plating, anodizing, & finishing Q&As since 1989
Suitable anodizing power supply question
Q. I have been looking for a power supply for a while and just came across a Watson 24 Amp power supply with variable voltage, it is in the "CB and Amateur radio" section of the paper. Will this be sufficient, is there anything I should look for on the power supply to be sure that this will do the job? Any swift response would be much appreciated.
Thank you,Robert Harrison
- Stepaside, Dublin, Ireland
A. The voltage needs to be controllable from near zero to 15 volts minimum. 18 or 24 V would be quite useable without modification. 24 amps will anodize about 1.5 sq ft of total area. You might be able to nurse it to 2 sq ft of area, but don't bet on it.James Watts
- Navarre, Florida
Q. What type of supply would you recommend for various plating and anodizing processes?
I am looking for a supply that I can run in my aluminum anodizing tank, Nickel, Copper and Chrome plating tanks too.
I am new to this and would love to cap off all my issues in one go with 1 power supply
I have a 0-24 V / 50 amp Constant DC power supply in mind.
Would it be wise to find one that has both variable current and variable voltage?
- Canada BC
A. Hi Chris. Before trying to answer this specific question for you, I think we need to bring the readers up to speed in order to not mislead them. Just as it's not ideal to try to use a welding machine as a battery charger, or a battery charger to power your audiophile component system, people need to realize that the right power supply for plating or anodizing is a plating or anodizing power supply (rectifier) designed for the particular situation.
Often, anodizing rectifiers will have "ramp control" to slowly raise the voltage during the anodizing cycle (when you start anodizing, the parts are highly conductive and you must use very low voltage or the parts will "burn" and be ruined; but as the anodized coating builds, it is highly insulating and the voltage must be continually increased or the process stops). Chrome plating rectifiers may have external "chokes" (large inductor/capacitor networks to filter out any "ripple"); but at the least they are 3-phase devices with much less ripple than a single-phase power supply. Plating rectifiers may have automatic current density control, so larger and smaller loads plate at the correct current; etc.
Chrome plating requires perhaps about 4X the current density of copper or nickel plating, and if the current is too low, no chrome plating will occur at all.
So your question is not really what should you use for a power supply, because the answer would be "4 different power supplies, each designed for the specific process"; your question is more like "what do you think I can get away with if I'm lucky"? A patient hobbyist can surely get away with much less than a production shop would require.
Unfortunately, a "constant current" power supply has no chance of working. With a 50 Amp variable power supply you would be able to plate parts of maximum surface area not much more than 36 square inches, like a plate about 4 to 4-1/2 inches square ... is that big enough to meet your needs? Best of luck.
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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