Are you supposed to reach PAR using the 720 rule? I’m going back to some notes of some anos I have done (just using the 4.5/144 rule on the Caswell manual) and keying info into the 720 Rule Anodizing Calculator and I wouldn’t be able to leave a part that long with out going past PAR! For example:

I did a batch with a surface area of 118.17 Sq Inches.

Using the Caswell’s manual —–4.5/ 144 = Amps / 118.17 so Amps = 3.69
Using the 3.69 amps this batch reached PAR in 90 Minutes with a voltage of 10.2 volts!
Successful ano ! Nice color etc.

I keyed in the same surface area of 118.17 Sq Inches into the 720 Rule Anodizing Calculator (just for comparison purposes)!

I imputed
Surface Area = 118.17 in2
Thickness = 1 mils
Current Density = 4.5 Amp/Ft2

It calculates
Set Current = 3.69 Amps (same as my calculated amps with the 45/144)
Time = 160 Minutes (70 minutes past PAR???)
Peak Voltage = 11.25 Vdc (peaked at 10.3 volts)

I’ve keyed in a couple of successful ano notes and all are similar in comparison to 720 Rule Anodizing Calculator. So what do you do once you reach PAR and you still have and other 70 minutes to go according to the 720 Rule Anodizing Calculator. I’ve never used the 720 Rule Anodizing Calculator to ano anything but I’m trying to get familiar with it!

Thanks!