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-----Stalagmometer usage in electroplating
Quickstart:
Plating baths do not operate at 100% efficiency ⇦ huh? but generate hydrogen bubbles which can be problematic for 2 rather different reasons.
• These hydrogen bubbles form on the part being plated and if not dislodged the plating can grow around them leaving 'gas pits' ⇦ huh? -- a problem especially notable in nickel plating.
• In the case of chrome plating a bigger problem is that the very copious amounts of hydrogen which that bath generates bubble to the surface in champagne fizz style, carrying the toxic chromic acid out into the surrounding environment.
For both these reasons platers want to reduce the surface tension so the hydrogen leaves easier and without carrying plating solution out with it.
Stalagmometers are simple glassware devices where the plating solution drips out through a small hole and the number of drops it takes to empty the fixed volume glass bulb reveals the degree of surface tension.
Q. Where to buy a "STALAGMOMETER" for plating bath additive/wetter determination? Also, where to get those different size rings for old Barret SNAP additive determination? (Hey- Don't call me an old-timer!) Thanks, Dave
Dave Kinghorn
Chemical Engineer
SUNNYvale, California
2000
Ed. note: This RFQ is outdated, but technical replies are welcome, and readers are encouraged to post their own RFQs. But no public commercial suggestions please ( huh? why?).
A. Stags-I used to buy them from JPS in Cincinnati, OH. Kocour used to sell them also. Rings-I made my own from 316 SS weld wire, tig welded and polished. Calibrated them in the lab using a Stag. Had a set from 1" to 5".
Also remember using a ring after converting to SNAP-A/M. Ever see nickel plate look like corn flakes on a part. The extreme gross excess of A/M made the plate off the scale on a contractometer test. For the newer folks, the moral is the anti-foamer in A/M prevents you from using the ring test.
- Navarre, Florida
A. The Kocour Co. Inc. in Chicago, Il. has what you need in stalagmometers.
Regards,
- Royersford, Pennsylvania
Q. I have been looking for a Stalagmometer for years and I have not been able to get another one. Chicago is not very convenient for us, but if anybody out there knows where to get one in Europe I would be most grateful.
Thanks
Trudy
- Durban, South Africa
2000
A. Lurex out of Vineland, NJ sells stalagmometers. Good Luck.
Dave Bernardini- Horseheads, New York
A. Just bought a house and contents. Found box with 10 stalagmometers bought from Lurex in Vineland NJ. Have a receipt that states this. I don't know anything about these other than they have 2 bubbles and were purchased in 1988. Would love to sell if anyone is interested.
tim smith <[email protected]>- bridgeton New Jersey usa
Q. How to use a stalagmometer? Please give a demonstration. How do you calculate surface tension from the drops collected?
Santhappan Rema ⇦ Answer?M.G.R.College - Bangalore, Karnataka, India
2004
A. Hi Santhappan
I've seen many youtube videos on the subject, and most are not very good. I think the following is one of the better ones:
Not only are some of the videos poor, they're crazy dangerous! What you SHOULD DO is close off the bottom with a gloved finger and fill the top with an eyedropper. What ever you do, DON'T copy the crazies who show themselves putting the bottom in a beaker of solution then filling the bulb by mouth suction from the top. A mouthful of chromic acid would make for a bad day. Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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Why radius of capillary tube is reduced in stalagmometer & why stalagmometer's tip is flattened.
Ankush Gupta- Delhi
A. Hi Ankush.
I can't really answer beyond saying that it's a precision piece of glassware and a small capillary and flattened tube have been found to produce drops of the right size 🙂
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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