Where the
world gathers for metal finishing
Q&As since 1989


-----

Bronze Finishes

2001

Hello,

We are a small new company that casts bronze and aluminum grave markers. I am looking for a paint and clear finish to use on the bronze. We paint the whole marker, then when the paint is dry we sand the lettering, borders and artwork, after this we clearcoat the marker.

The problems we have encountered with the finishes we have tried are: some paints dry too slow(it is tough to sand gummy paint, but we have had to do this in order to get the clearcoat on fast so that it does not lift the paint). The sanded bronze turns green under the clearcoat the paint fades bad in a short time the paint is soft the finishes start to deteriorate fast.

We have tried spray cans of paint (fading problem), latex house paint(I haven't checked this one to see how it's holding up) an air dry alkyd paint (dries slow and the clear- coat for this is allowing the bronze to turn color underneath). One lacquer we tried turned yellow right away and is peeling off, very unsightly.

I have tried different metal preps too, Xylene, deglosser, alcohol, sandblasting, and using abrasive cleaners with a wire brush.

Can anyone offer any ideas? Would a two part paint or bake on coating be the key. I would like to stay away from anything too hazardous, but maybe this is not possible.

Thanks for your time and any help you can offer.

Scott J. Keidel
- Dickinson, ND, USA

Dear Scott,

A two part polyurethane or a baked coating will give you the best results. You also won't have as many problems with lifting when you topcoat. Ask your paint supplier to give you paints with compatible solvent systems. If that clear lacquer yellows, it's likely suited for interior use, check to see if it has a nitrocellulose base. Switch to an acrylic and you won't have any more problems there.

Good luck to you,

Jake Koch
G. J. Nikolas &Co.,Inc.

Bellwood, Illinois

2001