Balsa Weight for Various Densities

Balsa is one of the lightest woods available, and in many respects has the highest strength-to-weight ratio of any wood - even oak. The chart at the right gives a comparison of a few familiar wood types.

Hobby grade balsa is harvested in the jungles of Ecuador, kiln dried, cut into large blocks, and shipped to the U.S. for final cutting and sanding. Most balsa from hobby shops is in the 8-10 lbs/ft³ realm. The rock-hard stock that nobody wants is sent to the airplane kit manufacturers ;-) The vast majority of the balsa wood I use for building model airplanes comes from Sig, Midwest, and Balsa USA. Other suppliers have materialized in the past few years.

Since the rise of mammoth wind turbines for electricity generation, balsa's use as a core material for blades has caused a severe shortage in the modeling realm. Balsa prices have skyrocketed in the past decade. Substitutes for balsa wood are being frantically sought. See: Wuhan Flu Outbreak Leaves China Short on Balsa for Turbine Blades," "Balsa Shortage Threatens Wind Power Rollout," "The Wood Behind the Wind."

Before being discovered as an ideal source of wood for model airplanes, balsa trees were cut and assembled into raft for floating down the river. In fact, the word "balsa" is Spanish for the word "raft." Balsa has been widely used by the military for air-drop pallets, and in fact, during World War II, balsa wood for models became scarce because the Army Air Force needed it for operations. Bamboo and other reeds were tried by modelers as a substitute wood, but it never could replace balsa.

The charts below for weights of standard hobby shop balsa sheets, sticks and blocks were calculated from a simple formula that takes the density of the of each piece of balsa and multiply it by the volume. For 48" lengths, multiply each 36" value by 4/3 (1.333).

Example:

A 3/16" x 3" x 36" sheet of balsa has a volume of 20.25 cubic inches (in³), which is equal to 0.01171875 cubic feet (ft³). A piece of balsa with a density of 8 lbs/ft³ is the same as a density of 128 oz/ft³. So, to find the weight of the balsa sheet, multiply 128 oz/ft³ by 0.01171875 ft³ to get 1.500 oz. A 48" length would weigh 1.500 oz. x 4/3 = 2.000 oz.

BALSA SHEETS

Weight in Ounces, Density in Pounds/Foot³

BALSA BLOCKS
Weight in Ounces, Density in Pounds/Foot³

BALSA STICKS

Weight in Ounces, Density in Pounds/Cubic³