ZoSo357 Posted July 17, 2006 Share Posted July 17, 2006 My coffee grinder currently has an odd buildup of greenish powder looking material over all of the metal surface of it other than the blade (it must be stainless steel) and at the bottom of it there is a layer of brown material similar to the color of iron oxide. The last thing i ground in it was ammonium nitrate, it was about a month ago. it's been sitting in my closet since and when i opened it today, it was in the stated condition. Does anyone have any idea what kind of reaction could have happened? Any help would be appreciated. Link to comment Share on other sites More sharing options...
Mumbles Posted July 17, 2006 Share Posted July 17, 2006 Water absorbtion and subsequent rusting most likely. It happens to me too if I grind hydroscopic stuff and leave it in there for an extended period of time, I just take some steel wool to it. Link to comment Share on other sites More sharing options...
lacrima97 Posted July 17, 2006 Share Posted July 17, 2006 Wouldn't the chromium (I believe that stainless steel is an iron/chromium alloy) in the iron help keep it from rusting though? I thought that was why it was stainless, because it couldn't rust. Idk though, can stainless steel rust? Link to comment Share on other sites More sharing options...
FrankRizzo Posted July 17, 2006 Share Posted July 17, 2006 Sounds like a copper compound. The bowl inside is probably nickel plated brass or copper, so once the nickel coating was compromised, the copper began corroding. Stainless steel is made in a wide variety of alloys, the most common being 304 and 316. Both of these steels are "corrosion resistant" but not rust proof; sometimes iron migrates to the surface of the metal and rusts. The best way to clean rusty stainless is with a plastic abrasive like Scotch Brite pads..never use steel wool which can induce rust. You can re-passivate the surface with nitric acid if it was real rusty. Link to comment Share on other sites More sharing options...
ZoSo357 Posted July 18, 2006 Author Share Posted July 18, 2006 Thanks for the help, I'll most likely go with the steel wool, i doubt it's stainless since it allready built up a green material. I believe stainless steel is a mixture of carbon and iron. Link to comment Share on other sites More sharing options...
lacrima97 Posted July 19, 2006 Share Posted July 19, 2006 Thanks for the help, I'll most likely go with the steel wool, i doubt it's stainless since it allready built up a green material. I believe stainless steel is a mixture of carbon and iron.Carbon and Iron makes steel.Chromium and Iron makes stainless steel. Link to comment Share on other sites More sharing options...
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