I've used every technique and product imaginable for glassing. Here are my opinions:

Waterbased polyurethane tends to warp sheeting up to 3/16 of an inch thick. It doesn't fill the weave well in the cloth, and I won't use it again. It is easy because there is no mixing, and cleans up with water. It dries in a few hours, so it is possible to put on several coats a day.

Polyurethane finishing resin is good, sands better than most epoxy resin, and in my opinion, smells good. The only problem is if you use wood filler to fill dents and dings, the resin may not cure. It also doesn't like to cure over most 5 and 30 minute epoxies.

Finishing epoxy such as the West systems, EZ lam and the Pacer Z-poxy finishing resins all work well. They will cure over everything, but will gum up the sandpaper while sanding. Except for the Z-poxy, you should wait several days or up to a week before finish sanding the top coat.

I use to weigh each project before and after the application of the finish resins, and I always seem to have the polyurethane finish resin end up the lightest per square inch.

Email me privately if you have specific questions about application techniques.

Moot