Disregard the calculations regarding the 720 Rule. They are incorrect. See bottom of thread
Justin;
The problem is, as far as Caswell is concerned, that they only support the LCD method. I've tried the battery charger and the high current methods and have had no success. The LCD method has worked repeatedly for me, but I understand your issue regarding time.
Since time is a factor, and you already have a batch of 2:1 electrolyte mixed, try it at an 18 amp current density.
Just so all the math matches:
For a piece 0.06 sq/ft, your setting on the power supply would be about 1.08 amps (a little variation isn't going to have much of an impact). Make sure it is in CC mode!!!
According to the 720 rule, you should anodize for 2.5 minutes.
(720 / 18 amps * 0.06 sq ft * 1 mil) I picked 1 mil as your desired coating thickness)
As you state, keep the tap water out of the mix. It may turn out to be a non-issue depending on the quality of your tap water, but at this point, lets eliminate as many variables and potential problems as possible.
Sorry about the repeated question about the alloy. I missed your statement about it being either 6xxx or 7xxx.
Is your electrolyte being agitated? If you don't have a pump set up for this, use a wooded spoon or plastic spatula to stir the electrolyte for the 2.5 minutes you are anodizing. The agitation does make a dramitic difference in the results.
Actually, the connections that are of major concern and the cause of most problems are:
1. The connection to the cathode plate. is the attachment point between the lead and the alum. air tight? It is possible that if electrolyte leaked into this area, it would ruin your connection. If possible, pull the top of the cathodes out of the electrolyte. This will eliminate the potential of electrolyte getting into the connection. If the connection point has already leaked, you'll have to clean it. Aluminum and Lead salts have a tendency to build up at this connection point and can ruin the connection.
2. The threaded connection to the anode. Are you tightening the connection, almost to the point of the aluminum breaking off? You have to tighten it so firmly that the metal from the alumimum wire 'cold forms' and flows into the threads of the anode. Otherwise, electrolyte will get into it and the connection point will anodize and not the part itself.
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