Painting aluminum?

Considering buying an aluminum front bumper but have heard it can be hard to get paint to adhere to. Has anyone painted aluminum and if so what did you use and how does/did it hold up? Pics are always helpful. Thanks in advance!

 

Rattle can has served me very well on my Prinsu.
Rustoleum High Temp Paint

Get a nick, spray it.
Scratch it, spray it.

Nobody can tell its rattle can either.

Best photo I have at this time is of the cross bars.

 

do you have any issues with easy scratching or paint pealing off?

 

None what so ever.
I've driven through pine trees, scrub brush, thorns and hella tall grass.

Didn't use primer either.

 

I have an aluminum front bumper. No issues at all. Just primed it and the used the truck liner spray. I've had it for years...

 

Get it powder coated.

My first aluminum bumper, I used primer specifically for aluminum. Then Krylon flat black. It chipped and scratched.....

2nd bumper was powder coated by Pelfreybilt.....Tougher'n a $2 steak.

 

Did the same....i recommend a good self etching primer for aluminum for best results.

 

Thanks for the tip.

 

No problem I used UPOL brand and was very happy with it.

 

I sand, use self etching primer, then paint, then clear coat. Might be overkill but holds up great.

 

Honestly, I wouldn’t paint an aluminum bumper. Know this is an old thread, but I have a Relentless Fab aluminum bumper from about 2011/2012 that I obsessively prepped and painted correctly with a good acid etched primer and Rusto Hammered paint (multiple coats, cured correctly etc). It’s a good paint job in that 8ish years later there are zero adhesion problems EXCEPT Anywhere a small rock has hit it. It now looks like it has measles. Chipped from the very beginning.

Interestingly, you can’t easily flake or blast the paint off (pressure wand car wash) even trying to around the rock chips. Also, my rear steel bumper that’s been on for a couple years longer and painted the same way has no rock chips at all, and it’s gotten more than a few small hits to, though not like the front takes obviously.

Really wish I’d use bed liner or powder coated instead. Even with good adhesion, there’s something fragile about painted aluminum when it takes impacts. Maybe it’s the paint type, but the rear bumper says not. The only good thing for me is I think I can do a good touch up with the Hammered paint as it blends well. Just my 2 ¢.

 

Aluminum requires a light sanding and thorough solvent cleaning first, then self-etching primer. After that, regular sandable primer, sand and top coat as desired.Aluminum oxidizes, thinly, quickly and the etching primer will deal with that. That's why a TIG welder will brush the weld area with a stainless brush, clean with acetone and weld immediately after. The "cleaning" action of AC tig welding breaks up that thin oxidation.

Any finish is only as good as the surface preparation. Pay particular attention to edges and welded on brackets and seams when cleaning pre-paint. Trapped humidity and solvents are another cause of problems. Wait for a nice warm dry day,not in direct sun and wait for all materials to dry well before applying the next coat.

 

Yes, Agreed on all points. And that is exactly what I did. Not my first rodeo painting aluminum. I guarantee you no one could’ve done a more careful job. As I mentioned, where there are no rock chips after eight years the paint still adheres very tightly.

My real point, which probably got lost in too many words, is if the OP is going have an aluminum front bumper AND wheel it, no amount of good painting will protect it from a huge amount of rock chips over time. I believe that powder coat will do a much better job, and I also think that bedliner will do a better job, because the substance is tougher than paint. The impact of small rocks is enough to overcome the best paint adhesion. Or get ready to paint it every couple of years if you wheel it much as I do.

YMMV Depending on circumstances.

 

Yes, bed liner over proper prep is the best for a working type of bumper. It leaves a nice texture too that can conceal minor blemishes.

 

On an aluminum skid, I degreased, sanded with 60 grit, degreased again, then applied two coats of self etching primer and then two coats of enamel. The paint easily scratches and chips off. I would also recommend powder coat or bed liner, as they are more flexible and durable.

 

Any idea if I would have to take my bumper back to bare metal to do the bedliner? I wonder if I clean and prep the existing paint aggressively with denatured alcohol and sanding then shoot the bedliner over That? Or is that just going to be a disaster?

 

its raw metal, you should bite it and probably red brite or sand it with 500 lightly.

 

I think you will need to go down to bare metal and start over. Otherwise you may have a worse problem.

Automotive paint prep solvents are made specifically for removing wax, grease, silicone, and hand oils before priming and again before painting . In any case ,you have to turn and change rags frequently when cleaning with solvents to avoid spreading wax, grease ect. Denatured alcohol is a pretty mild solvent.

Dispose of any solvent soaked rags properly to avoid fires and wear protective equipment while using.

Rustoleum is easily lifted by paint products with "hot solvents" like acetone, lacquer thinner and similar thinners/ reducers so beware. Rustoleum is mineral spirits (paint thinner) based generally.


As always, follow the bed liner manufacturers recommendations for prep, priming and application. An email or phone call to them may yield good info. They know what works best with their products. An auto body supply place in your area that serves body shops can advise you on materials and products too.

 

Thanks for the detailed info!

 

Your welcome, good luck with it!!!