I use nothing but Deft sanding lacquer to glass with these days.I gave un using epoxy and resin years ago after a friend put me onto the deft. It's not water based though and stinks. The deft gasses off and about 80% of the weight is gone when it gasses off and I use 1/2 ounce or 3/4 to glass with. On the bare frame I slather on two coats of the deft then sand, this just keeps from wasting the sealer, if you don't seal first the stuff goes into the wood and it doesn't stick as well. I lay on the glass with the first coat then in about an hour I give it another coat. You can use the same brush for about two days, just sticking the brush into the deft and letting it sit for a few minutes it softens the dried deft on the brush. I give it a third coat then sand off the extra glass then give the plane another coat or two. Final coat I mix a batch of deft 50/50 with talc or baby powder. Slather it on then when it's set up, the next day, I finish sand. This removes almost all of the baby powder and added weight. Finished. Smooth as silk!! Before painting I give the plane a wipe down with a rag with lacquer thinner or what ever I use as a paint thinner.
Once I gave the deft a try I haven't used anything else for glassing. So easy to Sand and comes out so smooth. Cheap to use too. Other then the stink I have no complaints using it.