Peel ply on non waxed vinylester

[Blue_Heron]

Originally Posted by FishStretcher

Thoughts that don't involve using epoxy, that is.

I haven't used vinylester resin (yet), but I have used peel ply on polyester resin. When the peel ply is wet out fully, there is no cure inhibited layer underneath.

As I understand it, the reason the surface of a polyester layup doesn't cure is that the MEKP, or some other component of the resin, evaporates out of the surface before the resin can harden. Presumably, the same applies to vinylester. The result is the sticky surface you get with unwaxed resin. The reason wax is added to resin or gelcoat is that, as the resin kicks, the wax is forced to the surface where it forms a barrier that keeps the good stuff from evaporating out. Peel ply can serve the same purpose and has the added advantage of leaving behind a surface with excellent tooth for a secondary bond.

For peel ply to work, you have to have enough resin to saturate it. I don't know if you'll get that with a thinned resin alone. If you weren't planning to add a layer of glass to the initial layup, I don't know if it will work. Why not do the penetrating resin and layup all at the same time? Working wet on wet is the best approach where practical.

And speaking as someone who has done layups in the tight quarters you're talking about, I would make sure you have good forced air ventilation in the bilge while you're working with styrene based products.

Dave