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Poor plating adhesion on steel

Can anybody help when you get a problem that the plating peels away from mild steel material.
The plating is Zinc And clear then the part gets masked then powder painted when we peel the masking off the plating is coming away as well

Garry Campbell
Project Engineer - Glenrothes Fife
2007

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2007

Although there are a few possibilities, the most likely is simply that the parts aren't clean. Are you familiar with the term "waterbreak-free" and the way to observe it and test for it, Garry? Tell us how much you know and we'll try to start from there.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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First of three simultaneous responses --

Another possibility is that the steel is "leaded" AND THAT REQUIRES A SPECIAL PREPARATION. Chlorides and sulphates form insoluble salts on the surface. Use 30%/vol Fluoboric Acid and stay out of Hydrochloric and Sulfuric.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2007

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Second of three simultaneous responses --

Garry
YOU HAVE PEELING PROBLEM.MOST OF PROBLEM TO CLEANING
TRY TO CLEAN YOUR STEEL PARTS SOAK THEN ELECTROCLEAN AND 30-40% HYDROCHLORIC ACID DIP AND RINSE AFTER ELECTRO CLEAN AND HYDROCHLORIC ACID THEN PLATE ZINC.

Popatbhai B. Patel
electroplating consultant - Roseville, Michigan
2007

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Third of three simultaneous responses --

Sounds like the steel is either not cleaned or properly prepared correctly. Please supply full process details, including bath compositions and operating conditions, then a more comprehensive answer can be given.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2007

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Let us know what kind of zinc bath you use. If acid one the reason is rather simple: wrong pretreatment (presume the base metal is mild non-alloy steel). If alkaline - there are lots reasons.
Best regards

Janusz LABEDZ
- Warsaw, Poland
2007