Frank Street

 

 

2013Spring etch 1

Etched Samples from the Workshop

The object of this tutorial was to show how both copper and silver may be etched using a low voltage power supply and weak nitric acid. Using simple tools and easily obtained materials such as sticky backed plastic film and nail varnish, Penny demonstrated how to create complex shapes and textures quickly and easily. Her method also helps solve the perennial problem of acid leaking down the wires and etching in places you would rather not etch!

Electrical Circuit

Unlike chemical etching this method, (electro etching?), requires an electric current flowing through the electrolyte (in our case dilute nitric acid), to work. In principle, the higher the electric current the faster the etch. The current, and hence the etch speed, is determined by many factors. The most important are:

  • The voltage of the power supply (the higher the voltage the higher the current)

  • The distance between the negative electrode and the work ( the smaller the distance the higher the current)

  • The area to be etched (the bigger the area the higher the current. In this case, although more metal is being removed, the speed at which the etch cuts down through the metal may be slower. )

The diagram below shows how you should connect a system together for etching.