Letter 34023

Haze on Ni-Cr plating surface [South Korea] 

+++++

Hello.

I am a engineer in plating part at plumbing fixture factory.

I got trouble with Ni-Cr plating on faucet.(brass substrate)

When buffed condition, there was no prominent defects are found on the surface.

After plating, hazed surface appeared and it was parallel with buff directon.

There are so many opinion in our factory.
...Because of not removed buff compound...
...Because of excessive heat when buffed...
...bright nickel layer are not sufficiently deposited... and so on.

Plese give me a help!! Sorry about my poor English.

Jeahyon Joe
trading CO., Ltd - Incheon City, Incheon, South Korea


First of two simultaneous responses -- +++++

Sounds to me like you may have some residual buffing compound that is not being removed sufficiently prior to nickel plating. You don't describe your cleaning process but you might try solvent cleaning the parts prior to your regular alkaline cleaning process.

Also, you could have organic contamination in your nickel. Do you see any evidence of the hazing in your Hull cells? If so, you can narrow it down to nickel pretty quickly. If not, you could have a cleaning and pretreatment problem.

Have you gone a long time since you have dumped cleaners? Are your rinses contaminated? Do you have good quality water?

You have a lot of unknowns present that make it difficult to diagnose your problem. You should go to your chemical suppliers too and have them help you!

Daryl Spindler
Decorative nickel chrome plating - Nashville, TN


Second of two simultaneous responses -- +++++

Dear Mr. Joe,

I think some of your colleagues are right, most of the probability is the buffing compound film that could not be removed during pretreatment and then become haze underneath of your nickel chrome layer. Please check your pretreatment sequences and pretreatment Chemistry whether getting old or not enough.

Are you running new plating line ?

Good luck

Best regards,

Tony L. Chandra
- Jakarta, DKI Jaya, Indonesia


+++++

Thank you for the kind answers.

I think there is no problem in our precleaning process.
We did a simple test.
With new paper buff we tried buffing without buff compound.
And we got same hazed surface in our product.
So we made decision that there was lack of buff compound during buffing.

But still there is a problem.
How can I explain this?
Sharp buff edge can make invisible scratch to brass?
And it can appear after plating?

Dear Tony L. Chandra
It's not new plating line.
Thank you.

Best regards.

Jaehyun Joe
trading CO., Ltd - Incheon City, South Korea


+++++

HAZED SURFACE AFTER NICKEL PLATING.

INADEQUATE CLEANING INCLUDING ACID DIP.

IN NICKEL TANK,ORGANIC CONTAMINATION, PH OUT OF RANGE, CLEANER PERFORMANCE CAN BE CHECKED BY WATER BREAK TEST.

Ajay Raina
Punjab, India


+++++

Hi,

Believe cleaning problem b sorted out, if u see the buffing lines even after plating it means the levelling in nickel is poor and if u r looking for the best levelling go for acid copper with the best levelling organics in acid copper and nickel.

Thanx

Praveen Kumar
    plating process supplier
Mumbai, India


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