As a member of the eBay Partner Network & Amazon Affiliate we receive compensation for qualifying purchases

Home /
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989


Blue Chrome defect in hard chrome plating

this text gets replaced with bannerText
spacer gets replaced with bannerImages

Q. I am a chemical engineer working in a plating shop where we Chrome plated parts, but in these last days during the application of the hard chrome we have many parts with blue Chrome. Any idea what is happening?

Your comments are welcome.


Michael Garcia
- Montreal Canada
April 27, 2022

"Hard Chromium plating"
by Robert K. Guffie

on AbeBooks

or Amazon

(affil links)

A. Hi Michael. We'll have to see what someone else says because I have never even heard of such an issue :-(
If you could send a photo to for posting here it might help. Thanks.

Luck & Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey
April 2022

April 28, 2022

A. Hello, Michael,

I've never worked with hard chrome, so I don't have practical experience, but I've read that blue chrome deposits means an iron contamination higher than 15 g/L and that this is more common in hard chrome than in decorative.
In this technical manual I'm reading, it is also written that there are no easy means to remove this contamination, just diluting the bath.

Also, is Hull Cell a common test for hard chrome? If so, it should give you some hints.

Some photos would also help finding the answer to your problem.

Hope this helps you.


Pedro Franco
Chemical Engineer - Nova Friburgo, Rio de Janeiro, Brazil

A. When you say "in these last days", I have to assume you are using the racks over/over without cleaning the contacts?

robert probert
Robert H Probert
Robert H Probert Technical Services
supporting advertiser
Garner, North Carolina
May 27, 2022

May 26, 2022

A. Hi Michael,

Having worked as a lab manger at a functional chrome shop before, I'm sure it isn't critical for functionality. But it is an interesting sort of defect. Are you plating over a different deposit (sulfamate, cad, zinc) or just over steel?

Q. We are running into a similar issue at my decorative chrome shop. The defect appears to be a rainbow iridescence that is VERY distinct only on certain parts (we see it on everything to varying degrees). We have isolated the issue to our Ni anodes but can turn the defect on-and-off with good ol' STEP enhancer. Does anyone have any other ideas as to what could be occurring here?


Seth Hillaker
- Michigan, USA

May 26, 2022

! We identified the problem originating between MPN and electrolytic chrome pre-dip. Here are things we have attempted:

pH low in MPS
pH high in MPS
Carbon treat MPS
Permanganate treat MPS
Low current MPS
No current MPS
High current MPS
No current chrome pre-dip
High current chrome pre-dip
Decant chrome pre-dip
Add STEP enhancer to MPS

The addition of the STEP enhancer to the MPS (causing the nickel to become more noble and risking white wash) has been a quick fix as of late to eliminate this iridescence. The sustainable long term fix was to change out anodes in the MPS. Has anyone else been able to address this issue another way?

Seth Hillaker [returning]
- Michigan, USA

(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:

Chemicals &
Consult'g, Train'g
& Software

About/Contact  -  Privacy Policy  -  ©1995-2024, Pine Beach, New Jersey, USA  -  about "affil links"