Copper Nitrate

 

Using a brush to apply the Copper Nitrate creates a marbled effect on the surface of the bronze.

In these videos, Copper Nitrate is applied hot to give the sculpture a mottled blue appearance. Later, Ferric Nitrate is also applied to turn the blue a more apple-green. This is a controlled reaction between the chosen chemicals and the copper in the bronze. Other sculptures take on this type of patina naturally over a long period of time due to weathering.