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  for Metal Finishing since 1989
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How To Tarnish Steel

I refinish furniture and have several hinges I need to alter. They are made of mild steel. How do I tarnish unplated mild steel? I have been told an acid bath would do the trick. If this is correct, where would I purchase the items needed for the bath and how would I perform the bathing process? I know how to rust steel, but need to know how to tarnish or antique it in some way.

Todd McLemore
- Houston, Texas
2003

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Black (dark gray)for iron:
2-20 gm tannic acid ⇦this on eBay or Amazon [affil links]
1,5 gm phosphoric acid
1 lit water Can be brushed or sprayed on well degreased object.
Can be wax,oil or lacquer finished!

Good luck!

Goran Budija
- Zagreb,Croatia
2003

I have used myradic acid many times to rust steel. Any type of acid will only oxidize or rust steel. I am still looking for a good way to tarnish. The only procedure I have been ably to find that works is quite labor intensive. I recently tarnish some mild steel tube by painting it with a grey latex spray paint. After the paint had dried I then took a fine wire cup wheel in my 4.5" grinder and rubbed the paint back off. The trick is when you grind the paint back off you can't use the edge of the wheel. You need to use the cup completely flat. If you go too far with the grinding you will rub the tarnish off as well.

Brian Guse
- Longmont, Colorado, USA
2005

Ed. note: make that "muriatic acid ⇦this on eBay or Amazon [affil links] " we presume.

Put the steel in a potato if it is small like a knife and it will tarnish nicely. Put it in a watermelon if it is larger. The watermelon takes longer but works just the same. Hope this helps.

Matthew Rife
- denver, North Carolina
2007