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How to get shiny stable surface on brass until we can get it into nickel plating

Q. We've been using H2O2 at 50% for some time before plating of Nickel in order to get shiny plating on Continuous Running Metal Zipper Chains.

We are using H2O2 together with Sulfuric Acid + Water by making it hot till boiling however the life time of this solvent is not that much long 15 minutes latter H2O2 loses its power and we do as much as we can only in this period of this. The life time is one question. is there any way to make this life time longer?

Another question is even if we get very shiny surface on chains after this process the chains are getting quickly dark by oxidation by air or in water. Even we have tried to dry it quickly or put it in to a water with a little sulfuric acid, still we could not succeed to get any result on that.

We cannot take these zipchains quickly to the plating bath since this is a continuous system of bath and it carries the chain slowly and the beginning of 200 mtrs is much shiny than end part.

I really do not know what to do to get a shiny surface before plating

Rojen Baltas
manager in zipper Factory as R&D - Istanbul, Turkey
March 10, 2010

A. Hi, Rojen. There are proprietary stabilizers for H2O2 that help counteract this rapid degeneration and allow it to be used with sulfuric acid as a practical bright dip for copper and brass. I am not sure of their composition and whether they are protected by patent. However, I do know that you can buy them.

Depending on your environmental situation, the most practical way to maintain the bright dipped look for a while is to dry the zipper in solvent rather than water. This is done in a system which is basically the same as a vapor degreaser.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 10, 2010