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I have a 69 corvette. I want to repaint it to the original Green Color. The last guy who painted it put left a lot of pits on the back deck and various other places. I assume he sanded the pits into the fiberglass. What is the best and easiest way to fix these when I repaint it?
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Re: C3 Body work
Brian, what's your definition of a pit... what diameter, what depth?
When I think of a pit in fiberglass, it's more of a small diameter (1/8"-1/2") rough, sharp-sided gouge inflicted by some kind of sharp object. It's impossible to get that configuration by sanding; the closest you'll come is a nice smooth dip about 3/4"-1 1/2" in diameter. It's determined by the diameter of your finger, the need to move the sandpaper to make it work, and the lack of perfect flexibility in the sandpaper. I suppose he could have used a small conical grinding stone in a Dremel tool, but that makes no sense.
If the pits are deep, you could probably partially fill them with resin and mat, but that may be more touble than it's worth if there are no cracks. Utimately, you will have to use body filler for the final body contour anyway. Working cured resin and mat to body contour is possible, but it is hard work, requiring more time and patience than most are willing to invest in anything. Consequently, even if someone tries to work the fiberglass, they end up with a less satisfactory repair than just using the filler in the first place.
There aren't four of them in a rectanular pattern is there? Two on each side of the deck? It could be poor repairs of holes left from a previously installed luggage rack. If that is the case, you may find the previous repair was done with bondo...you'll need to grind it all off, taper grind around the hole, and laminate resin and mat inside and out to fill the holes. -
Re: C3 Body work
Brian, what's your definition of a pit... what diameter, what depth?
When I think of a pit in fiberglass, it's more of a small diameter (1/8"-1/2") rough, sharp-sided gouge inflicted by some kind of sharp object. It's impossible to get that configuration by sanding; the closest you'll come is a nice smooth dip about 3/4"-1 1/2" in diameter. It's determined by the diameter of your finger, the need to move the sandpaper to make it work, and the lack of perfect flexibility in the sandpaper. I suppose he could have used a small conical grinding stone in a Dremel tool, but that makes no sense.
If the pits are deep, you could probably partially fill them with resin and mat, but that may be more touble than it's worth if there are no cracks. Utimately, you will have to use body filler for the final body contour anyway. Working cured resin and mat to body contour is possible, but it is hard work, requiring more time and patience than most are willing to invest in anything. Consequently, even if someone tries to work the fiberglass, they end up with a less satisfactory repair than just using the filler in the first place.
There aren't four of them in a rectanular pattern is there? Two on each side of the deck? It could be poor repairs of holes left from a previously installed luggage rack. If that is the case, you may find the previous repair was done with bondo...you'll need to grind it all off, taper grind around the hole, and laminate resin and mat inside and out to fill the holes.Comment
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Re: C3 Body work
There are about ten of them. They are all over the rear deck. I do not think it was a luggage rack. There are a few in other places also. They kinda look like dings you get in a metal car. They are maybe 1/2 inch long, not very deep, but you can feel them and see them. Thanks.Comment
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Re: C3 Body work
There are about ten of them. They are all over the rear deck. I do not think it was a luggage rack. There are a few in other places also. They kinda look like dings you get in a metal car. They are maybe 1/2 inch long, not very deep, but you can feel them and see them. Thanks.Comment
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Re: C3 Body work
Brian:
Just to add to Chucks thought. There are two styles of luggage racks that I have seen used on the '68 thru 72 cars, one of course was not proper for the time period. One rack uses 6 mounting holes, the other uses 8 holes.Comment
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Re: C3 Body work
Brian:
Just to add to Chucks thought. There are two styles of luggage racks that I have seen used on the '68 thru 72 cars, one of course was not proper for the time period. One rack uses 6 mounting holes, the other uses 8 holes.Comment
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Re: C3 Body work
If you strip the car to bare fiberglass for painting, use premium fiberglass-safe stripper (3-4 gallons) to take off the color and sealer coats, then wet sand off the red oxide primer using 240 grit sandpaper. Work a small area (2-3 sq ft) all the way through from stripper to sanding off the primer, and repeat until done. If the car has already been stripped once, then the bottom primer coat will not necessarily be red oxide like the factory.
Soft rubber sanding pads will perserve more of your fiberglass character (if it hasn't already been blocked), but use a hard rubber sanding block on the rear deck (wherever you have dings)...you will see every ding clearly because it will be hard to get the red primer out of the low spots. To clean out the dips, you will probably have to sand them with your finger. Mark them or record the dings some way for future reference.
Roughen the area to be filled with 80 grit sandpaper(dry), then apply a skim coat of quality filler directly over the low spot. Don't let your 80 grit sandscratches go beyond where you are filling, or they can cause you trouble later. Try to build your filler just slightly above the deck contour, and then block it flat.
If you're a perfectionist, do your blocking methodically; each stroke calculated, sand in one direction only, vary the direction (north, south, east, west, 45 degs, etc), and COUNT the strokes. Use a hard rubber block or short board, and finish with about 240 grit sandpaper(dry).Comment
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Re: C3 Body work
If you strip the car to bare fiberglass for painting, use premium fiberglass-safe stripper (3-4 gallons) to take off the color and sealer coats, then wet sand off the red oxide primer using 240 grit sandpaper. Work a small area (2-3 sq ft) all the way through from stripper to sanding off the primer, and repeat until done. If the car has already been stripped once, then the bottom primer coat will not necessarily be red oxide like the factory.
Soft rubber sanding pads will perserve more of your fiberglass character (if it hasn't already been blocked), but use a hard rubber sanding block on the rear deck (wherever you have dings)...you will see every ding clearly because it will be hard to get the red primer out of the low spots. To clean out the dips, you will probably have to sand them with your finger. Mark them or record the dings some way for future reference.
Roughen the area to be filled with 80 grit sandpaper(dry), then apply a skim coat of quality filler directly over the low spot. Don't let your 80 grit sandscratches go beyond where you are filling, or they can cause you trouble later. Try to build your filler just slightly above the deck contour, and then block it flat.
If you're a perfectionist, do your blocking methodically; each stroke calculated, sand in one direction only, vary the direction (north, south, east, west, 45 degs, etc), and COUNT the strokes. Use a hard rubber block or short board, and finish with about 240 grit sandpaper(dry).Comment
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Re: C3 Body work
Thank you.Comment
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Re: C3 Body work
Thank you.Comment
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Very Important...
Brian, I forgot to mention...after you have stripped the paint from an area, wipe any stripper residue off the surface with lacquer thinner, and flush the area WELL with water to neutralize the stripper.Comment
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Very Important...
Brian, I forgot to mention...after you have stripped the paint from an area, wipe any stripper residue off the surface with lacquer thinner, and flush the area WELL with water to neutralize the stripper.Comment
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