Epoxy Transparency Problem
 

I'm having trouble covering some plywood with fiberglass cloth. The problem
is that I want to be able to see the wood under the cloth, but the cloth
just doesn't seem to want to get "transparent". I've covered plywood before
using this method, including a wooden kayak, and it usually comes out great.
I've been able to sheath the foredeck of the boat successfully, and the
fiberglass "disappears" into the epoxy resin, but for some reason all of a
sudden I'm having problems. It gets about 90% transparent, but stays a
little milky. I've made sure that I lay the cloth onto a wet piece of
plywood, and that I force more epoxy into the weave, but still it looks only
partially transparent. Ideas?

Thanks,
Bill L.

Epoxy Transparency Problem
 

On Tue, 29 May 2007 00:05:37 GMT, "William Longyard"
wrote:

I'm having trouble covering some plywood with fiberglass cloth. The problem
is that I want to be able to see the wood under the cloth, but the cloth
just doesn't seem to want to get "transparent". I've covered plywood before
using this method, including a wooden kayak, and it usually comes out great.
I've been able to sheath the foredeck of the boat successfully, and the
fiberglass "disappears" into the epoxy resin, but for some reason all of a
sudden I'm having problems. It gets about 90% transparent, but stays a
little milky. I've made sure that I lay the cloth onto a wet piece of
plywood, and that I force more epoxy into the weave, but still it looks only
partially transparent. Ideas?

Thanks,
Bill L.

Off the top guesses:
fiberglass prepared for polyester resin
or
humid day.
??

Brian W

Epoxy Transparency Problem
 

Hi Brian,
It's not humidity, so maybe the wrong cloth? I'll look into that.

Thanks,
Bill Longyard

"Brian Whatcott" wrote in message
...
On Tue, 29 May 2007 00:05:37 GMT, "William Longyard"
wrote:

I'm having trouble covering some plywood with fiberglass cloth. The
problem
is that I want to be able to see the wood under the cloth, but the cloth
just doesn't seem to want to get "transparent". I've covered plywood
before
using this method, including a wooden kayak, and it usually comes out
great.
I've been able to sheath the foredeck of the boat successfully, and the
fiberglass "disappears" into the epoxy resin, but for some reason all of a
sudden I'm having problems. It gets about 90% transparent, but stays a
little milky. I've made sure that I lay the cloth onto a wet piece of
plywood, and that I force more epoxy into the weave, but still it looks
only
partially transparent. Ideas?

Thanks,
Bill L.

Off the top guesses:
fiberglass prepared for polyester resin
or
humid day.
??

Brian W

Epoxy Transparency Problem
 

William Longyard wrote:

Hi Brian,
It's not humidity, so maybe the wrong cloth? I'll look into that.

I'm with Brian, check the glass.

Try a piece on some scrap. See what happens.

Lew

Epoxy Transparency Problem
 

On Tue, 29 May 2007 00:05:37 GMT, "William Longyard"
wrote:

I'm having trouble covering some plywood with fiberglass cloth. The problem
is that I want to be able to see the wood under the cloth, but the cloth
just doesn't seem to want to get "transparent". I've covered plywood before
using this method, including a wooden kayak, and it usually comes out great.
I've been able to sheath the foredeck of the boat successfully, and the
fiberglass "disappears" into the epoxy resin, but for some reason all of a
sudden I'm having problems. It gets about 90% transparent, but stays a
little milky. I've made sure that I lay the cloth onto a wet piece of
plywood, and that I force more epoxy into the weave, but still it looks only
partially transparent. Ideas?

Thanks,
Bill L.


If you using epoxy and the cloth doesn't disappear then it is likely
that you have cloth made for use with polyester.

Bruce in Bangkok
(brucepaigeatgmaildotcom)

--
Posted via a free Usenet account from http://www.teranews.com

Epoxy Transparency Problem
 

Glass heavier than 6-8 oz. will not go clear in epoxy. If you need a
heavier layup for structural reasons, a clear finish is out.
Glass cloth has a 'sizing' treatment that is sometimes specific to a
particular type of resin. Ask your vendor if that glass is intended for use
with epoxy.

"William Longyard" wrote in message
link.net...
I'm having trouble covering some plywood with fiberglass cloth. The
problem
is that I want to be able to see the wood under the cloth, but the cloth
just doesn't seem to want to get "transparent". I've covered plywood
before
using this method, including a wooden kayak, and it usually comes out
great.
I've been able to sheath the foredeck of the boat successfully, and the
fiberglass "disappears" into the epoxy resin, but for some reason all of a
sudden I'm having problems. It gets about 90% transparent, but stays a
little milky. I've made sure that I lay the cloth onto a wet piece of
plywood, and that I force more epoxy into the weave, but still it looks
only
partially transparent. Ideas?

Thanks,
Bill L.

Epoxy Transparency Problem
 

"Jim Conlin" writes:

Glass heavier than 6-8 oz. will not go clear in epoxy. If you need a
heavier layup for structural reasons, a clear finish is out.
Glass cloth has a 'sizing' treatment that is sometimes specific to a
particular type of resin. Ask your vendor if that glass is intended for use
with epoxy.

