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Do I need anything more than self etching primer to paint over powder coating?

22K views 11 replies 8 participants last post by  mikey 
#1 ·
Hi,

I purchased some skid plates that have black powder coating. I'd like to paint them a different color.

I was going to spray self etching primer directly onto the powder coated surface and then paint with rust-oleum spray paint. Would that work? Or, do I need to sand with 180 grit sandpaper?

I hate sanding so trying to avoid it.

Thanks
 
#10 · (Edited)
I've rattle canned over powercoating many times. You need to sand with like a 400 grit paper to give the paint something to grip to, I usually use a DA sander to make it easy. Then use a wax and grease remover to clean the surface well before painting. Primer isn't necessary, but I always do a clear coat so it lasts longer.
 
#3 ·
No, the self-etching primer ONLY works on bare metal. The chemical "etching" component will have absolutely zero effect on cured powdercoat paint, which is actually plastic powder that had been sprayed on the part, then heated to melt it and "cure" it.

You will not be successful is getting ANY paint to adhere well to a powdercoated surface; think about the level of success you'd have painting a teflon-coated frying pan.

A very thorough and uniform sanding will help a tiny bit, and a thorough overall sandblasting would be a tiny bit better, but you'll never get adhesion as good as stripping down to bare metal by sandblasting, priming, and then applying multiple coats of wet paint.
 
#6 ·
Even if you got plasti dip to stick, which “might” be possible, anthing on the trail like rocks and sticks will readily rip into dip. It’s nor very tough. Since the only part of most skid plates that shows is the front part of the engine plate you might consider power sanding just that portion and go to town with lots of paint. The rest being black won’t really show - or matter. Sandblasting off powdercoat is a huge mega pain in the a$$ - I sandblasted the powdercoat off my front bumper and it took me 2 days. Will never ever use powdercoat on anything that is subject to scratching. Ok rant over :angel
 
#7 ·
I sprayed over my powdercoated bumper. All I did was scrap/grind off some of the flaking powdercoating, and spray it with black spraypaint. I've had zero issues with it and touch it up every once in a while after I scrape it off on rocks etc...
 
#9 ·
Overall success in getting wet paint to adhere to powdercoat is dependent on cleanliness, surface "tooth", and the type of powdercoat paint: epoxy, polyester, or some hybrid powder system. Polyester is hard to bond to, epoxy is a little better, especially if you can give it a light sandblast to get a matte surface.
 
#12 ·
IF you are going to media blast - use something better than sand. Aluminum Oxide will strip quite nicely and leave a good profile for paint to adhere to.
 
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