plywood choices for floor and transom

[spareparts]

one other trick, if you have to reinforce something on the back side, take a piece of pvc, cut it in half down the middle, lay on it the piece your glassing after a layer or two, lay the next layer(or two) over the pvc, it will create a chamber that will make it stiffer. I know some guys that build racing sailboats(yes I used to race), they have a rubber oval shape hose they lay inside the molds, they glass over them, then after it kicks, they pull real hard, the hose gets smaller from pulling it, and it slides out, leaving only the glass in a shape that makes it stiffer.