Basic Body Work question

[Scott Marzahl]

When doing fiberglass repairs, all the books say to build the area up with new glass and then grind down below the finished depth and use a filler to bring it back up. Why is this? Why wouldn't you just block sand the glass to the desired level?

[John H.]

Re: Basic Body Work question

Scott -

Because if you sand into the glass, you'll expose glass fibers on the surface; you have to finish a non-fibrous surface, thus the need for filler to seal the "hairs" down and provide a smooth, non-porous surface to prime, seal, and paint.

[Scott Marzahl]

Re: Basic Body Work question

Since this car had been sandblasted and made a mess of, I have begun blocking the old panels with 36 grit anyway and in this case I do plan on Gel Coating the entire car to seal all those hairs (I don't want to start a Gel Coat debate) I have read a few on this board. Is this a good plan?

[Ray C.]

Re: Basic Body Work question

Hi! Scott

I just completed the bodywork on my 65 and I think it came out great. If I understand your question, the information you are looking for is repairing cracks or replacement of panels. If you hollow grind the crack or where you join the panels, you can build this repair with multiple layers of glass matt and resin (woven fibers not screen) until you have a level surface. The build up process will strengthen the repair and prevent the seems from showing through your paint at a latter date. I would start this process on the bottom of the panel and then repeat on the exterior surface. You can use aluminum strips to secure the panels while you hollow grind and apply glass matt and resin. After the fiberglass has been repaired you can use a plastic filler to level the surface. The PPG factory rep. recommends that a catalyzed polly primer be used to seal any repaired surface. This product is easily applied and sanded and it fills minor imperfections.

I hope this helps!
If you have any more questions email me
Ray

[Larry Lena]

Re: Basic Body Work question

What type of filler is best to use lit or heavy weight?

[Larry Lena]

Re: Basic Body Work question *NM*