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Q&As since 1989


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Long-life paint finish on alumuinum casting

 

The paint finish on some die cast aluminum/ aluminum alloy architectural lamp housings is flaking off. The surface underneath is corroding. Can anyone suggest a suitable re-finishing process in black or white, which will stand up to prolonged exposure outdoors.

John Kirkwood
- Horsham, UK

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What pre-treatment do the lamps get?

A chem film under the paint would help it last longer.

Better still unsealed anodise and paint within a few hours.

This is more an answer to stop the problem rather than put right ones that have gone wrong.

Martin Trigg-Hogarth
surface treatment shop - Stroud, Glos, England
 

I get good results on this application by a chemical pre treatment on castings aluminum alloys with chromating the parts. A process like Alodine with powder coating black and wihte. Good luck.

Flavio Stramare Ribeiro
- Curitiba, Brazil
 

I want to restore a Singer 221 sewing machine for my wife. The body of the sewing machine is made of aluminum. What is the best way to strip the old finish off and prepare the surface for painting? Also, what would be the best primer and paint to use? The aluminum has some corrosion in a few spots. Thanks!

Kim Glory
hobbyist - McKinleyville, California, USA