I've done all the fairing that is needed to paint the cabin top inside gunwale to gunwale and it took less than 500gms of resin.
The foam is so straight I just had to fair in the tapes and the companionway. I was expecting have to use a lot more resin but my system of taping has worked a treat.
All 100mm tapes have 150mm of peel ply over them. When the peel ply was removed I went over the edge of the tapes with a scraper with sharp tungsten blade feathering just the ends. Put the faiing compound on with a spring steel fairing knife and scraped most of it off at the same time. This just leaves the hollows filled. Once cured I went over the tapes again with the tungsten bladed scraper, you can see the shavings as I haven't vacuumed yet.I may light sand so the paint has a key but that is all. I can currently see where the tapes are but I can't feel them. Can't feel so once painted won't see.
If the weather is OK tomorrow I'll start painting.
Here are pics.
Looking aft in the cabin.
If this thing ever flips I want the top seat.