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  for Metal Finishing since 1989
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Home painting of aluminum sheet

I need to paint approximately 5 square meters of aluminum sheet that makes up the body of a kit car. The application of the sheet metal prevents it from being treated in baths of any kind and therefore professional pretreatment. I need to find out how to pretreat the aluminum sheet in terms of which chemicals to use, the toxicity/pollution danger associated with these chemicals so I can work in relative safety (both myself and the environment) at home. The next issue is then what would you advise as the most suitable type of paint that can then be sprayed on the aluminum both as primer and the top coat.

Lourens Botha
Hobbyist - Pretoria, Gauteng, South Africa
2006

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First of two simultaneous responses -- 2006

Phosphate finish for aluminum(old US Army process):
1,8 lit butyl alcohol
1,4 lit isopropyl alcohol
0,45 lit phosphoric acid
0,9 lit water
Leave it on grease & oxide-free object 1-2 minutes,then rinse well,use rubber rubber gloves ⇦this on eBay or Amazon [affil links] and googles!Good luck!

Goran Budija
- Cerovski vrh Croatia

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Second of two simultaneous responses --

Go to any auto parts store and check out their paint section - they'll have primers and directions that are probably sufficient for you.

Also, use the search engine on this sight - you'll find quite a few letters describing how to go about the process.

Good luck!

Jim Gorsich
Compton, California, USA
2006

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Thanks for the response. I will investigate the direct paint options.

What kind of finish does the old army process give or is it only a cleaning process?

Lourens Botha
- Pretoria, Gauteng, South Africa
2006

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Dear Lourens!
That is standard pretreatment for paint or lacquer(like chromate or oxalate processes).Good luck!

Goran Budija
- Cerovski vrh Croatia
2006

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Painting aluminum sheet is something that aircraft builders have been doing for years with ease and great success. I find that washing with mild soap and rinsing is the start. The metal is clean when the water sheets off with no beads. Then a spray of any decent Self-etching primer ⇦this on eBay or Amazon [affil links] followed by the paint of your choice.

Bob Fritz
- Placerville, California, USA
2006