Originally Posted by RSchleder
YES, you will need a topcoat/gelcoat. The fiberglass you will ad to the inside of the trailer, after you clean the general inside area with a proper solvent, will simply provide, after it sets up, the strong backing for a thin gel-coat layer on the outside of the trailer that can be sanded and painted.
The fiberglas resin will be thin and needs to be painter onto the fiberglass to saturate the glass. Also paint
a thin layer onto the cleaned area on the inside of the trailer where the saturated glass will be layered.
You need the thicker gel-coat to be the final outside layer because you cannot sand resin impregnated fiberglass cloth smooth as it wii continue to expose fibers during sanding. Gel-coat becomes the final, smooth surface you will sand using various grit sand paper until it's as smooth as the rest of the exterior and the contour matches the rest of the area around it. If done slowly and properly, the repair will be strong and essentially invisible when painted. Good luck!!
Thank you for the suggestions. Do you mean "inside area" as in the back of the fiberglass? Or do you mean the exposed area where there are the dents? I have only seen video instructions on how to add fiberglass to the backside. I have also watched videos where a film is taped to the front, gelcoat is added via back, and THEN lastly goes on the fiberglass sheets. But I don't have access to the back.