Painting aluminum

[CarlyBoy]

With a little research, looks like I can confidently paint aluminum sheet if it's properly prepared. Just one concern: the parts that are attached to the chassis. Specifically, when jacks, switches, and the like are tightened down, isn't there a chance the paint will chip under the pressure? Thanks for any help...

[EdT]

It depends on what kind of paint you are going to use, but most aerosol laquers and enamels will chip once dried or crinkle if turned with pressure against a lock washer, anyways you do need to have the jacks grounded to the enclosure anyways. I am thinking of using a lapping stick which consists of a wooden stick tipped with lapping compound on a drill press to clean up the area for a clean and professional result. around where the jacks will be inserted, but just small enough that the washer will cover it up.

[Cal Weldon]

Are you planning to etch before painting?

[CarlyBoy]

Yes, Cal, I was planning on etching the surface prior to painting. I pretty much assumed this was mandatory for good paint adhesion.

[Cal Weldon]

I find etching the most effective. The "other" ways of painting aluminum I haven't had much success with.

[CarlyBoy]

What kind of paint have you had the most success with, Cal? In my case it has got to stand up to the heat of tubes.

[Cal Weldon]

Barbecue paint maybe?

I don't know. My job was to load the extrusion into the acid and zinc tanks. I wasn't allowed near the spray booths. I just remember how important proper etching was to a good job.

EDIT: Most of the painting I have tried with aftermarket stuff was for touch up. All I know is that they don't work as well regardless of how well sanded or clean it was.

EDIT2: Is enamel a good paint for heat?

[grimberg]

I have had success painting aluminum using two different approaches, both of them with Rust-oleum products. The first method is to use Aluminum Primer and then any other paint spray over it.

http://doitbest.com/DoItBest/Main.as...=64&SKU=782327

The second approach is to use Appliance Epoxy directly on the aluminum surface, with no primer. It is available at Home Depot.

http://www.rustoleum.com/product.asp...ct_id=33&SBL=1

It is more expensive and the color selection is limited, reason why I prefer using the Aluminum Primer.

[theAnonymous1]

I've used zinc phosphate based etch primer with good results. It was similar to this stuff.......

http://www.prestomart.com/cgi-bin/st...rods&pd=400135

I also suggest bead blasting the surface instead of sanding if possible.

[XEAGLEKEEPER]

When purchasing your primer get self-etching primer. I've had real good luck painting aluminum intake manifolds with this type of primer. Of course I had beadblasted the surface first.