: I finished up on the glass work about 1pm and applied the fill coat
: about 6 or 7pm. I didn't check it but maybe once in between so
: not exactly sure on the tack free time. I do use scales to get
: the exact ratios if that's maybe your thinking. I'm questioning
: working at 85-80 degrees as a culprit. I have in the past
: preheated epoxy to 90 before working with it but never messed
: with the room temp. I'm wondering if at those temps I'm getting
: a much quicker kick.

: I do not use squeegees for any part of the process. I apply
: liberally with the roller working on about a 2'x2' area going
: over it enough to wet out the glass and even out the coverage. I
: try not to work it too much or too fast so as to avoid foaming.
: I also try not to apply to much pressure to the roller and work
: as wet and light as I can. When I stop with that area there is : more resin in the foam roller but I avoid trying to stretch it
: out by applying more pressure. If I was to squeegee after I
: don't think I would get much if any.

: I'm not apposed to going to a squeegee. I have done that. I just
: found rollers to be less messy and avoids the need to both apply
: and scape off, but that's maybe what I need to do. Most of my FG
: work has been with competition r/c gliders using carbon fiber
: and Kevlar. Very light layups. As in 12' wingspan gliders that
: weigh 54oz total with batteries and radios and can take 500lb
: loads. Maybe I've just gotten too used to near starvation
: layups.

I'm familiar with System Three regular all purpose resin and their slow, medium and fast hardeners.

When I use regular resin with slow hardener in 85˚+ shop, small, 6 oz. batches mixed, poured into a roller tray and rolled on with a West System roller cover it takes 10 to 12 hours for a tack free surface. This long slow set-up allows a very thorough wet-out and allows ANY air or bubbles to dissipate.

This seems much longer than the MAS with a slow hardener set-up time. So, that could be the first issue.

You said you didn't think you would have any excess resin to remove. Are you wetting-out the wood and glass at the same time?

If so, there is your problem. The glass may look wet-out but the wood could suck up more resin slowly over time , when you walk out the door starving the thread tops, which is what it looks like in your picture. And of course, you can't see it until you add fill coats.

I apply a seal coat to my bare wood and when this is tack free I wet-out the glass separately. This insures no struggle for resin between the wood and glass. I apply enough resin to give the glass a slight wet look. Next, I go over the wet-out glass gently but firmly with a squeegee made of milk carton plastic to REMOVE excess resin. This also forces resin into the glass and keep the glass from floating on excess resin. This is a very important step.

The white flecks appearing in your photo are definitely threads of glass that have not wet-out properly. I've seen this pattern most often with old glass cloth. It seems like the coating that makes the glass compatible with epoxy has been abraded or worn off somehow.

OR Another problem could be water damage or sweaty hand fouling the coating.

So, I think the potential problems are (1) resin set too fast, (2) starved glass /or (3) old or water contamination of the glass surface.

Epoxy starts to thicken the moment you mix in the hardener.

Are you are mixing batches larger than 6 oz.? This could be the problem.

Do you immediately pour the epoxy into a flat roller tray? If you don't the resin will thicken faster.

Do you roll on resin until the glass looks wet. Give the glass more than it needs because it takes a while to wet every twisted fiber in the cloth. Then squeegee off the excess for a mat consistent surface.

If you are not doing the things listed above, my best guess is the MAS with slow hardener set too fast at the higher temperature and you have starved the glass for resin.

Better luck next time.

Rob