You find that its not hard to set the angle of the holes so that the jets of electrolyte don't break the surface. I'm recirculating 5 gallons at 420 GPH that's 7 GPM, it takes 43 seconds to cycle all of my electrolyte. The surface looks dead calm, but 1 inch below and to the bottom its really moving. I have no bubbles sticking to the work or the cathode ever.
I have many anodization curves for 1100, 2024, 6061, and 7075, at ASFs from LCD through 21 ASF. I'm not at liberty to share them until early July.
I'll cheat a little and just verbally describe a few.
These were 90 minute anodizations to grow "Type II 1/2" coatings up to 3 mils. thick, not what you would want.
18 ASF, 70.4 deg. F. 1:1 electrolyte, very accurately instrumented.
2024 started (+3 minutes) at 1.22 Ohms/sq,ft., and gently sloped downward to 1.05 Ohms/ sq.ft. at +90 minutes. The final coating thickness was 17um (0.7 mils) there were signs of dissolution (chalky residue) but dyeing was fine.
Contrast this to 6061; same ASF, temp., time, and electrolyte:
This rose rapidly to 1.10 Ohms/sq.ft. at +5 min. they continued to rise at a slower rate to 1.62 Ohms/sq.ft at +90 min. The thickness was 70um (2.75 mils.) no dissolution signs, dyeing also excellent.
I didn't provide voltages as these would be meaningless since the size of your work is so different than mine. You can calculate what the voltages would be for a given surface area.
PAR was not evident, I have found out with a lot of testing that it only works with weak electrolyte, and is most visible at LCD ASF ranges, it will not be visible at all with racking.
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