I put mine over plywood sealed w/ fiberglass resin, no roughing needed, sticks fine. Use a trowel with small notches, once you start putting pressure on it the glue migrates well so do not put extra around the edges, you'll end up squeezing a bunch out the sides even w/o putting extra down. I used an old round seat pedestal to flatten it and press out any bubbles,use as much down force as you can press. It doesn't matter where you start, whichever is easiest, I started in the bow. The glue will take a long time to dry if it is too thick. Sent from my iPhone using Lake Ontario United mobile app