[drill_and_buck]

How long can you wait before applying a topcoat over zinc chromate?

Background info:
I took the afternoon off to paint some interior pieces. I etched them, then primed with zinc chromate and waited two hours before applying the special top coat I ordered (VHT black wrinkle plus).

I took the can of topcoat paint and shook it for at least two minutes then tested a spray pattern. Hmm, no color! Shook the can for another five minutes with the same result. It looks like the can was filled with clear coat! No problem I say, I ordered two cans. I grabbed the second can shook up it and got the same results!

Summit Racing is sending me out two more cans (great customer service) and they promised to test the cans before shipment.

My question is if I wait a week do I need to scuff the primer or add another coat of primer or can I just shoot the top coat?

Note: I have already painted and stripped the panel twice (don't ask), I have no desire to do it again.

Thanks in adavance for your help.

Mike Draper
RV-8 finish

 

[RV8N]

It was over 6.5 years from start to finish on my project. I zinc chromated all surfaces prior to riveting together. When I was ready to paint, I wet sanded with 600 wet/dry. I then sprayed an epoxy primer as a sealer (polyurethane cannot be put directly over zinc chromate), base coat, then clear coat.

Where the paint has chipped, it is between the base coat and epoxy primer, not zinc chromate. I think if you wait over 24 hours, you need to scuff with scotchbrite pad or lightweight sandpaper.

Kind of long winded. Hope it answers your question.

Karl

 

[drill_and_buck]

Thanks Karl:

To be safe I think I will scuff and then apply another light coat of primer before applying the wrinke paint.

-Mike Draper
RV-8 Finish