Chinkless construction, associated with the building of log structures in
Scandinavian countries, eliminates the chinking and mudding so prevalent
in many log buildings. It consists of grooving the under side of every
log in each tier so that it saddles the log beneath, making a close
joint for its entire length. The groove is marked by a tool which, for
convenience, may be called a cabin scribe or a drag (fig. 27).
_Directions for chinkless log cabin construction._---Mark and cut out
the notch just as is done for a round-notch corner. Next, dog the log in
place and scribe, making the additional mark shown by dash line (_X_,
fig. 27). Then, cut to line and, finally, drop log in position.
The scribe is 12 inches long, made preferably of 3/8-inch square steel
or iron bent in much the same manner as the spring in a steel trap; the
two ends are turned down about 1-1/2 inches like two fingers, diverging
to about 3/4 of an inch at the points, and then sharpened with a flat
surface on the inside of the point toward the loop. The loop should be
hammered out thin to provide sufficient flexibility to allow the points
to spread or close easily. A ring is welded around the two halves of the
tool which, when slipped up or down, makes it possible to adjust the
points and thereby prevent any further spreading while the tool is in
use. A link from a small chain, placed over the legs before the points
are turned, will serve the same purpose and, to prevent the points from
springing together, a small piece of wood may be forced between them.
[Illustration: Figure 27.--Chinkless log cabin construction.]
To fit a log, first frame it at the ends and then fit it down to within
about 2 inches of the lower log where the opening is the widest It is
difficult to do a good job of scribing when the logs are too close
together. The scribe must then be adjusted at the point where the
opening is the widest so that, when holding the tool parallel to the
opening, the lower point of the scribe will ride on the surface of the
bottom log. By exerting sufficient pressure, the upper point will score
the top log. Repeat this operation to score the upper log on the other
side. The corner tenons must be marked likewise. Next, turn the log over,
work the tenons down and then cut a =V=-shaped groove to the marked lines
in the remaining portion of the log, using a double-bitted ax. This
groove should be cut deep enough along its center to permit the outer
edge of the groove to rest continuously on the lower log. By removing the
least amount of wood to make the smallest possible groove, the closest
fit is obtained with the least effort.
[Illustration: Figure 28.--Fine example of milled-log
construction--ranger's dwelling, Whitman National Forest, Oreg.]
The principle of the scribe is based on parallel lines, and it can
readily be seen that if there is a hump on the lower log there will
have to be a gouge in the upper one. When the work is done carefully,
the space remaining is negligible. Where an airtight wall is desired,
a strip of plumber's oakum should be laid on the bottom log before the
upper log is dropped into place. If this material is not available, dry
moss is a fairly practical substitute.