Newbie with a Starcraft restoration question

Ok, I have a 1973 Starcraft SS deep v-hull aluminum boat 16' and over the winter I plan on making some new cushions for the bow. I pulled the old ones which are moldy and the vinyl is bad. I am going to use the old ones as my template to cut new wood and put some foam and marine grade vinyl. When I replace the floor in the spring, I am going to use marine grade plywood, but do I need to use that wood for the seat cushions or can I just use regular plywood? If I use regular plywood, should this be sealed with epoxy or something? Any suggestions on supplies for the cushions? I found an online source for fabric and they have marine vinyl for about thirteen dollars a yard and I would need four yards. What about the foam? Should this be outdoor foam, like one might use for outdoor furniture. There is a foam product that does not absorb water but would cost about eighty bucks to do all three cushions. Has anyone ever made new cushions?

Re: Newbie with a Starcraft restoration question

I don't know anything about your upholstery questions so I'll stay outta that.

Marine grade plywood, contrary to popular belief, is NOT treated against rot. It is simply a better quality plywood with varying improvements over standard exterior grade which can include more plys, plys laid on a diagonal in addition to just perpendicular, better quality glue, etc etc. It should still be sealed to prevent rot. Which method you chose depends on how long you want it to last and how much you want to spend. From best to least:

- Fiberglass with either poly or epoxy resin
- epoxy resin alone (do not use poly resin alone. it is worthless without glass)
- marine spar varnish
- quality porch and floor paint
- crayola markers you steal from your kid
- Thompson's Water Seal

On my boat I used exterior plywood for the deck sealed with epoxy resin. I used exterior plywood for all my above deck stuff like side panels and bow deck sealed with porch and floor paint. Arauco exterior plywood from Lowes (and I think Menards) is an excellent alternative to marine grade and about half the cost.