I have been painting various black METAL trim parts on my 67 convertible. I sand and wipe with acetone. I prime with a high quality SEM or Rustolem product. When I apply the black top coat the paint get little pimples or tiny craters. I am using semi gloss trim paint from Eastwood. ( under hood ) that I shake with a can shaker. The temperature is about 70 degrees. Very frustrating.. Thanks,

 

Hard to say what is wrong but I do know I do not use acetone as a product to remove oil and grease. It dries way too fast. I use the approved wax and grease remover for paint. I use Transtar SCAT 6311.

Using a wax and grease remover CORRECTLY is just as important ( if not more important) and using a good brand. IF you do not use it correctly....the process is pointless. DO NOT use fabric shop towels. REGARDLESS if they have been laundered. Use specifically designed wipers for the paint industry or something like FRESH Bounty paper towels. Wet out a paper towel and apply to the area and get it wet. the with FRESH , DRY paper towels wipe it off until dry. DO NOT ALLOW the wax an d grease remover to still be wet on the area it was applied on and allowed to dry all on its own. IF YOU DO...you have accomplished nothing but other than lifting up the oil and grease and suspending it on the wet wax and grease remover and allowing it to lay right back down on the surface when the wax and grease removes flashes off again.

NOW...that wipe off paper towel is now contaminated with whatever you just removed off of that area you just cleaned....SO...do not use it again if it is wet with the wax and grease remover you just wiped off the are. paper towel or wipers are cheap. Now the towel that you saturated with wax and grease remove can still be used to apply more of it to the next area. BUT if you see that that application paper towel is getting dirty just by applying on the wax and grease remover....logic would tell you that all you are doing is spreading around grease and oil to areas you are trying to clean.. SO get another towel and get it wet and apply it on the next area.

It is hard to say if these dimples are in your primer and they show up when you apply the paint.

I would test your procedure on a piece of flat metal or soda pop can and see what happens and if you still are getting these dimples.

And I assume you are sanding the primer you have applied to the parts you primed??? And not just painting right on top of it after it has dried.

DUB

 

What useful advise! Thanks, I'm anxious to try it

 

do a test sample like dub said. rustoleum is reallyhit or miss sometimes. I prefer not to use it for multiple coats.
when i do use it, I try to let it dry for at least 2 days. scuff it and recoat it.
It takes forever to dry properly which might be causing the pops.

id find a differnt primer(sem black etch). or just use the trim paint direct, ive had decent results just direct to metal red scotch pad, let it dry and recoat.

 

Thanks will try it..
I don't like Rustoleum paints. Like you said, it takes forever to dry. Eastwood semi gloss under hood paint is really nice. Also Krylon is good but they don't seem to sell a semi gloss or low luster black any longer

 

As mentioned that the Rustoleum paint may take some time to dry and it is often times NOT the paint to use for someone who is in a hurry. AS for the paint itself...it is really good IF you can wait.

DUB