It sounds like the resin is not the problem. It the way the glass and
resin were applied. When you put glass on a model the purpose is to add
strength and second to give a smooth base for paint.
The first rule when you apply glass with epoxy is don't use any more resin
than is needed to stick the glass to the surface. The glass provides the
strength and the extra resin is just extra weight and actually reduces the
strength of the glass cloth.
The best method is to wet the surface then apply the cloth to the wet
surface. Then add more resin only where there is a dry place or a air
bubble in a corner. Then use a paper towel and blot off all the excess
resin. The surface should look dull, you should be able to see the weave
of the fabric under a strong light.
After the resin cures, sand off any rough edges and the second coat of
resin is added to give a smooth surface. To do this add a light weight
easy to sand filler to the epoxy like WEST SYSTEM MICROLIGHT. Mix it to a
peanut butter thickness and spread a thin layer on the model. When it
cures the surface will be rough, but it sands very easy and the result is a
perfect surface to paint with a minimum of added weight.
Matt Gewain
Composite Structures Technology
At 11:22 AM 9/3/99 -0700, Steve Kerrin wrote:
>I've been rebuilding an old 60" sloper and
>have run into a problem in glassing the fuse.
>I know a vast number of the list members are
>into composites and glassing so here is my
>question:
>
>I glassed the fuselage with a layer of 3/4 oz
>
>glass according to the methods published
>recently in MAN as well as other articles by
>Jim Ryan and others.
>
>No problem so far. Everything cured nicely, I
>
>gave it a light sanding, wiped it down with
>methanol and applied a second coat of resin
>thinned slightly with methanol (I'm using
>Jeffco 1314/3102 as it is on the shelf
>locally). Everything flowed out nicely so I
>hung it up to cure. Next morning, I checked
>it and found that it had beaded-up during
>curing. Not droopily beads, but long soft
>ridges. Lots of sanding required....UGH!
>
>I ran a few experiments on small test
>sections with thinned and unthinned resin,
>with similar results. I understand that some
>finishing resins contain a bit of wax which
>could cause such behavior, but this one does
>not (according to the supplier).
>
>Before I go purchase another kind of resin
>(seems the most obvious thing to try next)
>are there any ideas from the vast knowledge
>pool out
>there?
>
>TIA
>Steve Kerrin
>Escondido, CA
>
>
>
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