Painting Aluminum

I've searched the 'net and found very few references talking about the "best" or "correct" way to paint aluminum.

On one hand, Aluminum is nice because it doesn't rust (well, it oxidizes, but it doesn't burn away), but I've never had much success getting paint to stick to it, prolly because of that oxide layer?

Some sites say to use a sand wheel and mark up the AL first, others say self-etching primer will work fine on its own.

Any recommendations/experiences?

Also, I haven't found self-etching primer in any normal department store such as Farm & Fleet, or Wal-Mart - do I have to get it from a body shop supply store or automotive parts store?

-Brad B.

[snotzalot]

U-Pol is a very good self etch primer and is available at many auto paint suppliers in rattle cans. It's also available online at: http://www.autobodystore.com/

Originally Posted by Bradley Berthold

I've searched the 'net and found very few references talking about the "best" or "correct" way to paint aluminum.



-Brad B.

Hi Brad - I think the answer might lay in what kind (size) of part you are wanting to paint. Not to mention the final application.

In the medical equipment manufacturing industry there was a time when the ONLY acceptable method was to first have the part plated with a Chromate Conversion prior to paint. Old School!

However in the last few years we have had it painted with a oven baked Polane - nasty stuff, but man is it durable and did it ever stick!!!
With all the advancement sin paint I doubt it is still THE STUFF to use but it sure was once!!

I will look forward to see what the experts reccomend for a home user - In therory I might get my dragster panels straight enough for paint!!!!

Jacin in Ohio

Student of the ancient art of bashing the crap out of metal until it looks like soemthing useful.

Your mileage may vary.

[Randy Ferguson]

Hi Brad,
I have the info at work. I'll try to get it posted tomorrow. You may have a look at http://www.ppg.com and maybe you'll find the answer there. You should use a cleaner and a conditioner, followed by 2-3 coats of epoxy primer as soon as possible. I prefer House of Kolor KP2-CF epoxy primer to that of other brands, since it is sandable, and many of the others are not. There is no need for a primer/surfacer if you use House of Kolor, whereas the other companies recommend it over the epoxy. Many have the false assumption that House of Kolor is way higher priced than other leading brands, but that is totally a myth. Run the numbers, you'll find out!

Brad, have you ever tried dupont vari-prime? Its pretty good stuff. It's 2 part self etching primer. I used it when I worked in the body shop on aluminum truck hoods. 2 coats followed by 2-3 coats of primer-surfacer, then block sand.I used it on my camaro and every place that got chipped or scratched you could see the vari-prime was still there, pretty tough stuff!

hey guys...Harold gets the prize! NOTHING bites like Dupont Vari-Prime! Jacin mentioned "old school".....but this is the oldest of schools. it was introduced in the 40's for painting truck bodies and bus bodies that were made out of aluminum and also galvanized steel(then someone figured out it worked excellent on planes). it also is one the most rust prohibiting paints you will find. this stuff wrote the book on "self-etching". it sticks without fail to whatever you aim it at.....even stainless and glass. around '81 or '82....i painted two delorians starting with Vari-Prime to make it all stick(i've got pics plus witnesses and one of the cars is still around!) after using it for many years...i have NEVER seen it fisheye....it works great for door jambs or under hoods or anywhere you might worry of fisheyes or if you have stripped one and you worry of surface rust under the paint. you don't have to use metal-prep or any other surface preparation. the best prep is to wash whatever with a scrubby pad(scotchbrite) and half-strength joy making sure you have a good clean surface. one negative is that it is not very sandable. you can scuff it with scotchbrite and cover it with DP-90 or the HOK primer Randy mentioned......the Vari-Prime bites to the surface and the primer bites to the Vari-Prime and is workable. this sounds like a lot of work but if you are painting something that is troublesome like aluminum or galvanized or stainless(?) or glass or anything!.......Vari-Prime is no gamble....it sticks!!!! you can use it instead of adhesion-promoter on plastic or urethane bumpers or trim too. if you are painting a car....make sure you cover the glass...both sides(clear contact paper..like for shelves..works great).... or you will be replacing it......not razor-blading it off. you have to get it at the auto-body supply......and when you ask for(or price) a gallon it might seem expensive....but you effectively end up with two gallons...you get one gallon of paint and one gallon of special acid(!) and you mix it 50/50. you can get it in quarts but it is expensive that way. and don't put it in your good paint gun...it will never be the same...buy a binks copy at the flea-market...and clean up imediately after because it will start to eat in to whatever it is on. i didn't mean to write a short-story...but i've been using this stuff over 25 years and it's never let me down. try it . .........later