配方类型：	METALS AND THEIR TREATMENT
配方说明：	Cleaning Old Coins
配方组成：
配制方法：	Use a small stainless steel pan as an anode and the corroded coins as cathodes. The pan is filled with a 2% solution of sodium hydroxide, and the coins dangle from alligator clips into the bath. When a direct current from a small battery charger (12 volts, 950 milliamps) is applied across the circuit the coins literally clean themselves.

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