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Pitting problem in Sulphamate bath

2007

Hello ,
We have set an electroforming system with Nickel Sulphamate . Our variables are these:

Nickel Sulphamate : 600 g/l
NiCl2 : 5 g/l
H3BO3 : 40 g/l
60 °C

First before adding any additives I used the bath like this to see the results. I have taken a matte nice surface except , a lot of holes (pits). They are like shot by a little gun. They are more intense near edges.
Then I wanted to attain a little shiny surface. In order to do this , I added 0.4 g/l saccharin. But then the deposit became so hard and fragile , and the metal uniformity was disrupted. Now I am taking a deposit which is excessively shiny , comes with a lot of pits , breaks when it is bend even a little .
I have 3 commercial additives : Nickel carrier , nickel brightener , Nemlendirici (I wrote it in Turkish . I though if it means wetting agent because in Turkish "nemlendirici" means "humudifying".
I need help on this subject . I would be so glad if you helped.

Thank you ...

Özüm Safaoðlu
plating shop employee - Turkey

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First of three simultaneous responses --

Way too much saccharin! The biggest problem is lack of agitation, with air agitation being the easiest. The next problem is not enough anti pit (wetting agent) Check with your vendor to find out how to check this and to make proper additions. If you add air agitation, you may have to switch to a wetting agent for air/mechanical or you will have foam bubbles everywhere.

James Watts
- Navarre, Florida
2007

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Second of three simultaneous responses --

I solved the problem ; thanks anyway..

Ozum Safaoglu
- Turkey
2007

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Third of three simultaneous responses --

Your original bath doesn't contain any wetting agent, so I suggest you add some. I am not sure whether your "nemlendirici" is a wetting agent or not, so I cannot comment in it. The type of wetting agent will depend on your type of agitation, but one of the simplest is sodium lauryl sulphate - this can be bought through any reputable chemical suppler. Other ones include sodium lauryl ether sulphate, sodium lauryl sulphonate, sodium dodecyl sulphate. You will need about 2ml/l or 0.5g/l depending on if they are solid or liquids.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2007