I have a '69 camaro. I finished sand blasting the undercarriage and put a coat of Omni (PPG) MP Series Epoxy on it.
I was reading the product info sheet and it states, "MP Series Epoxy Primers must be scuffed and reapplied if allowed to sit more than 3 days".
Wouldn't you scuff it before you put another layer of paint or primer on it no matter how long of time between???
I was planning on doing some body work under there to hide welds (new floor pans). After bondo I was going to shot 2k primer over body work scuff and then shot the chassis with Eastbay Chassis Black.
If I apply 2k primer within 72hrs do I not need to scuff the epoxy?
Do I need to apply 2k primer on entire area or just to cover body work?
Thanks in advance.
(MartinSr is the man! and thanks to all the others that post and reply):hurray:
Brian

many epoxies have a large window for recoating,, if within their recommended times you shouldn't have to scuff it.. i'm not familiar with that epoxy though. and yes if within time frame you can just apply the 2k over the top of it without any issues. If left more than overnight I would scuff it just for piece of mind.. I mean it would only take you minutes to do a quick light scuff.

You can do just the body work areas or whole panel, but i would always do the whole thing on a resto type project. that way you'll have enough product to block out.

If you have missed your overcoat window you have to scuff it up. If I go passed 36 hours I always scuff it up. Most manufactures say that you can do a solvent wipe down if you're close to the overcoat window and be OK but if you going to wipe everything with a rag why not hit it with paper instead and then wipe to make sure. I was close on the overcoat window on my trailer and I didn't worry about it, now the top coat on the deck is peeling in sheets. Time to sand off and start over.

Ouch thats a costly mistake!!!
Yeah don't go past the recoat window..

I learned my lesson on that one. Never ever try to short cut.

Thanks for the replys. May the scuffing begin....

Good luck to ya!!