From the West System site:
879 Release Fabric
Economical Release Fabric is a tough, finely woven nylon fabric treated with
a release agent. It is used to separate the absorber, breather and vacuum bag
from the laminate in vacuum bagging operations. Excess epoxy bleeds through
and is peeled from the cured laminate along with the Release Fabric. It's
also used in hand lay-up applications to allow more squeegee pressure and
protect the lay-up from contamination. Peels easily and leaves a smooth
textured surface, ready for bonding or finishing. Not recommended for
post-cure temperatures over 120°F (49°C). 60" wide x 2 yd., 10 yd. rolls. 60"
x 9" sheet.

Matt Colie wrote:

Pete,

Peel-ply is usually used for vac-bag or other clamping systems. If you
don't have to fight to hold the material in place - don't. The peel-ply
material is also heavily loaded with a silicon based relase agent. I
would be afraid of having that between lay-ups and it is not easy to
clean off completely. The amine blush, on the other hand, washes right
off. The West/Gougeon book cover this well.

You should be able to create a good surface without anything other than
a squeegee. If you want a better surface for final surface, get some
fine weave 1-2oz cloth and use that as the last layer. If that is not
good enough, put a finish holder of mylar or polyethylene and comb out
the bubbles with a squeegee.

Good Luck
Matt Colie

pete wrote:
On Mon, 06 Sep 2004 14:53:34 -0400, Matt Colie
wrote:


Pete,

I guess I don't undestand what you are trying to do.

Are you using the peel-ply to make surface the for future lay-up?

If so - Why?

Are you working overhead?


I'm not working overhead but on an inverted hull - sorry sometimes I
don't make myself very clear.
I have laid six layers of glass cloth over the area where the keel
will be for reinforcement, after that I will be covering that and the
rest of the hull with more cloth. I am used peel ply to leave a good
surface for the following layer of cloth and to avoid any amine
blush. After the next layers I want to use peel ply for the same
reasons, for the fairing compound. ie it will not need sanding.

Pete

Matt Colie
pete wrote:

Help me please guys,
I'm just about to lay up a hull with two layers of uni-directional
cloth and epoxy and I want to lay peel ply over it.
My problem is that I have very little experience with laminating,
confined only to repairing the occaisionally holed dinghy after being
too stupid.
I have just done the initial layup which called for six layers of
woven cloth in the keel area, in preparation for the full hull layup.
I didn't want to try to do the entire layup in one go because I would
not have enough help (I think) or experience to do it all. I would
also have a relatively small area to put right if I botched it up.
That was a good idea as it turned out.

So I laid up the cloth and epoxy, and laid on the peel ply. It looked
really nice until I came back a day later and saw that it had
transformed itself from a nice smooth oval of cloth to a picture of
the North Sea on a bad day. More wrinkles than an elephants trunk.

Which means more work sanding I suppose, but what bothers me is that I
tried REALLY hard not to stretch the peel ply as I brushed it smooth,
but I guess I must have done. I need to do the full layup on the hull
now, but I'm worried that I'll botch it again and it's gonna look
really bad.

Any tips from out there? Can you not brush the damn stuff at all? I
did put more epoxy on than I needed in fear of not having enough.
Would that have had an effect? If so, When do you know that it's just
right?

Thanks in advance,

Pete