WOOD DOCTOR’S Rx
finishing. It is not uncommon to find that
when such checked wood is exposed to
drier RHs, the wood will shrink and open
the pre-existing checks. The finish cannot handle this opening or movement, so
the finish cracks.
Q:Our main red oak supplier sprays water on his logs during the summer. I have heard that
some don't buy red oak if the logs
were under water because you
can't keep the sap from staining.
Is this true?
Your Premier Source
for Chairs, Casegoods and
Millwork Production Solutions
A:The sap wood in oak, maple, poplar and most other species can stain for
two reasons. First, if the wood dries a bit,
then there is enough oxygen for a dark
blue colored fungus to grow and stain
the sapwood (the white outer portion of
the log). This is called the blue stain or
sap stain fungi. Second, the starches and
sugars in the tree are stored in the sapwood. As soon as the tree is cut, these
chemicals begin to oxidize and, similar to
an apple that has a bite taken out of it,
the oxidation results in a brown, pink or
gray color within the wood. This oxidation
requires warm temperatures.
Bandsawing Done Right.
Particularly suitable •
for cutting rough solid
wood boards with
irregular shapes
and defects.
Utilizes a simple and •
totally unique double
template system. Both
templates are independently controlled, and
allow us to cut two
different profiles on
the same wood piece.
Applying a fungicide to
freshly sawn lumber
can also prevent fungal
damage after sawing.
3-axis CNC
Machining
MDplus+
Milling, drilling, •
mortising with
controlled axis
Able to work on •
up to 5 sides of the
work piece
Especially suitable to •
work parts for cribs,
chairs, tables, etc.
The sprinkling of logs (with the
equivalent of about 2 inches of rain daily)
for several weeks prior to sawing into
lumber can prevent fungal damage by
preventing the wood from drying out.
If there is no oxygen, the fungi cannot
become active. Applying a fungicide to
freshly sawn lumber can also prevent
fungal damage after sawing. However, the oxidation reaction cannot be
prevented in warm weather if the logs
or lumber are stored for any length of
time, even if sprinkled. The discoloration
from this oxidation may not occur or be
noticed for days or weeks later, but the
damage is done much earlier. The oxidation grey stain, also called enzymatic
stain, in logs during warm weather is
controlled by rapidly processing the logs
into lumber and the relatively fast drying
of the freshly sawn lumber. ❮
FOR THE LATEST INFORMATION ON OUR QUALITY
LINES OF SOLID WOOD PROCESSING MACHINERY
AND SYSTEMS...CONTACT US TODAY.
www.solidwoodsystems.com
Phone: 336-884-0700 • Fax: 336-887-6650
Gene Wengert, “The Wood Doctor,”
has been training people in efficient
use of wood for 35 years. He is
extension specialist emeritus at the
University of Wisconsin-Madison.
