Aloha, fun & authoritative answers -- no cost, no passwords, no popups
(as an eBay Partner & Amazon Affiliate we earn from qualifying purchases)

Metal finishing Q&As since 1989

-----

Pit left on the electropolished surface

Houston, we have a problem. We did electropolishing on 316L Vim/var material (after hand-polish). We even used diamond paste to do manual pre-polishing. After EP, we found pits on the surface. We get darker finish some time. We can change the duration of EP (20 seconds only). Could you give us some clues? The polished surface gets even worse after "diamond" paste - polishing.

Liu Song Yun
Compart manufacturing company - GuangDong, China
2006

It is very common in electropolishing that the parts will pit or etch if it is not done quite correctly. The parts must be properly clean, there must not be excess water in the solution, and the current density must be high enough to get out of the "etching range" and into the "polishing range", as three quick examples of things that cause problems.

The best readily available book on electropolishing is the Electroplating Engineering Handbook [on AbeBooks or eBay or Amazon] , but you could try to contact AESF (www.nasf.org) about whether they have any copies left of their "Illustrated Lecture on Electropolishing".

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: