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Ring Test for Wetter Content

Back in the day I remember running a crude surface tension test on nickel plating solution using a copper wire ring and dipping it into the plating bath, slowly removing and timing the seconds until the bubble burst. Can this be found in any specification or is anyone else using this approach for on-line, rough determination of wetter content? If memory serves me right, 5-15 seconds was required. If under 5 we started to get pits and above 15 deposit became overly stressed.

Milt Stevenson
Job Shop Plater and Owner - Syracuse, New York
May 20, 2008

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May 21, 2008

I have never seen a spec for this method, but used one similar to what you mention. I made a series of rings from 0.030 stainless weld wire (TIG welded) that were from 1" in dia to 4" in dia in 1/2 inch increments. By trial and error, I found that my anti pit was correct if it would hold on a 2" ring but would not hold 10 seconds on a 3 inch ring.
Much later, I got a stag and did it professionally, but I gave the rings to production to do a daily check and to call me if it failed.
The reason that I got the Stag was I switched the wetter on the nickel line from SNAP to SNAP A/M. The rings do not work well if the wetter has an antifoaming ingredient.It drove the nickel to a terribly compressed internal stress. Have you seen nickel that looked like corn flakes.

James Watts
- Navarre, Florida