plating, anodizing, & finishing Q&As since 1989
Sizing A Hard Coat Rectifier
September 23, 2010
I am attempting to size a new rectifier for hard coat and although I can calculate load size by amps/ft2 I cannot calculate the volts required to push to 3000 amps dc. Therefore my question is, when hard coat anodizing at 24 asf, what is the max amount of dc volts a 3000 amp dc rectifier will need?Jeff Nathan
Job Shop - Bristol, Rhode Island, USA
First of two simultaneous responses -- September 23, 2010
The voltage required will depend primarily on the desired thickness of the anodize. Other contributing factors will be your operating temperature, acid concentration, and use of additives, and to some degree, the alloy you are processing. Increasing the contributing factors will reduce the require voltage for a given thickness. I would expect a 75 volt rectifier to be common for hard anodize operations.
Remember to size your chiller accordingly.
- Colorado Springs, Colorado
Second of two simultaneous responses -- September 23, 2010
75 Volts is a fairly common selection for a hard anodize rectifier. If you do very thick coatings or if you your bussing system isn't appropriately sized/connected, you may find that you need even more than that approaching 100 volts.
Jon Barrows, MSF, EHSSC