Thanks!
I'm new to epoxy too. How many layers/coats did you do to get that awesome shine? How was working on the vertical surfaces? Any tips?
To be honest, I'm sure there are better ways to do it, as I seem to have taken way more time than others (took few weeks to get it all done) and used way more epoxy (including the floor and the galley, 5 gallons) but here is what I did:
I followed Raka's epoxy manual - I did one thin layer (spread with a roller, than squeegee) before fiberglass to saturate the wood. Then put a 4oz fiberglass, one initial layer of epoxy, and then it took 2 more to fill in the weave.
I worked in sections (mostly due to time constraint) - one wall, the other wall, roof, hatch. I tried to keep <24h between first 3 layers since I didn't want to sand the first layer (the one before the fiberglass - I was worried I'll sand into stain) and the second (weave was visible, and I'm sure I would have ruined it).
After that I sanded layer 3 and 4 really well, since they come out rough - a bunch of drips, dips etc.
On one of the walls I tried to put one more layer to see if I can get this really perfect, but I found no additional benefit, so I kept to 4 thin layers for everything else.
It's still pretty cold here and I had to keep 3 heaters running in the garage to get it to 60F. Kind of run up my electric bill, but man, it felt good to have a warm garage for a change
FiberglassI went with 4oz cloth based on online advice - I didn't need strength and was mostly worried about wood checking. I think it's much easier - even when you get some voids during the application, the 4oz fabric stretches to accommodate any uneven application and you can press it in with a squeegee to fix the voids very easy.
From what I hear heavier weave may not be as forgiving.
I went with 50in width - I couldn't find the fiberglass wide enough to avoid seems, so I figured the best strategy was to align with the existing seams in 48" plywood (which anyway will be covered by the trim) - 50inch was just big enough to allow for a nice overlap on the seams.
ApplicationEach layer was applied with a roller to keep it thin, and I run over it with squeegee right after to remove the air bubbles (and there was a ton). Especially on a vertical I tried to keep the layers very thin - it felt like I'm throwing away a lot of epoxy though - everything that stayed on squeegee was turning into this cloudy white substance, so I had to discard any epoxy which stayed on the squeegee after each pass. It easily felt like I'm throwing away over 20% of what I just applied.
It helped to mix small batches - I started with 6 oz per batch, then moved to 9oz. Anything larger than that and the epoxy turned cloudy before I could finish applying. I also found I had to discard the roller every 1-2 batches which felt pretty wasteful (I found some cheap rollers on the web, but still). I still don't quite understand if there is a way to avoid this - the epoxy on the roller would start setting and it would cause the subsequent batch to cloud up when I tried to reuse it for longer.
Despite thin layers, this stuff runs like crazy - I'd keep checking back on it every 30 minutes, and frequently things were fine for a few hours, then I'd come back the next day and find a bunch of large drips which developed overnight. Good news is it can all be sanded pretty well before varnish.
SandingI wet-sanded everything - I started using a block, but it was really slow. Against all the good advice I moved to an electric orbital sander at lowest rpm and used a rag to keep the sandpaper wet, hoping that GFCI will kick in in case I get too much water on it... It ended up being just fine, no electric shocks to report and I didn't trip GFCI either. Even with orbital sander and grit 80, doing all the layers took a while and it's a messy process.
Wear a respirator - even with wet sanding this stuff gets everywhere.
VarnishAfter sanding the last layer as well as I could, I applied 3 layers of spar urethane, sanding lightly in between with 240 grit. It took at least 24h before each layer was dried enough to sand, and even that felt like a stretch.