John's Jaunt
John Johnson
Welcome to the first installment of "John's Jaunt".
The holidays provided me with an opportunity to continue work on my
dining table project. It made its first (unfinished) appearance and saw
use for the Johnson/Yezek family gathering over Christmas. Since then
it has returned to the basement for some repair work and finishing. For
me, most of my woodworking projects are a learning experience in some
new technique. When we have a "blunders" discussion I will share one or
two of the undoings of this table.
Thanks to all of you who have completed and returned the surveys from
the January Ripsaw. There have been numerous useful comments. For those
that have not returned, please take a few moments and either mail or
bring to the February meeting. My goal is to summarize the information
for the February board meeting.
Over the holidays, the Wisconsin Woodworkers Guild was approached by
the Ethan Allen School with an offer for some used woodworking tools
(some 3-phase) and workbenches if we hauled them away. At the January
meeting a number of people expressed interest in bidding on these
tools. Thanks go to Walt Hadcock for stepping up and orchestrating this
effort.
Finally, as many of you know, the January meeting was a low turnout due
to the heavy snow forecast. In the future, meeting cancellations will
be announced on the radio and TV per the enclosed insert.
Inclement Weather Notice
In case of inclement weather listen to the following stations for
meeting notices.
Radio - WTMJ 620
TV - WTMJ Channel. 4
Any cancellation decision will be made by 3pm.
Reflections
January Meeting Reflections
Leila Crandall-Frink
Approximately 35 people braved the winter storm to go to the January
meeting on Wood Movement given by member John McAlpin. John works with
a lumber mill in Watertown, Wisconsin. John braved more of the weather
than the rest of us. We did shorten the meeting so that folks could get
an earlier start on getting home.
John spent time teaching us about the properties of wood. Wood is
hydroscopic, meaning it will soak up water. Wood is anisotropic,
meaning when it gains or loses moisture it swells and shrinks. It also
swells and shrinks differently on different planes. Wood is made up of
cells. A wood cell is made up of cellulose and lignin. Lignin is sort
of the glue that holds the cell together. The only living cells are in
the sapwood portion of the tree. However, all wood cells are full of
water. When wood is cut all cells die but are still full of moisture.
When wood is dried, either by air drying or kiln drying, moisture is
being taken out of the cell. Not much happens to the wood until the
moisture content falls below 20 percent. Under 20 percent moisture
content the dimension of the wood starts changing. As the walls of the
cell dry it wants to collapse and shrinkage occurs.
There are three different planes on a log; the radial plane, the
longitudinal plane and the tangential plane. On the longitudinal plane,
the length, the loss of moisture content does not make much difference
and shrinkage is negligible. On the radial plane, the width, the loss
of moisture can cause a log to shrink 5 percent. On the tangential
plane, or the distance around a log, loss of moisture can cause
shrinkage of 10 percent. The difference between 10 percent shrinkage
around a log compared to the 5 percent across the width of a log
accounts for the cracks that occur during drying.
This tangential/radial ratio is also the reason a log cut into planks
is liable to cup during drying. The amount of cupping varies in
different species of wood. The variance can be plus or minus 2 degrees.
(Writers note: I did not take good enough notes during this part of the
presentation, but there is a difference in drying a log if it is cut
quarter sawn or not.)
The amount of moisture in the cell makes a difference when cutting the
wood. If the water in the cell is above 20 percent, the wood will have
no stress when being cut. If the outside of the wood has water content
below 20 percent, but the inner core of the wood has water content
greater than 20 percent, the wood will spread when cut. If the water
content is less than 20 percent throughout, the wood will pinch the
blade when being cut.
When checking a board with a moisture meter it is good to measure in
about 2 feet from the end to check the moisture. You do no need to cut
a plank to get a good reading. When asked how accurate a moisture meter
is, John said the professional meters were accurate to within 1 tenth
of a percent. He said the one available in hardware stores were usually
between 8 tenths and 4 tenths of a percent. Certainly good enough for
most woodworkers needs.
When asked what moisture content is common for air dried wood, John
said10 percent. But he recommends taking it inside for another month to
dry more. He said veneer wood (plywood) does not have a problem with
moisture because of the thin slices and glue holding it together.
The above information is not necessarily accurate because of this
writerÕs deplorable note taking skills. You can talk to John
McAlpin at
a regular monthly meeting if you want any issues with wood and wood
movement cleared up.
The program was very informative and John did a great job with his
presentation.
Thanks again John.
Raffle Column
Alan Clapp
The February 2nd raffle prize will be a Freud 10-inch 80-tooth saw
blade. This fine finishing blade has been generously donated by Freud
representative Vito Ruggiero who will be our February guest speaker.
Meeting Presenters Needed
The Wisconsin Woodworkers Guild needs you. Do you have a friend or
acquaintance with a woodworking related skill or talent that they would
be willing to share? Give it some thought. If you identify someone, you
can turn that lead over to the Program/Workshop committee and they will
do the work involved in setting up that program or workshop.
We are looking for your ideas and fresh perspective on topics and
speakers. If each one of you could identify one potential speaker, we
would have many new and diverse topics as well as a pool of speakers to
cover the next several years.
There is also a need for help on the Program/Workshop Committee. If you
are willing to arrange a program or workshop and do contact and the
follow-up, if you would help out with these, or if you are willing to
do either a program or workshop (or both), we welcome you and want to
be part of the guild.
Please contact Ken Bahr or a member of the Program/Workshop committee
with your ideas.