Metal finishing Q&As since 1989

-----

Cleaning wire with calcium/moly stearates

 

Our company nickel plates wire products and the wire is currently drawn down to size with die boxes using sodium stearates. It has been proposed to change to a calcium/molybdate stearate material because it is easier to drawn the wire with this. We have heard from some that this material is much harder to clean with alkaline cleaners. Has anyone had any experience with a material such as this and are there any immediate problems that come to mind in using it before plating?

Thanks,

Chris Ballew
- Newport, TN

---

You are correct to investigate the ability of your present line to clean a new drawing compound. You may need higher temperature, different surfactants, etc. to satisfactorily clean the wire.

  
Tom Pullizzi
Falls Township, Pennsylvania
 

---

 

This takes me back to my happy days in the labs at school.

Sodium stearate is soap, add it to hard water and you get scum formed which is calcium stearate which is less soluble.

Thus you are going from a water soluble contaminate to a almost insoluble contaminate.

I would say talk to your people about this as you may have big problems.

Martin Trigg-Hogarth
surface treatment shop - Stroud, Glos, England

---

Cleaning a calcium stearate 'coated' surface is particularly difficult. Many have especially switched from calcium to sodium stearate to avoid these difficult cleaning problems. If, despite all, you would prefer to continue with this, try a very strong alkaline cleaner with high complexant concentration at high pressures and temperature. Such product could dramatically interfere in the water treatment afterwards.

Best regards,

Peter Piessens
- Bertem, Belgium