Copper plating

As Copper is called the coating metal objects with copper.

Method

For galvanic copper plating a solution of cuprous oxide in potassium cyanide or for cast iron, steel, bar iron is a solution of copper sulphate, Rochelle salt and caustic soda. Iron rusts easily under the copper ceiling and is advantageous leaded front of the copper plating, superficially transformed by hardening in steel or painted with varnish or oil paint and then made ​​conductive with graphite powder. It sometimes produces 1-2 mm thick copper coatings. Iron and steel cover itself when immersed in a copper solution with a copper layer; but if this is to adhere well with some resistance, you must use special tricks.

It is mixed, for example, a concentrated copper sulphate with a little less than half of its volume of English sulfuric acid, immersed in this liquid the steel objects, draws them immediately back out, she rinsed several times with hot water and dry them by rubbing with geschlämmter chalk on a piece of tissue. The copper plating of iron and steel is often a preparatory work to form a base for gold plating or tinning by Ansi Eden.

For copper plating of zinc is heated Weinstein, carbonate of copper and water at 75 ° C, then adds whiting until the roaring stops, filtered, washed from the precipitate, united all fluids and placed in the same previously very bright pickled objects, which in take a beautiful copper-plating a few minutes.

For copper-plating of brass is heated it to the air until it has become blackish, it deletes from in chloride of zinc solution, boiling it is flushed volatile, dries, it boiled in copper- zinc chloride solution ( prepared by boiling zinc chloride solution obtained with annealed copper sheet ) and touches it while on the back with a zinc rod, rinsed, brushed and dried.

Iron can also be plated with copper, when it is heated to incandescence and immersed in the complete exclusion of air into molten copper. Wrought iron plates which are copper plated in this way, can be easily processed without the copper peels off. Since the implementation of this method, however, is associated with considerable difficulties, we coppers usually on wet road. Iron sheets which are galvanized provisionally accept, when immersed in molten, for exclusion of air with carbon -covered copper willingly a copper coating on.

The copper plating of iron and steel in preparation for gilding was already known in 1603, but won the plating itself only since the invention of electroforming practical importance and has been especially designed by Oudry in Auteuil in 1856 for practice.

• Coating