MAPLE
Botanical Background:
The maple family, Aceraceae, consists of only two genera; Acer (the
maples) and Dipteronia, a small genus containing only two species native to
China. The remaining 150 or so species are all maples and they are spread
throughout the Northern Hemisphere in both the New and Old Worlds. They are
predominantly deciduous trees, preferring moist, temperate climates with
pronounced seasonal change…although a couple of species range slightly below
the Equator in Indonesia. In terms of diversity, China possesses the greatest
number of species with about two thirds of all the maples. Only about a dosen
maples are native to temperate North America, but the United States and Canada
dominate world trade in the export of maple lumber and plywood veneers.
The American Maples:
Of our dozen native species, only 5 or 6 are commonly available as lumber
sold through commercial outlets. However, the trade traditionally has segregated
them into only two categories: hard maples and soft maples. Hard maple is
provided by only two species native to the northeastern and midwestern states:
sugar maple (Acer saccharum) and black maple (Acer nigrum.) While all of our
other native species are classed as “soft” maples, there is considerable
variation in the density and other average properties of the woods as indicated
in the following table:
SPECIES: DENSITY: SHRINKAGE:
Specific gravity Radial Tangential T/R Volumetric
Hard Maples:
Sugar 0.56 4.8% 9.9% 2.06 : 1 14.7%
Black 0.52 4.8 9.3 1.94 14.0
Soft Maples:
Red 0.49 4.0 8.2 2.05 12.6
Silver 0.44 3.0 7.2 2.40 12.0
Bigleaf 0.44 3.7 7.1 1.92 11.6
Two other species sometimes are seen in the commercial lumber trade;
striped maple and boxelder. The wood of striped maple is very similar to that
of silver maple and seldom segregated. However boxelder is sufficiently
different to be of special interest to turners in that it is the finest
textured of the maples and turns beautifully. With a specific gravity of only
0.42, it is also the softest of the soft maples. But perhaps it’s most stunning
feature is that it sometimes develops beautiful, coral pink spalting, making it
look almost like marble when the figure is exposed on a curved surface. The
primary reason this species is not more appreciated in other cabinetmaking
pursuits is that it is relatively weak, tends to be a little brittle and has
rather poor stability. At 14.8%, its volumetric shrinkage is the highest of the
maples, but its rather low T/R ratio of only 1.90 makes it less prone to
distortion than are most of the other maples.
Special Features;
The maples have a number of features that make them outstanding woods for
turning. They are all fine textured, diffuse porous woods with very even
texture. They also produce some outstanding special figures, such as
bird’s-eye, fiddle-back and quilted, as well as unusual variations in color
caused by spalting, such as in boxelder and ambrosia maple. Another important
feature of the maples is that they are chemically friendly in that they are
among the least toxic of all species. Although toxins can be introduced via
spalting, ordinary maple is perhaps the best and safest wood to use when making
food or toy related items.
Information developed by Jon Arno or Mark Kauder and posted by Mark on www.woodcentral.com . Mark has graciously given East Texas Woodturners permission to add the write ups to our site. Thanks Jon and Mark.