Summary for anodized aluminum in deionized water Discussion
Anodized aluminum or stainless steel in deionized water is discussed in the context of whether a product will corrode. Ehsan Rezaei asked if there was any update on compatibility of DI water with anodized aluminum. Bo replied that Mark’s original 2004 post was unlikely to be answered directly, but noted that a linked discussion suggests sealed anodizing is generally compatible. He added that hard anodizing should be more resistant because it is thicker, though hard anodizing is usually not sealed. Mark K then said he had been told 3XX series stainless steel holds up well, but his bigger concern was hard coat anodized aluminum and whether the product itself would corrode, not whether ions would enter the water. An editor’s note pointed to additional aluminum-in-D.I. water information in thread 10156.
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Q. Hi Mark,
Have you found your answer regarding compatibility of DI water and anodized Al?
Ehsan Rezaei
– Vaud [Switzerland]
August 9, 2022
A. Hi Ehsan. Mark’s posting is from 2004 so he’s unlikely to be monitoring this page and we’re unlikely to be able to reach him. The thread linked by the “Ed. note” implies that anodizing, if sealed, is generally compatible. Mark’s hard anodizing should be more resistant because it’s thicker, but hard anodizing usually isn’t sealed. Please tell us about your situation. We can’t fully resolve Mark’s situation because we’re missing some data, but we can hopefully resolve yours if you provide it.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
A. The pH value of the water and the conditions, such as temperature, are important. Colorless oxide layers are generally stable but may become blotchy. Hard oxide coatings are more durable, especially when sealed in hot water. In Switzerland there are various finishers of such layers.
Joerg Beerli
– Hallau, Switzerland
September 15, 2022
⇩ Similar, related, Q&As — oldest first ⇩
Q. How well does anodized aluminum hold up to deionized water? How does stainless hold up to deionized water? We have a customer that wants to use one of our grippers in a deionized water washdown and is concerned with corrosion or deterioration.
Mark K [surname deleted for privacy by Editor]
Pneumatic Gripper Manufacturer – Monroe, Connecticut, USA
2004
A. Dear Mark,
It depends on your customers’ needs; are you concerned about metal ions in the water or corrosion on your item? I have used a SS316 heat exchanger for DI water, and it’s not corroded yet..
Best regards,
Bo König
Food industry – Odense, Denmark
Bo,
Thank you. I have been told that 3XX series stainless holds up well. My bigger concern is the hard coat anodized aluminum. I am not concerned with getting ions in the water, I am worried about our product corroding.
Regards,
Mark K [surname deleted for privacy by Editor]
Pneumatic Gripper Manufacturer – Monroe, Connecticut, USA
Ed. note — Mark: Some additional info on aluminum usage for D.I. water is on thread 10156.