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  for Metal Finishing since 1989
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Conductivity and Throw

If the conductivity of a plating solution is increased(i.e. by adding acid or cyanide), then will the throw of that solution also be increased?

I would expect that solution efficiency would increase due to increasing conductivity since resistance losses would be less, however, usually increased efficiency results in loss of throw, right?

Michael Brewington
- Salisbury, Maryland, USA
2002

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First of three simultaneous responses --

I believe you are right on all counts, Mike.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

 

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Second of three simultaneous responses --

There is throwing power and there is micro throwing power. The first is the mass of metal that you can plate and the second is the ability to plate in tiny crevices and recesses. Sometimes when you increase throwing power you will get a very poor (bad) plate. Speed is not always the optimum.

James Watts
- Navarre, Florida
2002

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Third of three simultaneous responses --

Some years ago elder people (over 40) used to learn by reading pieces of paper glued together called books. They still exist and come in all sort of fashions and specialties. Internet, though fast and powerful still can't beat a good specialized book. About your question, there is also something called polarization that plays an important role in throwing?

Guillermo Marrufo
Monterrey, NL, Mexico
2002

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Efficiency and throw increase with increased conductivity in acid solutions. But in cyanide copper solutions raising the cyanide content above the upper limit will decrease the efficiency because of the tight complexing of copper allowing hydrogen to be plated in preference to copper. the same is true of zinc and Cadmium solutions except it takes a very large excess above the optimum to cause a significant difference.

Don Baudrand
Consultant - Poulsbo, Washington
(Don is co-author of "Plating on Plastics" [on Amazon or AbeBooks affil links]
           and "Plating ABS Plastics" [on Amazon or eBay or AbeBooks affil links])
2002