My '72 El Camino is ready for paint. I have primered the entire car with a primer that my paint supplier said was compatiable with a bc/cc. I was told that after final sanding to put a sealer on the car, because the bc/cc would cause the original paint under the primer to crack or bubble. I removed most the old paint but sure some is still there. Is this sealer actually needed.

Sealer has become a painters choice. Sealer can help lessen the amount of color coats but you must have a tinted sealer that matches the final color.

Sealer on the other hand can cause orange peel, and some like the Dupont's chromapremeir sealer can leave a Halo around the sealer edge.

If any type of paint reaction was going to happen then it would have happened. The only way the baseclear can lift the old paint underneath is if you sanded the primer surfacer to thin.

Is sealer needed in EVERY repair...NO. But if you are unsure then apply the sealer. Just follow the tech sheets on the flash time or inbetween coat times. If too soon then die back can occur

why does the sealer coat have to be tinted? I used PPG grey sealer under black and red paint jobs and they both came out great. Both were single stage enamel with hardener, does the BC/CC require the tint because coverage isnt as good?

It doesn't HAVE to be tinted but it makes it easier to cover if it is. There are some colors so transparent that is impossible to cover the wrong color sealer/primer with 3 coats.For example i had a repair on a tailgate of a new Blazer. It was dark blue metallic(i forget the name). I had used light gray primer and sanded it with 400 wet.It was about the size of a sofball. I wanted to keep the repair small so i didn't seal it and went right for basecoat.Now Dupont recommends Valueshade 7 primer or sealer for this color.Valueshade 7 is almost black. I took me fifteen,Yes FIFTEEN coats of color to cover that light gray primer! At almost $60 a pint for these colors you can see where using the right color sealer is a must.After that i have painted that color sealing it with the dark gray/black sealer and it is covered in 2-3 coats easily.

If he is a real friend then beverages should sufice!
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Guess I have too many friends. I'll try the next post!
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Originally posted by dsolomon:
Guess I have too many friends. I'll try the next post!
graemlins/beers.gif Or to many
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oops graemlins/clonk.gif