The gun had too many little areas that we needed to fix so we decided to cap it with a layer of 4 oz just for good protection. Since we sanded away a TON of extra resin we would actually end up with a board that was just as light as when we got her. The 4 oz layer provides a couple of advantages. One it seals the whole board in case we missed a little onion ring or pin hole and also it gives a layer to blast into to make the deck and bottom nice and flat.