One of the most common questions I get is “should I refinish my Banjo?” There are differing opinions but there are also realities to banjo finish. The new coat of finish will absolutely make the banjo look better but it can also kill the harmonious sound that banjo once produced. The science behind tone and the production of sound will explain why it is just a bad idea to refinish any instrument.
Sound is vibration, all sound is vibration which is picked up by the ear drums. The ear drums actually start vibrating when exposed to these sonic vibrations which is why we “hear”. Every object is constructed in different ways and has a different composition which effects the type of vibrations produced. A thick heavy piece of metal will absolutely have a different sound than say a thin and light piece of metal when struck. Also a piece of rubber will sound different than glass, all objects have different properties that influence what sound they create. It is the ability to vibrate and type of vibration that is the key to producing different sounds.
Have you ever tried to talk underwater? Noises made underwater can still be audible but they tend to be distorted. That is because the water changes the vibrations that are naturally occurring and these changed vibrations are received in a different way than if the item was not being heard underwater. All liquids have this impact on any item when these vibrations are produced and paint is a liquid as much as water is.
Another experiment is to take a glass jar and to start tapping that jar with a metal spoon. The far will have a more high pitched ring when being struck by the metal spoon at first but if you start to pour honey or lets just say paint on the jar the sound of the jar will change to more of a thud. This is because the honey or paint are limiting the amount of vibrations that the jar can produce and also changing the type of vibrations. The limited vibrating currencies are received by the ear differently and that is why there is also a different sound.
When a banjo is refinished this effect will occur in varying strengths. Sometimes there will be little change to an instruments sound because the new finish is not that much different than the state of the original finish. This is most common on newer instruments with little wear and the instrument is being refinished more to change the color and appearance than to change the condition of a more used instrument. In more cases than not an older instrument is being refinished because it does not look good with the worn paint and putting the new layer of paint on the instrument will alter how the instrument produces vibrations.
Keep this in mind before you go spend $500 on a new finish for your banjo. You may improve the look of your banjo will sacrificing the sound.