[sage]

720 rule
Anodic coating will grow to a 1 mil thickness in 720 amp minutes at a current density of 1 amp per square foot

Anodize time
720 / CD * desired coating thickness from .1 to 1 mil
Ex. 720 / 4.5A CD = 160 minutes 160 * .7 = 112 minutes of anodize time

CD to amp setting on PS
4.5 CD is 4.5 amps per square foot
4.5 / 144" (inches in a square foot) = .03125A per square inch
.03125 * SA of the part in square inches = amp setting on the PS for the run.
Ex. Widget part with 30" of SA
4.5 \ 144 = .03125 .03125A * 30" = .94 amp (rounded off) setting on the PS to anodize a widget. If you have 3 widgets, multiply .94 by 3 to get the amp setting.

Ok, there we have it all in one place.
Thanks for that.
Hopefully that will clarify it for Newbees.

Now, if you stick with me for a minute, let me ask a few questions - not for our benefit - because you and I fully understand what's going on, But, like a FAQ, things can be clarified a bit more.

Q: Using the example above - What happens if I don't want to wait around for almost two hours (112 minutes) to get the job done? If I believe the "720 rule" and the "anodizing time" as stated above then I can half the time required by doubling the current because the rule is based on amp-minutes i.e. instead of 4.5 amps per sqare foot we use 9 and get the same number of electrons over there in half the time. eg.

720 / 9 CD = 80 minutes * .7 = 56 minutes instead of 112 minutes

All things being equal (and please don't confuse the issue with any other factors (temp, bla, bla)

This will produce exactly the same results True? of False?


Sage