Greetings!
.
Finally found what to use for door panel backing that is thin &
won't absorb water. My convertible panels were past bad shape, but roughly $100 to $200 EACH, so I decided to make 'em.
. While discussing the dilemma with a Lowes employee, he suggested plastic. I bought a 4x8 sheet of FRP for about $15.
. FRP is a thin Fiberglass Re-enforced Plastic sold as a finish-type wall ' covering. Typically used in commercial apps like bathroom & kitchen walls where they frequently wash-down with steam or hot water, it's pebble-grain on 1 side & smooth on the back, plus quite flexible before install. (Mine was rolled & tied with string to fit thru the truck topper door.)
. FRP ADHESIVE is sold in caulk-gun tubes and gallons. Two mirrored pieces glued smooth-to-smooth should rigid enough for most stuff. It's easy to handle & work, but stay alert to what you are doing. Jagged plastic cuts nasty holes in skin!
. Next time, I'll use that PEEL & SEAL tech tip on the FRP.