Ted Mooney, P.E. RET
- Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Anodic Electrocleaning vs electrolysis of rust
Q. It was my understanding that in anodic electrocleaning, the workpiece was the anode. This facilitates oxygen formation on the workpiece to assist in cleaning. This seems to be recommended for ferrous metals. However, wouldn't this just cause rusting?
A lot of the common tutorials online I see for electrolysis of rust, such as those for cast iron, the workpiece is the cathode but it still uses an alkaline solution for anodic electrocleaning rather than an acidic one for cathodic electrocleaning.
What is the cause for the different configurations? Is it simply objective difference. With ferrous metals, wouldn't anodic electrocleaning just introduce rust to the workpiece?
- Chicago, Illinois
October 15, 2024
A. Hi Balor,
Every explanation of a physical phenomena is a simplification of course, and most of us pursue such explanations only to a deep enough level to be useful for our needs. So my explanation can be called over-simplified, or wrong, or whatever anyone wishes, but here's how I view electrocleaning:
Alkaline cleaning is useful for cleaning nearly all kinds of soils, and electrocleaning is merely an extension upon it which separates water into hydrogen and oxygen, forming scrubbing bubbles of hydrogen on the cathode and of oxygen on the anode to mechanically assist in the cleaning. Oxides can't/won't form in this highly alkaline (OH intensive) environment, and iron is not soluble in high pH solutions; so the oxygen just becomes scrubbing bubbles of O2.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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