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Q&As since 1989


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Manganese phosphating of piston rings

I'm a Chemist and I work in a electroplating factory. We make steel rings for pistons. In our rings we apply a coating of manganese phosphate. The problem of the process is that some white residue is formed in the phosphate bath and inevitably dirty our rings. I don't know the origin and composition of the residue. Our bath is prepared with phosphoric acid and manganese phosphate. What process would you suggest to prevent such white residue formation? We are concerned about quality issues.

Thank you.

Carlos Monteiro
electroplating - Cantanhede, Coimbra, Portugal
2004

Home brew phosphate systems frequently lack things like accelerators and stabilizers which make proprietary solutions work a lot better with a lot less problems. Case in point, what is the dollar cost of a 1% failure rate vs the cost difference of the best solution that can be found in your country or imported if required? there are chemists that have literally spent a lifetime tweaking these solutions for optimum performance and should be there to help you with tech service when you have a problem. There are not many freelance chemists for phosphate solutions. Most chemists are owned by the company they work for, so do not get your hopes too high for a definitive answer. They could be fired for a reply.

James Watts
- Navarre, Florida
2004

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Even so; there is no substitute for effective continuous filtration.

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India

2004