Before their final assembly, all Ricco Kühn instruments are painstakingly polished to a high shine. Without additional surface treatments however, the metal would quickly tarnish. Untreated brass can, of course, still look very beautiful. But where fingers come into contact with the instrument, oxidation almost always stains them green. As a basic principle, any surface treatment will protect the metal and leave a valuable instrument looking beautiful for longer. I would now like to describe briefly the advantages and disadvantages of each treatment, and how this can influence the sound.
Lacquering is relatively inexpensive and easy to apply to a range of metal alloys. It allows the ‘natural’ color of the instrument to shine through. As the lacquers we use today are applied in a very thin layer, the effect on the sound is minimal. In thin-walled hard bells, some of the overtones could possibly become somewhat muted, but in practice this is hardly audible. From a mechanical aspect, modern lacquers are very durable.
Silver plating is a highly robust and durable surface finish. Repairs to silver-plated instruments can usually be carried out without causing any damage. Silver plating can influence the sound more than lacquering or gold plating. Depending on the thickness of the plating and the properties of the metal, the timbre is somewhat darker and fuller in p and mf, and brighter and richer in fortissimo.
For most models of trumpet, silver plating improves the sound.
Gold plating is the finest surface finish. Gold-plated instruments are chemically insensitive and therefore almost totally resistant to perspiration and saliva. This means they look valuable and shiny without the inconvenience of having to polish them all the time. From a mechanical aspect, however, gold-plated surfaces are more delicate than silver-plated ones.
Dents can be carefully hammered out, but soldering is not really possible without causing some degree of damage. Gold-plated instruments have a more velvety, noble sound, which is richer in overtones. Pure gold plating has an almost neutral effect on the basic sound and blowing resistance.