Butternut (White walnut)
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Butternut (Juglans cinera) is a tree that is more valuable for its sweet oily tasting nuts than for its lumber. In fact, the genus name “juglans” means “nut of Jupiter.” The nuts (oval shaped, compared to the round walnuts) are very tasty, having a sweet, buttery taste, hence the common name.

Regiments of Confederate soldiers used butternut dye, obtained from the nuts and the rinds, to color their clothing, explaining why the were sometimes referred to as “Butternuts,” a somewhat derisive name.

The tree, found from Canada and the U.S. east of the Mississippi River, has a life span of less than 75 years. In recent years, a fungus (bark canker) has been attacking the trees at young ages, with extensive death occurring. Eventually, this species will be on the endangered species list.

In the spring, the tree can be tapped for excellent syrup.

Butternut wood is very stable with little tendency to warp or crack in use. Two important past uses of the wood have been for church altars and for wood carvers, especially for duck decoys. Today, carving uses continue along with furniture, curios, millwork and paneling. The softness limits its use in situations where impact risks are high, such as a desk or table top. Although supplies are not plentiful, this can be an excellent show wood where moderate character is desired and strength is not critical.

 

Processing suggestions and characteristics

Density.

Butternut is quite low in density for a hardwood, averaging approximately 26 pounds per cubic foot. Kiln-dried lumber weighs about 2 pounds per board foot.

Drying.

Butternut is very easy to dry. Rapid drying assures that blue stain will not occur. Rapid drying at cool temperatures also helps to prevent enzymatic oxidation stains that result in pinking or graying stains.

Shrinkage in drying is only about 5 percent. Warp is minimal.

Gluing and Machining.

This species is noted for excellent gluing. Glues are quickly absorbed by dry wood. So, to prevent a starved joint, pressure needs to be applied immediately after glue spreading, or the spread rate should be increased. Avoid drying the lumber under 6.5 percent MC to prevent increased gluing problems.

Machining of butternut is somewhat difficult due to its low density, unless one is used to machining such material. Low moisture (under 7.0 percent MC), aggressive feeds, and very, very sharp tools will lead to success. The finished surface is very lustrous, even after it is finished.

Stability.

With the low shrinkage and straight grain, the wood is extremely stable in use.

Strength.

Unlike its sister species, black walnut, butternut is quite weak. The strength (MOR) is 8100 psi (hard maple is nearly twice as strong). The stiffness is also low compared to many other hardwoods; MOE is about 1.2 million psi. Hardness is only 490 pounds; maple is nearly three times harder.

Color and Grain.

Butternut has a narrow band of white sapwood, but most lumber is heartwood which is light brown. The wood has a nice, unique luster to it when sanded.

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About the author
Gene Wengert

Gene Wengert, “The Wood Doctor” has been training people in efficient use of wood for 45 years. He is extension specialist emeritus at the University of Wisconsin-Madison.