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Cleaning copper tubing before matte tin plating

I am plating copper tubing with Matte Tin. Having cleaning issues. We have tried several cleaners, soak cleaners and electrocleaners. Combinations of cleaners and acids/acid salts but we still get water breaks and skip plating. The only way we can get good parts is to hand wipe them with MEK prior to racking them. While they don't have to be wiped very much just a quick wipe seems to work it is obviously not very productive. One would think that since it comes off very easy with MEK that there should be a way to get them clean in the regular process. Any ideas. Thanks!

Johnny Rose
Plating Shop Owner - Grand Prairie, Texas, USA
July 17, 2010

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July 24, 2010

When you say that you have tried various cleaners and acid salts separately and in combination. Have you done this on the basis of a supplier recommendation? Has the supplier of the cleaners and acid salts looked at the parts, reviewed your process parameters (time, temperature, current, rinsing, etc) and taken samples of the parts to attempt soil removal in their lab before making product recommendations? If not find another supplier! A quality supplier will find which products and or process cycles will work on a particular soil (at least in the bench test phase) and will evaluate your process.

Gene Packman
- Great Neck, New York

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July 27, 2010

It sounds like there are surface imperfections or porosity that have entrapped oils that are not removed by your current cleaning procedures.

If solvent wiping solves the problem, then vapor degreasing would also. If this is not a possibility, then there are two more things that you could try.

One is a low temperature bake before cleaning to try to dry out the oils, another is a short, low voltage reverse current etch in acid. This will dissolve a little copper and give you a fresh surface to plate on.

Lyle Kirman
consultant - Cleveland Heights, Ohio