brass parts

[Richard Schlesinger]

I have a Sanderson full plate camera on which I will be putting a new bellows. The metal parts are all brass, but with a warm gold color (laquer?) on the brass which is dirty and uglied. Brass cleaner/polish takes off the nice color and leaves a bright yellow brass. Does anyone know the process for cleaning and restoring the nice color?

[Mark Sawyer]

Thwew are pickling solutions to turn brass black, but the only process I know for that old patina is known as "time." Skin oil from handling seems to speed it along, but often leaves fingerprints in the patina.

[Donald Qualls]

Trumpets are lacquered, both to give a smoother luster without requiring almost daily polishing, and to preserve the metal against the attack of acidic sweat and skin oils. The lacquer used for this is available from music stores, I think (at least, it was 35 years ago, when I played a trumpet). It's traditionally applied by dipping, but it can be thinned and sprayed also.

[Richard Ide]

Hi

There is information on colouring brass in the (Machinery's Handbook). Published by Industrial Press. A coloured piece can then be lacquered to protect the surface from more change. If you need more information contact me

Richard

[Pete Watkins]

I speak as an ex-clockmaker. Years ago brass parts on clocks and instruments were generally "hot lacquered". This involved either polishing the brass part or "graining"it, i.e. rubbing it in one direction with fine grit emery paper or scrubbing the brass part with emery powder mixed with oil. Another method with old brass was to put the brass parts in a mixture of soft soap and ammonia and heat this up to just below boiling point (apart from killing verdigrease this also removed the old lacquer) and when it had cooled down scrubbing it with emery powder. The brass was then washed in a spirit (often petrol) and left to dry. When the brass had been either polished or grained it was heated up and given a coat of shellac based lacquer with a very fine haired brush and left to cool and harden. If you don't want to polish the brass up and give it a coat of spray cellulose lacquer which will not last very long I fear that hot lacquering is your only way foreward. Various substances were added to the shellac mixture to give it different colours (no apologies for the English spelling by the way). Best of luck, Pete.