Manufacturer and builder 5, 1869
A difficulty is often experienced in causing oil-colors to adhere to sheet zinc. Boettger recommends the employment of a mordant, so to speak, of the following composition: one part of chloride of copper, one of nitrate of copper, and one of sal-ammoniac are to be dissolved in sixty-four parts of water, to which solution is to be added one part of commercial hydro-chloric acid. The sheets of zinc are to be brushed over with this liquid, which gives them a deep black color; in the course of from twelve to twenty-four hours they become dry, and to their now dirty gray surface a coat of any oil-color will firmly adhere. Some sheets of zinc prepared in this way and afterwards painted have been found to entirely withstand all the atmospheric changes of winter and summer.
Ei kommentteja :
Lähetä kommentti