Music is an art and a passion. It is something that can be enjoyed by almost everyone, and created by almost everyone. It affects our thoughts and affects emotions, but how does it work? What chemistry lies behind the beauty of music: behind the strings of a guitar and the head of a drum; behind the bell of a trumpet and the reed of a saxophone; behind the bow, gracefully gliding across the strings of a violin? In order to figure that out, this post will delve into the wonders and chemistry involving the construction of musical instruments, focusing specifically on the corrosion of guitar strings.
Before we go into the details, let’s talk about guitars. Guitars can be generally grouped into the following categories: acoustic, classical, and electric. Each type has a standard count of 6 strings. However, they also have some distinctions. Acoustic guitars have metal strings, whereas classical ones have nylon strings. Strings made of steel (metal) are usually made of alloys of steel, nickel, silver, and bronze. The different types of metals used in producing the strings are responsible for the tone and the smoothness of the sound of the guitar strings. Metallic strings, for example, have sounds that are more “crisp” than nylon strings, which have a well rounded, warm and soothing tone.
The first guitar strings were made of animals’ tendons. However, these strings were difficult to produce and were easily distortable. As time went on, the material of the guitar strings and guitars changed to minimize the impact of changing temperatures and humidity. Iron-based alloys, nylon polymer coated metal strings, and titanium are used to combat this. However, the major disadvantage of these strings is corrosion, the deterioration of materials from chemical reactions in the environment. A major contributor to the corrosion of metal strings are the sweat glands on a player’s hand which produce oils and salts that are acidic, and are the major cause of corrosion. Other factors, such as the moisture of the air, can contribute to the deterioration of metal strings.
One attempt to stop corrosion was to coat steel string with natural and synthetic polymers. This did prevent corrosion, but it also created a decline in string brightness, thus giving the guitar a less impressive sound. Musicians preferred higher quality sound than corrosion-proof strings.
Nylon string was an innovation that made corrosion and tonal problems obsolete, as nylon strings do not corrode and form sounds that many players enjoy. In this video, you can see the difference in the build and sound of nylon and metal string guitars. Although the sound quality of nylon strings is pleasant, many players still prefer the sound of metallic strings, so new methods had to come into play in order to create corrosion-proof metal strings, such as corrosion-proof coatings.
There are many different coating agents available to minimize corrosion of guitar strings. For example, ClearTone is a coating for guitar strings that has proven to be very effective in resisting water and sweat, as seen here. These coating agents are tested to verify their effectiveness. These tests involve putting strings coated with different materials in a solution of water and other chemicals that are commonly found on hands. Videos of these procedures can be found here, and here.
With Titanium strings and the invention of nylon string and different coating agents, manufacturers have been able to solve the problem of corrosion. This could not have been possible without electrochemistry and electrokinematics. For those that want to see more of the chemistry and math behind corrosion, check out the links on the bottom of this article.