ImBatman

I have started the body prep for my '71 and have read and purchased lots of material on how to sand and fix various problems with fiberglass. Here is my issue and most books don't seem to cover repairs this small. I have a hole about twice the size of a BB on the rear quarter panel upper part. How do I fix this? Is it neccessary to use fiberglass mat here or just resin or some other type of filler?

Rolling Thunder

I'm by no means an expert but here's my method: Filling holes such as trim bolt holes could be done with filler, but stand the chance of showing up later when the filler shrinks. If it is a clean round hole, I use a countersink to give it a taper, then tightly role a strip of fg mat, saturate it with resin and stick it through the hole. The back side will swell out to lock it from coming out, and the outside will conform to the taper. When it dries, just sand off the part that sticks out.

Good luck,
Dave

LemansBlue68

Bevel the edges of the hole back at a bit of an angle (like 45 degrees) to give the filler some area to bond to. Use long strand fiberglass filler (USC Long 'n Strong) to fill the hole and bring the level flush with the rest of the panel. Sand the fiberglass filler flush while its still a bit soft otherwise its a bear to sand when it gets rock hard. Use body filler over top if you have any slight depressions or air bubbles in the repair and sand flush again. The long strand 'glass won't shrink or swell and its strong and waterproof. You should only use body "filler" in thin layers.

Easy Mike

Can you reach the underside of the hole? I would lay up a patch (mat) on the underside. One course will work for the underside. I would then dish grind the hole from the top and lay up a three course mat patch. Finish the surface and prep for paint.
:)

Paul 75 L82

The Evercoat Plasticworks, Corvette panel Adhesive works good for your Bondo material. Sands every good. I think if you bevel your hole you can use this material for the complete fix.