Can You Bright Dip Stainless Steel?

We would like to replace the electropolishing step with a non-electrolytic step. Can this be done?


Related Topics:

In the April Plating Clinic, I responded to a question regarding bright dipping of stainless steel. One of our readers e-mailed me and pointed out a much easier solution to the problem than that which was given in my answer. The original question and my response are given below, followed by the additional information. Thank you for writing.

Q. Our company manufactures medical devices from stainless steel wire and tubing. In this process, the parts are ground, cleaned and electropolished. Suitable rinsing is used between each of these steps. We would like to replace the electropolishing step with a non-electrolytic step. Can this be done? V.I.

 

A. There are a number of bright dips and chemical polishing solutions for stainless steel. In my experience, none of these solutions will give the same quality results you obtain from electropolishing.If you want to pursue this, you might try the solution given here. 

ComponentAmount, gal
Nitric acid
Hydrochloric acid
Phosphoric acid
Acetic acid
4
1
1
5

This solution must be used at 155–165°F. The stainless parts must be dipped in hot, 5% sulfuric acid before dipping in the polishing solution. The water content of the bright dip must be monitored very carefully.

Additional Information

Why bother with a home-brew formulation? Formulated bright dips for stainless are commercially available. You can find vendors by searching the PF Supplier Database.

Related Content

Top Shops: Part Inspection Hours Per Week

In the latest Products Finishing Top Shops Benchmarking Survey results for electroplaters, the Top Shops spent 240 hours a week checking part quality and looking for imperfections.