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Scale Problems on Steel

We need to remove weld scale and glass from steel parts that have a particularly bad looking weld. Our normal treatment uses 2 mins in a 20% Sulfuric(Cathodic) to help remove the scale prior to plating with Nickel. We have tried the following without much success: Longer immersion times in the 20% Sulfuric, Alkaline Permanganate Solution @100g/L at 120 degrees F, and media blasting. Media Blasting works every time but we are not set up to run this kind of volume I am looking for other alternatives.

J. Ott
plating shop - Hbg, Pennsylvania
2007

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First of two simultaneous responses -- 2007

Try pickle paste (brush-on) from a welding supplier.

Alkaline permanganate scale conditioning is usually performed at higher temperatures, 160 to 180°F (71 to 82°C).

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.

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Second of two simultaneous responses -- 2007

Gentleman,
If usage of Cyanide is not restricted,you can try using the following composition in Periodic reverse current cleaning,10 seconds forward and 20 seconds reverse for a period of 15 mts.

Sodium Cyanide 60 gram/litre and Sodium Hydroxide 60 gram/litre.
Temperature shall be ambient.

SHANKARANARAYANAN N
- Bengalooru, Karnataka, India