I don't know what 6-8 oz is in real units but here is a 21 year
old boat that has some 360 g/sqm of UDWR glass in epoxy on each
side of the Western Red Cedar. Looks OK to me but your mileage
may vary.

http://hem.bredband.net/b262106/Boat/juguete.html
and
http://hem.bredband.net/b262106/Boat/build.html

I think the OP's problem is contaminated glass.

--
Martin Schöön "Problems worthy of attack
show their worth by hitting back."
Piet Hein

Epoxy Transparency Problem
 

360 g/m^2 is about 10.6 oz/yd^2. You did well with it. Nice work.
I agree that the more probable problem is contamination /sizing.

"Martin Schöön" wrote in message
...
"Jim Conlin" writes:

Glass heavier than 6-8 oz. will not go clear in epoxy. If you need a
heavier layup for structural reasons, a clear finish is out.
Glass cloth has a 'sizing' treatment that is sometimes specific to a
particular type of resin. Ask your vendor if that glass is intended for
use
with epoxy.

I don't know what 6-8 oz is in real units but here is a 21 year
old boat that has some 360 g/sqm of UDWR glass in epoxy on each
side of the Western Red Cedar. Looks OK to me but your mileage
may vary.

http://hem.bredband.net/b262106/Boat/juguete.html
and
http://hem.bredband.net/b262106/Boat/build.html

I think the OP's problem is contaminated glass.

--
Martin Schöön "Problems worthy of attack
show their worth by hitting back."
Piet Hein

Epoxy Transparency Problem
 

William Longyard wrote:
I'm having trouble covering some plywood with fiberglass cloth. The problem
is that I want to be able to see the wood under the cloth, but the cloth
just doesn't seem to want to get "transparent". I've covered plywood before
using this method, including a wooden kayak, and it usually comes out great.
I've been able to sheath the foredeck of the boat successfully, and the
fiberglass "disappears" into the epoxy resin, but for some reason all of a
sudden I'm having problems. It gets about 90% transparent, but stays a
little milky. I've made sure that I lay the cloth onto a wet piece of
plywood, and that I force more epoxy into the weave, but still it looks only
partially transparent. Ideas?

Thanks,
Bill L.


How can you tell if it is prepared for polyester or not? Make up a
sample and try to rip if off the substrate?
I ran into an adhesion problem a while ago and I'm now wondering if the
glass I got was prepared for polyester and I didn't know it. After
laminating two layers of 6 oz fabric on my cockpit sole, I was able to
tear the epoxy up with me hands. I was also able to rip the two layers
of glass apart. Maybe this is what happened. Hmm..

Epoxy Transparency Problem
 

""Martin Schöön"" wrote in message
...
"Jim Conlin" writes:

Glass heavier than 6-8 oz. will not go clear in epoxy.



I don't know what 6-8 oz is in real units but here is a 21 year
old boat that has some 360 g/sqm of UDWR glass in epoxy on each
side of the Western Red Cedar. Looks OK to me but your mileage
may vary.

I think the OP's problem is contaminated glass.

--
Martin Schöön

33 g/sg m is about 1 oz.
Hence 360g/sqm is about 11 oz cloth.

Peter HK

Epoxy Transparency Problem
 

William Longyard wrote:

I'm having trouble covering some plywood with fiberglass cloth. The problem
is that I want to be able to see the wood under the cloth, but the cloth
just doesn't seem to want to get "transparent". I've covered plywood before
using this method, including a wooden kayak, and it usually comes out great.
I've been able to sheath the foredeck of the boat successfully, and the
fiberglass "disappears" into the epoxy resin, but for some reason all of a
sudden I'm having problems. It gets about 90% transparent, but stays a
little milky. I've made sure that I lay the cloth onto a wet piece of
plywood, and that I force more epoxy into the weave, but still it looks only
partially transparent. Ideas?

Thanks,
Bill L.




send me a little piece of the cloth and I will try it with my epoxy on
some wood and send it back to you.
- that should provide some clues......


paul oman
48 wildwood drive
pittsfield NH 03263

Epoxy Transparency Problem
 

send me a little piece of the cloth and I will try it with my epoxy on
some wood and send it back to you.
- that should provide some clues......
Paul, that's exactly what I did and I could rip the cloth right off the
wood. I also tried it with a piece of West Biax and could not rip it off
the wood so I suspected the cloth the problem. I threw the cloth away
and bought new cloth.
I'd love to send you a piece of the new cloth I have so I don't have to
do this again.
Thanks,
Dan

Epoxy Transparency Problem
 

Dan wrote:



send me a little piece of the cloth and I will try it with my epoxy
on some wood and send it back to you.
- that should provide some clues......

Paul, that's exactly what I did and I could rip the cloth right off
the wood. I also tried it with a piece of West Biax and could not rip
it off the wood so I suspected the cloth the problem. I threw the
cloth away and bought new cloth.
I'd love to send you a piece of the new cloth I have so I don't have
to do this again.
Thanks,
Dan

Time needed to get good adhesion is an unrelated issue more tied with
curing times. WEST epoxies seem to develop good adhesion within a day,
our epoxies need 2 days. But WEST has a shorter potlife and bigger
exotherm so I suspect it is further down the curing curve after 12 or 24
hours than our epoxy. Note that epoxies really take about a week for
full cure.

Again, I would be pleased to coat your cloth with our BASIC NO BLUSH and
send it back to you - send to 48 wildwood, pittsfield NH 03263