Question

How do we clean silver or brass articles that have got tarnished?

Answer 1

This is a easy way to electrochemically clean up brass, bronze and silver items that are badly tarnished.

I have used it quite a bit to clean up boat hardware and items I have picked up while diving.

The method is simple, and leaves you with a nice clean item without having to do much work.

Brass, bronze and silver tarnish because the metal reacts with compounds in the surroundings. This can be oxygen, sulfur compounds, carbon compounds or chlorides.

The tarnishing actually preserves the metal below by sealing it in, so it can not react further with the surroundings. This is the effect that protects statues, and roof cladding that are exposed to the elements for centuries. Sometimes, however, we wish to remove this tarnishing, like in the example of the bronze handle pictured here.

One way to remove tarnishing is to use abrasives like sand paper or polishing creams. Any such mechanical polishing removes some of the metal every time you do it. This can be seen on old silverware, where the patterns and engravings are usually rounded and have lost detail.

The electrochemical way of removing tarnishing, that we use here, is gentler in this respect. In short terms it turns the surface metal back to its original state by removing only the compounds that reacted with it in the first place.

This is a good way to clean up detailed items, where mechanical polishing could cause damage. It could also save you a lot of polishing work if the metal is badly tarnished.