Tarnish 610813 206784742 2008-04-19T23:28:13Z Edward321 2096436 rvv '''Tarnish''' is a layer of [[corrosion]] that develops over [[copper]], [[brass]], [[silver]], [[aluminum]] as well as a degree of semi-reactive metals as they undergo [[oxidation]]. It is analogous to [[rust]], but with a slower rate of occurrence. It is mainly caused by chemicals in the air such as [[sulfur]]. It appears as a grey or black film over the metal. <!-- ===Chemistry=== (to be written) --> ==Prevention== {{Refimprove|date=September 2007}} In objects which are primarily for display rather than use, the tarnishing process can be prevented in the long term by [[tinning]], a process by which the reactive substance is coated in a non-reactive substance, such as [[tin]] or [[wax]], and thus protected from oxygen.{{Fact|date=September 2007}} For more frequently used items such as [[silverware]], tarnish is easily prevented by constant use and washing with a mild dish soap.{{Fact|date=September 2007}} ==Removal== "This kitchen version of electrostripping is safe and easy. It's especially useful for removing tarnish from flatware and holloware. In a pot lined with aluminum foil, mix a diluted solution of equal parts of baking soda salt, and liquid soap. A quarter cup of each to a gallon of water is a typical mixture. Set the sterling in the pot; bring the mix to a simmer and allow it to stand for 10-20 minutes as the oxides are transferred to the aluminum, which you'll see is darkened. Throw that away and wash the silver before using it".<ref> (McCreight, Tim. ''The Complete Metalsmith''. Brynmorgen Press Inc., Portland, Maine. 2004.)</ref> Another way to treat tarnish is to put a drop of water and some fluoride toothpaste on a tissue and rub it on the affected metal.{{Fact|date=September 2007}} ==References== {{reflist}} [[Category:Chemical reactions]] {{chem-stub}} [[ar:فقد اللمعان]] [[de:Anlaufen]]