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  for Metal Finishing since 1989
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Pickling of galvanized sheet

I would like to know if galvanized sheets can be pickled? If yes how?

Philip Jacob
- TN, India
2002

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I don't understand why you would want to pickle them, as pickling means to remove the scale from them. The galvanized coating will dissolve far sooner than any scale will.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

I have few galvanised sheet that is damaged or the zinc coating is not uniform. So I would like to know if I pickle these sheet using HCl acid will it remove the zinc coating and also what are the effects it would have on my acid. Is there any other method to remove the zinc coating?

Philip Jacob
- TN, India
2002

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Your acid pickle tank will very easily remove the zinc coating. The zinc will react much faster than steel does, and it will evolve a lot of acid fumes--so make sure you have good ventilation and that there will be no danger or ill results from the very quick and energetic removal process. Any zinc you remove will deplete the acid, of course, but it is quite common to replate zinc plated rejects by passing them through the line again, letting the acid tank remove the defective zinc coating.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

Can I know what is the exact method? is there anything I can add to prevent the HCl to attack my steel? urgent

Jerry Law
ykgi - klang - Kuala Lampur, Malaysia
2006

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Commercial "inhibitors" are available from the suppliers of HCl. If you have an urgent problem please retain a consultant, Jerry. This is merely a public forum, and it may be weeks, months, or years before your inquiry attracts the attention of a good samaritan both willing and able to help. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006