WOOD EXPLORER
Gene Wengert
wooddoc@uwalumni.com
Common U.S. hardwood
has character plus:
Syca more
American sycamore (Platanus oc- cidentalis) is widespread through- out the eastern half of the United
States, with a few trees here and there
rather than a large, dense forest. The
trees can be as large as 48 inches in diameter and 100 feet high. In fact, sycamore is
one of the largest hardwood trees in the
forest; it is also very fast growing. Its white
bark results in the name “ghost tree” and
so the lumber is also called ghost wood.
The button-shaped fruit also gives rise to
the name “buttonwood.” In Europe, it is
often called lacewood. Early pioneers settling in the eastern U. S. knew when they
found a sycamore tree that the soil would
be deep and rich.
Sycamore is used occasionally in
high-end furniture and cabinetry but
seems ignored for the most part — a
shame as the wood has more character
when quartersawn than any other hardwood, including white oak. The reddish
hue is attractive too. Perhaps an entire
suite of sycamore might be too much,
but this wood can certainly be used for
accents, trim, wainscoting, paneling
and flooring. Before plastic containers,
sycamore food boxes were common. Also,
the interlocked grain (see machining
section) resists splitting, so this wood was
and is popular for butcher blocks. ●
Processing suggestions and characteristics
Density. The density of American sycamore averages 31 pounds per
cubic foot at 7 percent MC. This is about 3/4 the density of red oak but
is equal to Honduras mahogany.
Drying. This wood dries very easily with little risk of checking, splitting
or warping. However, the wood is prone to developing bacterial infections in the tree that lead to bad odors, water pockets, ring shake (or
separation) and honeycomb when drying — even with mild conditions.
Shrinkage on drying is 6 percent.
Final MCs should be between 6-7. 5 percent. Machining deteriorates
if the wood is too dry; gluing and movement occurs if the wood is too
wet.
Gluing and machining. The wood is easy to glue but requires that
the surfaces be glued soon after preparation to avoid shrinkage and
swelling if the MC changes. Machining can be difficult at times as the
grain is interlocked. This means that the grain varies in direction from
one growth ring to the next. Although this means an enhanced grain
pattern with ribbon strips, it also means that there will be zones in
which planing or surfacing is against the grain (chip-out likely) and then
zones where machining is with the grain. Avoid high feed speeds, dull
knives and high stock removal. Also avoid overly dry material.
Stability. Sycamore is subject to moderate changes when the MC
changes — about 1 percent size change for 3. 5 percent MC change with
the annual rings (tangentially) and 6 percent MC change across the rings
(radially). Some lengthwise shrinkage may be noted at times due to
interlocked grain.
Strength. The wood is moderately strong and stiff — about 65-75
percent of red oak. The bending strength (MOR) is 10,000 psi, stiffness
(MOE) is 1. 4 million psi and hardness is 770 pounds. These are comparable to Honduras mahogany.
Color and grain. The color of sycamore heartwood is light reddish
brown with darker browns found sometimes. Sapwood, which is 5-7
inches wide in the log, is nearly white with, at times, a slight yellowish
tinge. If present, it is nearly white in color. The grain is fine textured but
the figure on quartersawn surfaces is very dramatic. The interlocked
grain also means that the wood resists splitting.
