Have you tried short bristle rollers. Even the thinnest foam roller can act like bellows, forcing air into the resin. Bristle type rollers with short, fine bristles cause fewer bubbles and can move more resin.

> Because you could detect that the roller path was affecting the
> wetting out, I would suspect that the rollers were causing the problem.
> I think that the first epoxy you mixed was curing on the roller. As
> you rolled with the dry parts of the roller, the cured epoxy was being
> rolled into the cloth and not wetting it well.

> There are 2 distinct types of yellow rollers. One works well
> with epoxy. The other seems to react with the epoxy (the foam rolls
> off of the inner shell).

> I agree with the others heat is a bad thing to apply to epoxy
> unless you know what you are doing.