Hello there,
I'm in the process of trying to anodize 2 diffent sizes of 7075 aluminum. One piece is 19 sq. inches and the other is 35 sq. inches. I have 2 - 5 gallon anodizing tanks hooked up in parallel using a 20 amp/30 volt CC/CV power supply. I'm using a 1" square aluminum bar with tapped holes and drilled holes to tighten the titanium wire on that the parts are hanging from. One of the parts have threaded holes I'm able to bend the wire so the end is bent and pressing into the crest of the thread. The other part(19 sq. in.) only has drilled holes so it's a little trickier but I'm able to do the same thing. In each tank, I have 2 - 8" square lead plates for the cathodes so theoretically should be able to get a minumium of 128 sq. inches in each tank.
I tried wiring 2 parts in each tank of the same part(so either 70 sq. inches in one and 70 sq. inches in the other or 38 sq. inches in one and 38 sq. inches in the other) so the total square inches never exceeded 140. When I anodized the parts at 12ASF, some came out with black streaks through them, others looking like they only got anodized from one side and others that didn't even look like they got anodized.
I later tried 1 part in each tank to try and isolate the problem and still not getting consistant results(usually 1 anodizes and the other doesn't) I'm trying to attain Type 2-1/2 Hard Anodizing and am about ready to crack if I can't get this thing figured out.
If anyone has any ideas on how to solve this problem, please get back to me ASAP please - I have another 50 or so parts to do by Monday!!!
Thanks in advance,
Kevin
