The authoritative public forum
  for Metal Finishing since 1989
-----

Spray painting Aluminum

Hello,

I am looking for some advice on painting some small aluminum plates. I am using a cnc machine to cut out some small pieces of aluminum (about 9" by 3"). They will be painted a variety of colours and need a flat finish. These are for some small signs to be placed indoors, so there is no need to worry about exposure to the elements.

I read in a very old post something about sanding first with 150 grit sandpaper and using epoxy primer. Can I follow this method and then finish them with flat spray paint?

This is a one time project for us, and since we normally are a woodshop it doesn't really make sense for us to invest in any expensive aluminum finishing techniques.

Any advice on this would be much appreciated. Thanks.

Robert Land
Full Circle - Indianapolis, IN, USA
2005

---

Yes, you could do that, Robert, but freedom from grease and oil is as important as a rough surface, so get them clean and keep them clean. The thing that many people don't recognize, so I'll say it for the general readership even if you already know it, is that metal finishing is a very highly jobshop oriented business, such that it should be easy to find a shop that can do a proper aluminum pretreatment and paint application for you that would include alkaline cleaning and phosphatizing or chromate conversion coating before painting.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005

I want to spray paint a batch of aluminium carry cases. Then maybe customize them with an airbrush. Can anynone give me some advice concerning this matter?

Andrew Feeney
consumer - Kuwait
2007