I took several hours today and washed, then sanded the new glass set in epoxy. This took about an hour, altogether. I allowed an interval of 30-40 minutes for the boat to dry thoroughly before sanding. When West System epoxy cures it leaves a wax-like coating on top. This has to be washed off. I used a little bit of laundry detergent in about a gallon of water and a scrub brush to apply. I washed the entire surface of new epoxy with the brush, then followed up with a rag in soapy water. Rinsed with clean water, and wiped down with the wrung-out rag.
Sanding came next, as subsequent coats of new epoxy bind best to the surface if it has been abraded. My random 5″ orbital sander with 60 grit disc did a great job. I used three discs. I confirmed that the shop vac is most effective at removing dust when the intake is connected to the sander, not the exhaust. Good thing I was wearing my respirator. Here are few photos showing how well the weave of the glass is filled.
Time for second (and final) coat of epoxy resin. This application went much faster than the first, as there was no fabric to saturate. I used a three-inch foam roller, and again just poured the resin on the surface, then rolled it out. I made up 4 batches of resin (4 pumps each of resin and catalyst). The coating was done in fifteen minutes. When I checked it several hours later, it was completely cured.
As I mentioned after applying glass to the bottom, I’m very pleased with the rigidity of the hull, especially at the transoms. There is a very noticeable improvement. I’m anticipating an even greater improvement when I glass the inside of the transoms. As I had hoped, the glass and resin have served to fill much of the unfairness of the grinder/paint removal. The finish is a good bit smoother and fairer than before.
Had I been really smart, I would have masked the top sides with tape and paper and caught the resin drips, saving myself a bunch of sanding. Oh well. . . Next time, I’ll remember. Maybe.