When it comes to Riva bottom replacements, I've found that there are two main choices:
- Use a single 10-12 mm thick marine plywood sheet OR layering 3 x 3 mm plywood with epoxy.
- Laying some kind of glass fiber material on the bottom or not.
When it came to use glass fiber or not, I asked around and spent a lot of time on the web, and decided not to use glass fiber. My choice was to follow Dan Nelson's, one of the renowned restores in the US, procedure for West System bottom. You can find his write up here.
After two coats of clear epoxy, its time to fair in the bottom. At the bow there will some unevenness due to the plywood strips used, and its fairs in with West 410 fairing filler.
After curing, the bottom is sanded even.
First coat of West System epoxy, with 422 barrier coat additive.
4 coats with 422, laid with 8 hours of each coat. Once cured 48 hours, sanded
down ready for 2 coats of Epifanes 2-component epoxy primer.
