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


-----

White Stained Aluminum

We are running into a problem with aluminum from our supplier that we have not seen before. The aluminum stains when it is placed in regular drinking water (tap) or bottled water. We have seen this problem appear in the last 5 months and not before, we are still using the same supplier and supposedly the exact same product we have always purchased. The stain happens within hours of the aluminum being put in the water and looks like a white film on the metal and can not be removed by rubbing it off. Any help would be greatly appreciated!

Stephen Rooke
- Steinbach, MB Canada
2002

---

First of two simultaneous responses -- 2002

1. Look for galvanic potential

2. Look for calcium in the water

3. EDAX the white film and ascertain exactly what elements are there, then we can find the source.

4. See published paper above entitled "White Spots"

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

---

Second of two simultaneous responses --

I think you should mention the type of surface treatment in your inquiry before the contributors in this forum can better reply.

Dado Macapagal
- Toronto
2002