Primer over paint

[Apantaos]

I am rebuilding a 1996 Dodge Ram. There were some severe dents in the cornerpanels and some other minor body work that a have finished...using Lens videos of course. I am pretty happy with the way the panels came out even though I had to recreate the crease at the bottom of the panels with some wood, a hydralic jack and a shinking disk on the grinder. I used an aluminum loaded filler @ about a 16th of an inch thick and then used blue lightning for finish. However, when I started spraying the B/C (dupont paint) some spots started cracking on contact. I used a ful-fill primer then some dulplicoat primer sealer over the repaired areas, sanded down the entire vehicle with 220 and a DA sandeder, then wet sanded the entire vehicle. Something went wrong. I have re-sanded down the entire right side to OEM primer with some exposed metal spots. I was wondering if I could either sand down to the original primer and use an etch primer on the exposed metal...then re-prime the entire vehicle with fulfill or can I just scuff the OEM paint with a maroon 3m pad and try the B/C again? I am running out of time and need to have the truck done by this weekend.

Thanks in advance for any suggestions.

[Len]

This is why a novice should always use materials designed to be used together. There's a good chance that the variety of materials that you used were not compatible and are reacting with the new paint or with each other. If your new paint is cracking or wrinkling you may need to remove the Duplicolor or one of the other undercoats and apply an undercoat recommended by your new paint manufacturer.

If the original paint is in good shape you don't need to apply primer over it, just scuff and shoot. I would normally recommend that you use something like 400 grit sandpaper rather than a scuff pad on the exterior surfaces where you're apply a top coat. If you are applying primer over paint you should scuff the paint with 180 or 220 prior to the application of the primer.

[Apantaos]

Len - I suspected that it was the sealer as I had bought this at a different store. Real stores are closed @ 03:00. They assured me it would be compatible. However, I will never take another persons word for it. I will consult the manufactures technical data before applying. Everything else that I have used is recommended for the application and mixed to measure. The B/C over paint was a little fuzzy. Thanks for clearing that up. Thanks for your assistance.

Have a great one.