Other factors could be an issue. Things like trapped
: bubbles or wrinkles. So, am I missing anything?

: Ted

Yes.

The cloth weave is made up of twisted strands of glass fibers which trap air. And where strands cross in the cloth weave, air bubbles get trapped. The trick is to make your resin displace this air and totally wet-out the glass strands.

When you pour resin on glass cloth the resin will go through the pour site weave and raise the glass, because it can go through the open weave faster than it can wet-out the trapped air in the cloth. Then the resin will continue to raise air entrapped glass on top the pour as the flow spreads underneath the glass cloth.

If you have glass floating on resin and you work it out with a squeegee, it is very easy to create a micro foam as a wave of cloth and resin in front of the squeegee edge gets smashed through the cloth weave like waves on a rock shore. This micro foam is very hard to dissipate.

Resin thickens from the moment you add and mix the hardener.

If you pour resin onto glass and work a large area, like it is oh so tempting to do on the inside of the hull, you can very easily wet-out the glass but have excess resin trapped under it. This is because the resin has thickened to the point where it will not pass back through the weave when you try to squeegee out the excess.

I never wet-out more than half a hull or deck before I go back and squeegee off the excess.

Resin thickens from the moment you add the hardener. This is why I stress having a warm shop, slow hardener, small batches, roll on and squeegee off excess. This applies the thinnest most even coat, wets-out the glass completely, and removes excess resin and keeps the glass in contact with the boat. I bet I get close to a vacuum bagged wet-out.

On my first stripper, I had two friends help mix and apply resin to the glass wet-out. I had serious floater wrinkles in the glass. We didn't know about squeegeeing off the cloth to remove excess resin.

I'll never forget that. I appreciated my friends' help, but I've done my glassing alone ever since.

If you start with a small batch of warm, thin, resin and roll it onto warm wood and glass, it will remain as thin as possible and displace all the entrapped air in the strands and weave. Rolling carefully, applies only enough resin to wet the glass and the thin resin, slow hardener and warm temperatures keep the resin thin for a long time, which I have found allows even micro foam to dissipate.

If you can see a silver fleck to your glass from a certain angle as you look at it in the sun, you have not wet-out the glass completely. That silver fleck is trapped air. I see this most often on stem and hull/deck seams on people's boats because even though they used thin resin for their hull/deck wet-out, they tried a faster thicker resin on their seams glass.

Been there, done that.

Rob

Perhaps you can do the same thing with one of the special thin wet-out resins at lower temperatures, I don't know.