The authoritative public forum
  for Metal Finishing 1989-2025
  

  -----

Aluminium corrosion when used with copper in water

Does anodising aluminium protect it from the effects of corrosion caused by copper when both are immersed in water continually. and if it does what grade of anodising is required.

Jamie Mold

2006

---

Anodizing makes aluminum non-conductive and therefore removes galvanic corrosion as a factor. Also, the anodic coating is very resistant to corrosion and should cut down on all other forms as well.

So, in general, the answer to your question is "Yes"; and you could do a MIL-A-8625 / MIL-PRF-8625 [⇦ this spec on DLA] type II or III (preferably sealed) for the job. Type II would probably be more than sufficient and cheaper.

Now, in specific - what else is in the water? pH? salt water or fresh? how fast is the water moving (is abrasion going to be an issue)? Lots of factors can play a role in answering whether or not IN YOUR SPECIFIC CASE anodizing will do the job you need.

But in general - sure.

Jim Gorsich
Compton, California, USA
2006