i have a plastic drop in bedliner and the previous owner cut huge holes for the clamps for his fiberglass cap. i dont have a cap or cover on the bed and i dont plan on putting one on either. How can i patch these holes so water willl not get into them?

 

I guess you could fiberglass over them, or if you have a plastic welder and some similar plastic, weld a patch over the holes. Could also rivet a piece of sheetmetal over the hole and seal it with silicone. If it were me I would use the holes as an excuse to get rid of the plastic bedliner and have a Rhino or Linex sprayed in instead.

 

tape some cardboard on the underside covering the hole.
cut some fiberglass matting to fit the hole and resin over it.
sand smooth and paint.

 

thanks