COMPONENTS & HARDWARE
By Gene Wengert
QWe are experiencing breakage in walnut cut-to-size chair legs,
somewhat like honeycomb and
straight across. Can you advise?
AWhat you have is “brash wood.” There are three causes. The first is due
to the wood being much lighter in
weight than normal. This is caused
by very slow growth in porous
woods. Light weight is also caused
by the formation of tension wood
(hardwoods) or compression wood
(softwoods) within the tree.
A second cause of brash
wood is decay, such as white rot.
The third cause is if the wood
is squeezed excessively, such as
from a large clamp that was tight-
QWe are having trouble screwing into MDF. What should we do?
AThe lower the MDF density, the greater the chance that screws will
not hold well without special procedures. The higher the density, the
more likely that bulging will occur.
The suggestion is to use a pilot
hole. Use a drill bit diameter that is
85 to 90 percent of the screw’s root
diameter; make the hole a little
deeper than the screw’s length.
Then, you can even put a few
drops of epoxy in the hole prior to
screwing to glue the screw to the
MDF as well as achieve mechanical
strength from the threads. Make
sure to use special MDF screws.
Source: Gene Wengert, “The Wood Doc-
tor,” is extension specialist emeritus at the
University of Wisconsin-Madison. He can be
reached at email@example.com. Read
past columns at WoodworkingNetwork.com
Solving parts breakage & screw issues