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Blacken Metal w/ sulfuric Acid & Copper Sulphate

I build steel furnishings and was looking for an alternative to paint. I heard a solution of sulfuric acid and copper sulphate [on eBay or Amazon] would blacken steels, but have had no success as I do not know the proper mixture. If someone could tell me the proper mixture or suggest a similar treatment I would much appreciate it. Regards,

Tim Blott
- Alberta, Canada
1999

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If this is a hobby, try to find a local finisher that does black oxide on steel. The chemicals are usually applied in boiling caustic solutions, and sometimes in a room temperature bath, but they still require wastewater treatment for disposal.

If you have a larger facility, contact one of the suppliers of chemicals for Technical Data Bulletins on commercial products.

You also have to worry about the decreased corrosion protection of home brew applied blackening agents versus paints.

  
Tom Pullizzi
Falls Township, Pennsylvania