by afreegreek » Wed Jan 27, 2010 7:21 pm
these type of products are designed to be applied over paint or primer on metal. getting it to stick to wood is more of a problem. the wood must be extremely dry and stay that way or it will bubble and peel off. a coat of epoxy or epoxy sealer such as S-1 will give you a better surface for the bed-liner product to stick to and make moisture content of the wood less of an issue. the epoxy will bite into the wood and the bed-liner will bite into the epoxy. with most epoxy products you will have to sand or wash off the amine blush before applying the bed-liner. washing will do but since most epoxies will cure to a glassy smooth finish, sanding will give you better adhesion. just a quick rub to tooth the surface is all you need. grey, green, or red scotch-brite pads or 80, 100, or 120 paper.
depending on the product and how thick a coating you're going to apply will make a difference in what grit you can get away with. 80 grit is the best but may show through the final surface. it would be best to do a test sample to see.
a lot of people assume paint type products will fill and level defects in the surface but 99 times out of 100 they don't and actually magnify the defects. since this is the show surface it would be best to make sure you have a smooth base to apply to and the tooth you put in is not too coarse.
***I should also add that most bed-liner products are a BEAR to remove should you change your mind later. most will sand off but they plug paper like there's no tomorrow. some of the more rubbery ones just laugh at paper and using a heat gun and scraper is the only way to get it off. a long and nasty job at best..