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

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

-----

Tolerable conc. of copper for cyanide zinc baths

My cyanide zinc plating bath is contaminated with copper.I know how to remove this impurity but I don't know the tolerable concentration of copper for cyanide zinc baths? anybody know?

Ali Showkati
Faravaresh Felez - Tehran-Iran

Hanson-Van Winkle-Munning Myron B. Diggin, states that as little as 0.075 grams copper/liter has an effect on the deposit. 0.30 g/l will show darkness in the deposit after 1/2% nitric dip.

Copper is removed with low current cathode dummy, density (up to 2 amperes/square foot) until the copper concentration has been reduced to less than 0.04 oz./gal (0.3 g Cu/liter), then use zinc dust [on eBay or Amazon] , 1-5 lbs./ 100 gallons of solution volume, filter after 20 - 60 minutes.

Tom Pullizzi
Falls Township, Pennsylvania

(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: