Homemade upright bass guitars have been a part of bluegrass and rural culture for more than 100 years. While designing and building the kind of upright bass seen in most jazz and classical music takes years of professional training as a luthier, designing and building a homemade "washtub" bass can take an afternoon with just a few parts. A resonating tub, a string and a long stick or broom handle, along with several eyebolts and washers, make up the basic parts of a homemade upright bass.
Preparing the Washtub
A homemade upright bass is commonly referred to as a "washtub" bass due to the popularity of using metal washtubs as a resonating chamber. (A resonating chamber amplifies the sound of the vibrating string.) However, plastic tubs, garbage cans and numerous other storage containers can be used. Flip over the metal washtub so the bottom is facing up.
Poke a hole in the middle of the bottom of the washtub using an awl, or drill a hole in the middle of the washtub using a drill.
Clean the bottom surface of the washtub using a damp washcloth or sponge.
Place an eyebolt through the hole in the washtub, with the "eye" sticking upwards on the outside of the washtub. Secure the eyebolt with a washer and nut on the inside of the washtub.
Preparing the Broomstick
Drill a hole approximately 3 inches down from the top of the broomstick, through the center of the broomstick. The hole should be large enough to accommodate the width of the string, but can be larger if necessary.
Smooth and round out the edges of the hole with sandpaper to prevent string breakage or fraying.
Saw a small notch at the bottom of the broomstick in the center of the broomstick. The notch should be large enough to fit snugly into the bottom lip of the washtub.
Drill a hole approximately 3 inches down from the hole created in Step 1 (the hole where the string will go through). The hole should be wide enough to accommodate an eyebolt.
Place an eyebolt through the lower hole on the broomstick and secure the end of the eyebolt with a washer and nut.
Stringing the Upright Bass
Place one end of the string through the upper hole on the broomstick and securely tie the string to the eyebolt on the broomstick. Any secure knot will work. The string should enter the upper broomstick hole on the opposite side of the eyebolt.
Place the broomstick into the rim of the bottom of the washtub by placing the notch created on the bottom of the broomstick onto the lip of the washtub. The broomstick should be placed vertically onto the washtub and sit approximately "straight up."
Cut the string to the desired length with a knife. The string should be cut long enough to tie it to the eyebolt on the washtub and not have too much slack when the broomstick is placed vertically into the rim of the bottom of the washtub. The string can be loosened and tightened by moving the broomstick forward and backwards while placed into the rim of the tub, but the string should be tight enough "at rest" so that it does not sag.
Tie the string to the eyebolt located in the middle of the bottom of the washtub.
Metal washtubs are often used to make homemade upright basses, but countless containers can be used as well. Try experimenting with different containers to see how they resonate.
Acoustic upright bass strings can provide the best sound and strumming experience but also tend to be the most sensitive to snapping if the broom handle is moved backwards frequently, causing the string to become overly tight. Clothesline works well for "washtub" basses because it tends to stretch and is strong enough not to snap easily.