The authoritative public forum
  for Metal Finishing since 1989
-----

Rinsing Copper and Aluminum With DI Water

I am conducting leak testing of some sections of tubing that are half aluminum and half copper. In the past we have had problems with deposits from tap water being left on the surface of the tubing which is a cosmetic problem. If we use DI water, can we reduce the occurance of deposits on the surface of the tube and will DI water that is used for a short 10 second test but not wiped off afterwards cause any corrosion problems?

Thanks,

David Wayne Smithey
manufacturing - Nashville, TN
2005

---

2005

Even electronic grade DI water will not cause any problem.
You certainly do not need that quality of water. Lower levels of DI are available from many vendors and will work well.
If you only need a small amount of water each day, you might consider a RO unit from sears or lowes or home depot or similar store. The water is of a lower quality than most DI, but it should be adequate and will cost less.

James Watts
- Navarre, Florida

---

As long as the immersion time is relatively short, there should be no problems. However, any time that two metals that are so far apart on the Electromotive Series are connected and immersed in a conductive medium, corrosion is a potential problem. Since DI water has very low conductivity, there will be very little corrosion at first. However if you left the tubing in the water for hours or days, the corrosion would add conductivity to the water and accelerate.

Lyle Kirman
consultant - Cleveland Heights, Ohio
2005