Making a Shop Moisture Gauge
T
HE DRAWING BELOW SHOWSa simple gauge you can make to
give you a general idea of the relative humidity in your shop.
The gauge will graphically show your customers how wood moves
and why you build the way you do. For the gauge to work properly,
the 20-in. wooden expansion arm must be sliced off the end of a wide
panel or glued up from flatsawn segments, as shown. Movement of the
gauge will be more dramatic if you pick a wood species that has a
large tangential shrinkage percentage, such as beech, sugar maple, or
white oak. If you have access to a moisture meter, you can scale the
gauge numerically.
—JOHNSILLICK,Gasport, N.Y.
Editor’s Note: For formulas on predicting wood movement, check
Bruce Hoadley’s book Understanding Wood(The Taunton Press, 63 S.
Main St., Newtown, CT 06470).
SHOP SETUPEndgrainFasten only at
this end. Leave
remainder of arm free
to shrink or expand.
Expansion arm, 3
⁄ 4 in. x 1^1 ⁄ 2 in. x 20 in.
PinFulcrum