Aluminum components are getting puncture holes during anodising

"The Surface
Treatment &
Finishing of
Aluminium and
Its Alloys"
by Wernick, Pinner
& Sheasby

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A. Hi, Nagendra. May we take it that your shop is experienced in electroplating but is new to anodizing? Anodizing is an electrically insulating coating. So when you begin the process you must start at very low voltage (or at a controlled current) or you will burn and puncture the aluminum. As the thickness builds and the electrical resistance rises, you must raise the voltage (or maintain the current) because it starts gradually becoming a better and better insulator.

So, in addition to obtaining some books about anodizing to get a deeper understanding, you will need to buy rectifiers that offer ramp control for anodizing. Good luck. And you need good contacts on your racks because if a contact is poor and broken when the voltage is low, and then conducts when the voltage goes high, you will burn the parts. Best of luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Ramp control is a lot more foolproof than an employee and will save a lot of problems in the long run. Some companies can retrofit some of the power supplies.

Pits can occur in the rinse tank and the dye tank in some cases. You need a book to cover the why's and the preventions as it is more than a 1 paragraph answer.
So, you need to know when the pit is occurring.