, and got a typical wise-ass
response, why am I surprised?
The question was based on the adage "epoxy over poly, but never poly over
epoxy". I don't know how well polyester or vinylester sticks to plywood, and
it was just a question.

Polyester is a poor substitute for epoxy when you're bonding to wood. It
doesn't bond nearly as well. If one were to apply epoxy over it, you'd
still have a weak bond between the wood and the filler, which would be
the weakest link in the chain, so to speak.

If guys building boats or refitting old boats can afford not to budget the
funds, why bother with building or refitting? Why not just go buy the boat
they want?

Good question.

On Tue, 27 Jul 2004 16:06:02 GMT, "MMC" wrote:

I posted a question on a open "discussion" group, and got a typical wise-ass
response, why am I surprised?
The question was based on the adage "epoxy over poly, but never poly over
epoxy". I don't know how well polyester or vinylester sticks to plywood, and
it was just a question.

Hi,

The problem is that if the wood gets damp the polyester resin will let
go, it doesn't have the same adhesive properties of epoxy.

For sticking polyester to wood you would need a bonding agent between
them. Something like POR 15 or a moisture curing polyurethane pond
sealer might do it, a though a trial would definitely be necessary.

For small areas or $$$ projects epoxy is the way to go, but if it's a
budget project and needs a lot of resin it would be worth checking out
the above.

cheers,
Pete.


If guys building boats or refitting old boats can afford not to budget the
funds, why bother with building or refitting? Why not just go buy the boat
they want?
MMC

"Brian Nystrom" wrote in message
...
MMC wrote:

Jim,
If these guys are fairing before laying up with epoxy, can't they use
poly
or vinylester resin with fairing filler or micro balloons? It'd be a lot
cheaper.

Perhaps they're more interested in doing it right than doing it cheaply.

Brian and Pete,
Thanks for the good answers. I'm trying to learn something here too.
MMC
"Pete C" wrote in message
...
On Tue, 27 Jul 2004 16:06:02 GMT, "MMC" wrote:

I posted a question on a open "discussion" group, and got a typical
wise-ass
response, why am I surprised?
The question was based on the adage "epoxy over poly, but never poly over
epoxy". I don't know how well polyester or vinylester sticks to plywood,
and
it was just a question.

Hi,

The problem is that if the wood gets damp the polyester resin will let
go, it doesn't have the same adhesive properties of epoxy.

For sticking polyester to wood you would need a bonding agent between
them. Something like POR 15 or a moisture curing polyurethane pond
sealer might do it, a though a trial would definitely be necessary.

For small areas or $$$ projects epoxy is the way to go, but if it's a
budget project and needs a lot of resin it would be worth checking out
the above.

cheers,
Pete.


If guys building boats or refitting old boats can afford not to budget
the
funds, why bother with building or refitting? Why not just go buy the
boat
they want?
MMC

"Brian Nystrom" wrote in message
...
MMC wrote:

Jim,
If these guys are fairing before laying up with epoxy, can't they use
poly
or vinylester resin with fairing filler or micro balloons? It'd be a
lot
cheaper.

Perhaps they're more interested in doing it right than doing it
cheaply.

"Ron White" wrote in message ...
Oops, I may have stepped in it again. I think I should have said it is my
understanding that he made several suggested lay-ups leaving the final
choice to my friend, the builder. I thank you and the other's who have
offered advice.
The hull on this boat is three layers of 1/2" ply on the bottoms and two
layers of 1/2" on the sides. It seems quite stout so the glass is just a
covering, I guess.
I have never done any wet lay-ups like Glenn sugested so the idea of
handling wetted out cloth with it's tendancy to become distorted kind of
worries me just having a small lay-up crew of one or two people. I would
have thought biaxial would be easier to handle than cloth due to it's
stiching. I used all biaxial on my boat but it was stiched to mat and laid
down dry, very easy to handle.

With that kind of planking, I understand the designer's response. All
what he needs is some protection against abrasion etc. - 9 oz. woven
would be great. Pick a fine weave: as Joel writes, it will require
less fairing and sanding.

Jacques
http://bateau.com

"Glenn Ashmore" wrote in message

I used the Tom Sawyer approach and got a bunch of volunteers. One
person mixing resin, two people wetting out and 3 people laying. We did
two layers of DB170 biax and one 6 oz. woven on my 45' hull in 6 hours.
After wetting out on a table made from a couple of sheets of melamine
we rolled the biax on 2" PVC pipe to carry it to the boat. The only
significant increase in cost was a couple of cases of beer when we
finished.

Glenn,

Did you ever get your home made fabric impregnator to work?

About how many yards / square meter of fabric did each 6 hour session manage
to lay up?

And how much experience did your wetting out team have?

Thanks

--
Evan Gatehouse

you'll have to rewrite my email address to get to me
ceilydh AT 3web dot net
(fools the spammers)

I use that same low tech approach since years: wet the fabric on a
large piece of cardboard, roll it and unroll on the hull BUT, some
time ago, I saw pictures of a home made impregnator on the web and
lost the bookmark.
Does anybody know about that? I would like to try.

Jacques Mertens
http://bateau.com

"Evan Gatehouse" wrote in message ...
"Glenn Ashmore" wrote in message

I used the Tom Sawyer approach and got a bunch of volunteers. One
person mixing resin, two people wetting out and 3 people laying. We did
two layers of DB170 biax and one 6 oz. woven on my 45' hull in 6 hours.
After wetting out on a table made from a couple of sheets of melamine
we rolled the biax on 2" PVC pipe to carry it to the boat. The only
significant increase in cost was a couple of cases of beer when we
finished.

Glenn,

Did you ever get your home made fabric impregnator to work?

About how many yards / square meter of fabric did each 6 hour session manage
to lay up?

And how much experience did your wetting out team have?

Thanks

There's one on Glenn Ashmore's site
No report on how it worked.

Jim



Jacques wrote:

I use that same low tech approach since years: wet the fabric on a
large piece of cardboard, roll it and unroll on the hull BUT, some
time ago, I saw pictures of a home made impregnator on the web and
lost the bookmark.
Does anybody know about that? I would like to try.

Jacques Mertens
http://bateau.com

"Evan Gatehouse" wrote in message ...
"Glenn Ashmore" wrote in message

I used the Tom Sawyer approach and got a bunch of volunteers. One
person mixing resin, two people wetting out and 3 people laying. We did
two layers of DB170 biax and one 6 oz. woven on my 45' hull in 6 hours.
After wetting out on a table made from a couple of sheets of melamine
we rolled the biax on 2" PVC pipe to carry it to the boat. The only
significant increase in cost was a couple of cases of beer when we
finished.

Glenn,

Did you ever get your home made fabric impregnator to work?

About how many yards / square meter of fabric did each 6 hour session manage
to lay up?

And how much experience did your wetting out team have?

Thanks