Ask the Expert Question-and-Answer Archive
(Hard Chrome Plating)by Randy Taylor, Advanced Tooling Corporation
July, 2007Chrome Stripping
Q. How does NaOH (10oz/gal) affect 15-5 PH Stainless after 10 minutes exposure in a reverse current strip?
A. As a rule, precipitation hardened stainless steels are safe in NaOH & water stripping chemistry, but there are many reasons why stripping chrome from any substrate requires careful monitoring.
Things to be concerned about:
- Ensure that all current connections are sized properly for strength and impedence.
- Maintain DC voltage as low as necessary to avoid contact burn or over current,
- Maintain a PH of between 12.5 - 13.5 and encourage good circulation.
- Check parts often during the chrome stripping cycle.
- Pre-cleaning chrome to remove oils, greases, stains, markings and adhesives will ensure that the stripping process begins and ends uniformly.
- Never walk away or leave any parts in a stripping solution for longer than absolutely necessary.
- Never allow stripping parts to touch the tank bottom, sides or other parts.
When there's any doubt, I recommend running test samples under like conditions to verify the a set up is safe.