'79 teardown and rebuild.

[SkunkBoat]

Originally Posted by 3 Squids

I read that HPDE board is the best to use.

HDPE is Starboard...$$$$you would need a 4x8 sheet.
PVC board is cheap.

Besides vinyl, you could use some cheap plywood and cover it with clear packing tape.

When you say "dam" you mean you're going to pour between outer transom and a temporary wall, then remove the wall after it sets and glass over? You need to be sure there are no leaks! (you saw my video).Be aware that the transom on a V20 is not flat across so if you use a flat template or dam, you will be thicker on the centerline. You going to have to think that thru...

I would probably glass a couple layers of skin to the template with excess tabs hanging over sides, pop it loose and glass that in place(keep your 1.5" thickness of transom). Then use the template as a brace for your pour.