Has anyone tried painting over a powdercoated part? I have some freshly, professionally powdercoated inner fenders that are black. I'm thinking of scuffing them up, then spraying them with a few coats of light colored epoxy primer, then a top coat of urethane white paint. Any reason this wouldn't work?
When I have done some High End builds, I always powder coat the chassis and then scuff it and shoot the outside rails that show with single stage enamel and color sand and buff it. Works great and gives a better quality finish. You get the coverage and protection of powder and the finish or real paint.
No reason why it won't work. Powder coating is basically electrostatically applied, oven baked paint. It's a great, fully cured surface that can be used as a base for painting, just as Hotroddon points out. There really is no need to spray the sanded powdercoated areas with an epoxy primer unless there are flaws that you want/need to fix prior to painting. I'd sand it thoroughly and use a none sanding sealer then the top coat...
It adheres well. The only problem I see with that is EVERY rock chip that happens will chip paint and show up as a black spot from the powder. Past that, paint away.
OK thanks. My thought is to use the primer to help 'hide' the black so I don't need 300 coats of paint. Would the sealer do as well for that? These are inner fenders on my '58 Chrysler, and it's only the inside (engine side) that I want white so I don't expect a lot of chips
Sealer will help to hide sanding scratches and also help with adhesion. If you're using a single stage urethane or acrylic enamel for the top you should not need any more than three or four coats to cover the black. Check with your paint supplier about using a white or light gray sealer, which will serve the same purpose of making it easier to cover the black while providing the benefits I listed above. Posted from the TJJ App for iPhone & iPad
Before I painted my frame , I had it powdercoated with epoxy primer powder, After that it was sand w/320 , then basecoat and clear .
Anytime I can't make paint stick well to a metallic surface and my customer approves I send that part out for Powder Coating. I get it back and paint right over the Powder Coat. It is the best primer I have seen. Normbc9
Anytime you can't get paint to the metals commonly used on automobiles it's because the surface is not prepared properly and/or contaminated with something. Powder coating has the ability to bridge over contamination and bad prep, but when that's done it still isn't adhered as it should be.
Not trying to be a smartass here. Why wouldn't you have the frame powdercoated the finish color you wanted, instead of painting over a powdercoat primer?
Good question . The reason that I chose to do this was because that was the product recomended by the owner of the powdercoat company. He said that the paint would adhere better than over regular powder, since it was an epoxy designed to work with painted topcoats . It's been done for 4 years now and the car has over 17K miles with no problems of chips anywhere. On my previous roadster I painted over reg. powder and did'nt have any problems either and the one thing that I did notice was that the epoxy was a little harder to sand than the reg. powder. Hope this answers your inquiry.
Great little tech item guys. Thanks for all the posts. I would have guessed that powdercoat would have been too hard to scuff up properly, but I was worng. Cheers.
What I learned from a dude who has powder coated for a living since the late 70's.... he explained to me that you can use an adhesion promoter to paint over powder coated surfaces (he recommended BullDog) and said that you don't need to scuff the powder coat. The promoter will make paint stick like powder if sprayed correctly, it will last decades & add extreme protection from corrosion with all the extra layers. He stressed always use a UV clear coat to keep the color from fading in certain areas exposed more to sunlight.
Paint it the same color as the powder coat problem solved. Its like using dark primer under dark paint and light primer under light paint.
I tend to get any rim powdercoated before painting. There's a place near me that will blast and powdercoat rims for £25. Drop off an old crusty rim and get it back looking like new. I've normally got the powdercoat guy to coat the rims in the nearest colour to what i'm using, hit with 320 wet and dry, paint then clear. Never had a problem holding up to our shitty roads and climate.
We had a tube frame powder coated a couple of years ago. Talking to the shop guy, he told us that he bakes the frame while bare to cook off any oils or impurities, Lets it cool, powders it, bakes again. His thoughs are that powder coating is just paint without the reducer/thinner.
I haven't heard "XIM" in years.... Are you referring to the old time sealer? It was clear...more like yellow-ish... Can't recall who manufactured it. It was a general, all purpose sealer if I remember right.
You got it right with the epoxy primer, It sticks real good, personally i would use epoxy primer tinted to the same colour as my topcoat.
better make sure the powder was done right .i had a panel were the primer started to crack .and was not bitting to the powder .i was told it was because the powder was not baked long enough .they claim if its bakeded long enough you should not be able to phase it with paint thinner .
The standard polyester powder coat is not impervious to enamel reducer or lacquer thinner. It softens/dulls them fairly quickly. One of the tests for powder coat is how quickly solvent attacks it. This is one of the advantages that catalyzed paint has over powder coating.
Just my opinion but I wouldn't have a frame powdercoated myself, too many possible problems, if it chips the rust will creep underneath the coating. . . Posted from the TJJ App for iPhone & iPad
thats called prebake and it lets the pores of the metal out gas. I prebake each and every item, porus metals benefit more from prebake but I still do it to everything just to make sure no oils of any type seep out of nooks and crannys of whatever it may be.