Bronzing

In electro-plating the deposition of a mixture or virtual alloy of copper and tin. In general manipulation it resembles the operation of depositing gold and silver alloy, or of bra ing. For bronzing the following bath is recommended: Prepare each by itself (a) a solution of copper phosphate and (b) a solution of stannous chloride in a solution of sodium pyrophosphate. For a, di olve recently precipitated copper phosphate in concentrated solution of sodium pyrophosphate. For b, add to a saturated solution of sodium pyrophosphate solution of stannous chloride as long as the precipitate which is formed di olves. Of these two solutions add to a solution of sodium pyrophosphate which contains about 1.75 oz. of the salt to the quart, until the precipitate appears quickly and of the desired color. For anodes use cast bronze plates. Sodium phosphate must be added from time to time; if the deposit is too light add copper solution, if too dark add tin solution. (W. T. Brannt.) 90   STANDARD ELECTRICAL DICTIONARY.