Where the
world gathers for metal finishing
Q&As since 1989


-----

Anodizing current per square meter?

What is the time and Current drawing per square meter at 25 micron with 20 volts applied (dc) at temperature 70 deg c.

Ravi Ravi
Electrical maintenance - Bangalore
October 23, 2010

---

If you wish to get 25 microns, which is 1 mil in English^^American units, you can apply the "720 rule" to learn that 720 amp-minutes will produce the 1 mil. For example, you could anodize for 36 minutes at 20 ASF. But we can't determine the current from the voltage because many other things affect the resistance.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 25, 2010

---

Have to correct you there Ted, mils are American units, not English. If you come over to this side of the pond 1 mil is 1 millimeter, this has caused confusion over here where 0.001" is 1 thou (1 thousandth of an inch), not a mil.

By the way, do you know how you get from 0.001" being called 1 mil? I've never worked that one out :)

Brian Terry
Aerospace - Yeovil, Somerset, UK
October 28, 2010

---

Correction made, thanks. "Mil" is latin for a thousand, but beyond that I don't know the derivation of a mil as a thousandth of an inch -- it's probably slang rather than an official unit or official word in the language anyway.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 28, 2010