My suggestion here would be to remove the rust, prime it, then put the diamond plate directly on top. Weld the diamond plate on around the perimeter. After this, Rhino Liner. Have it applied all over the top and down the sides and back in the toy hauler area. The primer will prevent rust until the diamond plate is down, welding it around the perimeter will seal it, and the Rhino Liner will both protect the seal and give you a good, strong rubbery surface. This will give you excellent traction up there as well. I'd suggest LineX, but that's a harder product with less traction than Rhino has.
There are also do-it-yourself truck bed liners you can use, but the professional stuff will give better results as their products are applied very hot while do-it-yourself is applied at room temperature. Eventually the do-it-yourself wears off.
|