NMFRC
 

NCMSCompliance Assistance Centers

Funded by EPA
through a Cooperative Agreement

EPA

Disclaimer
The information contained in this site is provided for your review and convenience. It is not intended to provide legal advice with respect to any federal, state, or local regulation. You should consult with legal counsel and appropriate authorities before interpreting any regulations or undertaking any specific course of action.

Ask the Expert Question-and-Answer Archive
(Hard Chrome Plating)

by Randy Taylor, Advanced Tooling Corporation.
July, 2010

Chrome Stripping

Q. I need to determine if all the chrome has been stripped from a large part that we are going to salt bath nitrate, I remember a chemical we used to instantly detect if spots were missed. I think it was copper sulfate liquid. Is that correct? If so where do I find it? If not what can I use.

A. Purchase dry crushed copper sulfate crystal from a chemical supplier, mix about 1/4 oz. by wt. crystal (large tablespoon size) in a beaker of 200 ml of water. Mixes best on a warming plate with a stir bar. Slowly add 5-10 drops (10 mils) of sulfuric acid until the crystal is totally dissolved and the solution is a pale blue. Keep it in a sealed bottle out of direct sunlight. Label according to regulations.

Swab it on with a q-tip in the area you want to verify chrome removal. Bare metal will turn copper color, chrome or other coatings will not. Wipe off any access with a tissue. This technique works on most ferrous alloys. It won't work on CRES..

Good Luck,

Randy Taylor

 



| Compliance Assistance | Regulations | Directories | Resources | Hot Topics | News | Ask the Experts | Library | Online Training | About NMFRC | Search | Home |

NMFRC