Nickel plating with nickel acetate, nickel chloride, sulfur, saccharin and coumarin

Question

I am a hobbyist trying to learn/apply a nickel electroplating process that I can safely do at my shop. My substrate is a machinable non-stainless steel with unknown carbon content, and I'm looking to do a close variation of the "Watts Bright nickel" formula. I have a 99.9% pure nickel anode, nickel acetate, nickel chloride, boric acid, sulfur powder, saccharin, and coumarin powders.

The formula calls for nickel sulfate; is it possible to simply add the powdered sulfur to the solution, or do I have to use a different process to synthesize the nickel sulfate? If so, can I do so with the materials that I have? Also, the Watts formula does not include saccharin or coumarin, but I know that these chemical additives will increase the odds of a smooth mirror-like finish.

Also, is there a recommended quantity range, or at least a starting point, for these two chemicals for this application? Any insights here from an experienced chemist/electroplater would be greatly appreciated.

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Edit: I was now looking at doing the conventional sulfamate method. How is nickel sulfamate different from nickel sulfate? And I am curious if this chemical is easier/safer, or more challenging/dangerous to synthesize. Also, can I do this synthesis with nickel acetate, sulfur, and/or nickel sulfate?

Answer 1

The formula calls for nickel sulfate; is it possible to simply add the powdered sulfur to the solution, or do I have to use a different process to synthesize the nickel sulfate?

This will not work. Sulfur ($\ce{S}$) and sulfate ($\ce{SO4^{2-}}$) are two pairs of shoes. The oxidation state is different and there is no way that sulfur powder will turn into sulfate during the electroplating.

If so, can I do so with the materials that I have?

It might be possible to heat another nickel salt in sulfuric acid, cool down and wait for the nickel sulfate to precipitate, but I wouldn't do it!

Given that the nickel salts are highly toxic, might cause cancer on inhalation and are harmful for aquatic organisms, I wouldn't mess around with crystallisation and the remaining solution for which you would have to find a safe way for disposal.

It might be much easier to aquire nickel sulfate and set up the bath for electroplating according to the given specifications.

Answer 2

Sulfur powder is usually added to aid in anode dissolution in nickel baths but the percentage is very minimal and is usually incorporated in the anodes during production in 0.2 percentages . This increases the conductivity of the bath the saccharin you mention is a carrier which helps the main brightening agent to create a more dense smooth and less grainy texture hence more bright . Coumarin I have no experience me with but early 70’s plating baths added this . What you can do is add a surfactant like baby shampoo in a few drops to help a smoother appearance or sls sodium laurel sulphate . Nickel sulphate is needed 200 grams per litre as dissolving nick metal in acid won’t give you the conductivity that’s if you have time or money to dissolve a few kgs of nickel metal . Cheers mate!