[FrankR]

I painted a bare metal trunk lid black for practice a few months ago. In about 1.5 months it was chalking. I'm new to these epoxy primers. When I get ready to apply my top coat color, do I need to do any prep work?

Should I use wax & grease remover or scuff it?

Am I worried over nothing?

[Bee4Me]

Am I worried over nothing?

Yup. It will chalk up but will not effect it's properties at all.
Wipe down with grease & wax remover or wash to remove any residue/dirt,180 sand and clean. Use cleanser like Ajax and wash or a good grease & wax remover.

[crashtech]

I think it's possible for UV to damage epoxy primer enough to affect future top coat adhesion. If it were mine, I would sand it pretty far down and reprime or at least seal before topcoating. Be sure to follow the paint mfrs recommendations for finish sanding grit. Usually 320 dry or 400 wet or finer is what you would want to use. Today I used 320 dry, then went back over it with 600 wet to sand some primer for paint. Fine grits are cheap insurance, especially with metallic paints.

[BarryK]

Epoxy caulking is only the top layer dieing. Does not effect the under layers
(exception to this is Por 15 -if chalk its shot)

So all you need to do is sand the top surface by hand or a DA with some 180
until you reach the good epoxy and apply one more coat of epoxy and go from there.

[Bee4Me]

Thanks Barry, I wasn't sure on if it needed a recoat especally if you laid 2 coats previous. Guess when in doubt,put on another coat.

[rrmccabe]

Frank always remember you have to scuff epoxy primer before topcoating once its outside its window. So it does not matter if it looks perfect and has no chaulk look at all. Check your tech sheet. I think you will find it says to sand it before topcoating after X amount of time. Probably around a week.

I am assuming all epoxies are thay way but not sure. Everything I have used is.

Alway refer to the tech sheet. They are usually downloadable online if you dont have one. Or post your product and someone can help you.

Rich

[BarryK]

Originally Posted by Bee4Me

Thanks Barry, I wasn't sure on if it needed a re-coat especially if you laid 2 coats previous. Guess when in doubt,put on another coat.

************************************************
When in doubt, its the best way.

If the epoxy has been outside it should always be re-coated.

I have taken a front end that was epoxied for 4 months but stored in basement while I did rest of car and sanded the epoxy and shot the 2k primer but it was not exposed to UV or any kind of industrial fallout.