How to Make a Violin String

Making your own violin strings is a challenging project.

Making violin strings depends very much on the type of material used. To make any of these types of strings, you will need special equipment for each kind. Violinists often prefer so-called "cat gut" strings, which are actually made from sheep intestines. Today, strings are made from other materials, such as steel and perlon, but these are always compared to gut strings that violinists used before modern methods of string making.

Things You'll Need

• Container of sheep intestines
• Cold water
• Stainless steel containers
• Metal scraper or dressing machine
• Stainless steel or rubber table
• Salt/water solution
• Alkaline solution
• Splitting horn
• Sheet of black plastic (or other material)
• Hydrogen peroxide
• Humidifier
• Twisting bench
• Centerless grinder
• Colored paper
• Metal ball

Instructions

Dressing the Materials

1. Get sheep intestines from a butcher, which will arrive in stainless steel containers. Make sure the "casings" (to become strings) had been cleaned and preserved while still hot.

2. Open the container and immediately soak the preserved casings in cold water to soften the submucosal membrane of the casings. Remove both the outer serosa and the submucosal membrane. With a metal scraper, the serosa can be removed, while a crushing action also liquefies the submucosa membrane and causes it to drain. Today, machines are used for this hard step, in which case you would feed the casings through the machine.

3. Sort the casing on a table of stainless steel or rubber. Fill a section 8 to 12 inches long with water to check its diameter. A "narrow" casing will expand to 18 mm or less, "medium" between 18 and 22 mm, and "wide" between 20 and 24 mm, and anything beyond is considered as "extra wide." You will find that there is a wider section and a narrower section of the intestine, and the narrower (or "second set") is more ideal for making strings because of the structure. The second set will be 8 to 15 yards long, usually 18 to 20 mm in diameter. Once selecting the casings, group them together (called "hanks") and store them in a salt solution.

Making and Polishing the Strings

1. When ready to make the strings, wash the salt out of the casings with an alkaline solution. Lay the casing across a "splitting horn", a device consisting of a curved mandrel with a blade crossing the plane at a right angle. Observe two sides of the gut, one that is smoother, and one that is rougher. First, split the gut at the divide with the blade--for violin strings, you will want to make strings from the smoother, or "right," side. Continue cutting the length of the smooth side into small "ribbons," with about the diameter of 1 mm.

2. Take each ribbon and put it into an alkaline solution, which must be changed four times a day and closely monitored. Also, scrape the ribbons once a day. The pure gut has a white translucent color, and this process (which will take four days) works out any imperfections. Use of a black background, beneath the ribbons will help you distinguish the imperfections from the actual gut.

3. Whiten the ribbons by immersing them in a water solution with hydrogen peroxide for four hours. Let the gut rest overnight.

4. Take the ribbons to the twisting bench, consisting of a head stock of spindles on one side of the bench and a bank of hooks on the other, or the "lazy end." To make a violin e-1 string, attach three ribbons on the hooks of the twisting bench; for a violin a-2, attach eight ribbons; for a violin d-3, attach fifteen ribbons (these are averages). Count out the ribbons, and tie them with a string loop that is connected to the spindle of the twisting bench. Comb the ribbons with fingers to straighten them and evenly distribute the tension. Tie the other end of the bundle to the other string loop, which is attached to a lazy hook. Allow a slight sag in the length.

5. Twist the string. Do so in a damp environment, using a humidifier. Increasing the twist angle decreases the strength while the flexibility increases. Twisted fibers tend to reach maximum strength at about 17 degrees. As the string is twisted, water will drip from between the ribbons, so you will need to twist the string tighter, and then wet it on the outside. Repeat this process over the course of two or three days until the string is settled and stable.

6. Polish the string with a centerless grinder; the mechanism consists of two grinding wheels, with one pulling the string at a steady rate, and the other being an abrasive stone. The machine ensures that the string becomes a perfect cylinder. Wrap one end of each string with special colored paper for reference of the string type, and the other in a loop around a small metal "ball" which string players use to anchor the string to the tailpiece.

Tips & Warnings

• At the slaughterhouse step, do not let the organs cool, or many problems will result that will cause a poor quality string.

• If the alkaline solutions used are too strong or too warm, the gut may break down. Err on the weak side.

References

• Making Gut Strings
• How to Make Violin Strings