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Nickel Anode Bag Problem (stiffness, covered with crystals)

Q. Currently I am having some roughness problems with the bright nickel-chrome line I work on. On Friday afternoon at the end of the working week I took the anodes bags out of the bright nickel for cleaning to eliminate that as a possible roughness source. Most of the bags have crystals growing on them, of varying sizes but are mostly diamond shaped and clear in colour. Does anyone have an idea what these could be? Are they likely to be contributing to the roughness problem? I can't wash them off. Could these possibly be calcium salts?



Also a couple of the bags had something on them that had roughly the texture of concrete, and was highly adherent to the bag, one patch was grey like concrete but the other was a coppery colour. Any suggestions as to what these might be, and how I could remove them.

John Reid
Plating Shop Supervisor - Brisbane, Qld, Australia
June 6, 2008

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Q. The crystals have been confirmed by our supplier's lab as being either calcium borosulphate or calcium metaborate.

The big job now is getting rid of them.

The good news is, we now use deionised water in the nickel solution to prevent the calcium from building up again.

John Reid [returning]
- Brisbane, Qld, Australia

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Q. We are having real difficulty finding a way to remove the calcium metaborate, as is our supplier. Apparently the usual calcium salt that forms is calcium sulphate, which can be removed by filtering at a high temperature, but apparently calcium metaborate doesn't work that way. I can't even find any information on the solubility of calcium metaborate, regarding whether it has a 'reverse' solubility like calcium sulphate or not. Or is this something common to all calcium salts?

Any suggestions?

John Reid [returning]
- Brisbane, Qld, Australia

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My nickel anode bags are stiff? Why?

Q. I have various size nickel plating tanks ranging from 200 gallons to 850 gallons in volume. I am using titanium mesh baskets with s-nickel rounds and polypropylene anode bags presoaked in a 'Wetter' solution as to not suck it out of solution. My problem is that the bags are becoming stiff after periods of use. I am not sure why they are becoming stiff. Any info is greatly appreciated. I believe my deposition rate is being affected by this.

Joshua Mitchell
Plating shop Supervisor - Erie, Pennsylvania, USA
February 17, 2009

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A. You soak the bags in a wetter solution to remove the sizing from the cloth,(which is bad for your tank) not for the reason you stated. The bags collect trash, some of it is nickel compounds and are green. If the bag is stiff, it definitely is not working properly and your plate rate and tank chemistry will suffer. I used to replace them every 2 to 3 months. Some shops do it more often and some less often. They are cheaper than the problems that eventually arise. James Watts - Navarre, Florida A. Joshua, Nickel chloride (salts) tends to stiffen bags, it becomes worse in the winter when tanks are idle and get cold. It's best to change them as soon as you see a problem. Soaking the bags in hot water once in awhile helps. Mark Baker Fellow Plater - Syracuse, N.Y., USA A. Dear Joshua, I have some questions; i) Can you say what the composition of your bath is? ii) Also, have you done a recent analysis of your bath ? iii) Are you seeing a crystalline substance on your anode bags? iv) Are the bags discolored, and what is the color if they are? v) What is the condition of the anodes? Thanks, Maurice Mason - Danbury, Connecticut