Common persimmon (Diospyros virginiana) got its Latin name from the wonderful fruit it produces…the name is from the Greek god Zeus and means “fruit of the gods.”
Caution: It is only after the first frost that the fruit (orange colored) is tasty; earlier-picked fruits will really pucker your lips! It is one of two species in the U.S. in the ebony family. The tree itself is not real common, so sources of this wood will require some effort; smaller mills often have some persimmon logs. Its properties, however, make the search worthwhile.
Persimmon wood is very tough and very hard, and is especially noted for its ability to retain a smooth surface (smooth and a high polish appearance) even after long usage. The desirable wood of persimmon is the sapwood, which is white in color in the tree but turns to a grayish brown color when exposed to air.
Persimmon sapwood was the preferred wood for spinning bobbins, weaving shuttles, and thread spools. It was often used for pool and billiard cues. But the most important use was for golf club heads. Today, we might find this a good wood for strong handles, or for uses where distinctiveness is a key factor.
The heartwood, which is found in small amounts only in older trees, is dark brown to black, and is not what most users are looking for. However, the heartwood is an excellent substitute for ebony. (Although the wood looks like black locust, it does not fluoresce under black light.)
Processing Suggestions And Characteristics
Density. Persimmon has a density of approximately 50 pounds per cubic foot when dry, which is heavier than almost all other North American species, except for several of the true hickories and live oak. When green, the lumber weighs over 7 pounds per board foot; when kiln dried, the lumber weighs a little over 4 pounds per board foot at 7 percent MC.
Drying and Stability. Persimmon is difficult to dry as it is prone to surface checking. If 4/4 through 6/4 lumber is treated like it is 8/4 white oak, then it can be dried without much trouble. Lumber 8/4 and thicker will require slow shed drying for 6 months or longer before it can be put into the kiln.
Overall, persimmon has very high shrinkage, 9 percent shrinkage from green to 6 percent MC. This is more shrinkage than in oak (7.8 percent) and other common hardwood species (6 to 7 percent)!
To achieve the whitest color, for many years a golf club head manufacturer used rapid radio frequency drying.
Shrinkage and swelling in use are common when the MC changes. For this reason, most uses of persimmon are for products, such as dowels, that would not become defective if there is a small size change.
Gluing and Machining. As might be expected with such a dense species, the wood does not glue easily. In other words, the species requires everything to be perfect, MCs, flatness, pressure, and so on. Gluing surfaces should be machined and glued within 15 minutes.
Machining is also difficult due to the density. Tools must be very sharp. High speed steel is probably a better choice than carbide, even though frequent sharpening is required. Nonetheless, once machined properly, the surface is excellent.
Strength. Persimmon is very strong, stiffer and stronger than all common hardwood species, except hickory. The strength (MOR) at 12 percent MC is nearly 18,000 psi. The stiffness (MOE) is 2 million psi hardness is 2300 pounds; this hardness is outstanding. For comparison, hard maple’s MOR is under 16,000 psi, MOE is 1.83 million psi, and hardness is 1450 pounds.
Color and Grain. Persimmon is mostly sapwood. The sapwood is white when first cut but ages quickly to a grayish brown. The grain is obvious but is not stark or dramatic.
Oftentimes, persimmon turnings are tumbled together (using a large drum at only 3 rpm) as a final polishing treatment. Even without wax added to the tumbler, the surfaces are very smooth and appear polished. Sanding or polishing with very fine sandpaper achieves the same results.