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Finishing Welded Aluminum

I will need to have some aluminum assemblies anodized. What special precautions will the welder need to make and what materials should he use so that the colors turn out uniform?

Richard Bendt
Naval Surface Warfare Center - Indian Head MD
2000

It really depends on the alloy of the aluminum used. There are specific types of filler rods used on certain types of aluminum alloys to give the best look and color. Although you can never get an exact match and you will always see the weld there are advantages to using the proper filler rod for the aluminum alloy used.

Jack McGuire
- Indianapolis, Indiana
2000

Another problem, in some aluminum applications, if there are areas where chemicals can become trapped and then leak out, some staining or white color will be noticeable. This is mostly true when anodizing color. To avoid, either mechanically assemble after anodizing or seam weld all trappable areas.

Kurt L [last name deleted for privacy by Editor]
- Brooklyn NY
2000

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I have a chart here that a few of my customers use, it works like a charm for them. They have also found that polishing the welds down after welding them tends to help the color also, its never perfect, but its about as good as you can get kind of thing. And these guys are right, trapping of solution can occur and you should be aware of that beforehand, because if it does, you're gonna be told it was because of the weld by your anodizer and you might as well hear it from another one for verification :-).

Seriously if you take your time, ensure the welds have no leaks, and use the right filler, you should be fine. Again, if you need the recommended filler when anodizing is your prime concern (it is, in this case and always should be when you're welding aluminum IMO, it's good design technique honestly).

Matthew Stiltner
- Toledo, Ohio
2000