|Fitting a Mortise & Tenon Joint
No matter what method you
use for making a mortise and tenon joint, theres still a good chance that
you will have to do some fine tuning to get a perfect fit.
Undercutting The Shoulders. One of the most common problems encountered
with a mortise and tenon joint is a gap between the two mating workpieces. This
is caused by a shoulder that isnt perfectly square or cut cleanly.
To avoid this problem, I like to undercut the shoulders of the tenon slightly
with a chisel. This allows the edges of the tenon to fit tight to the mating workpiece
when the joint is assembled, see photo.
Removing Stepped Shoulders. Another common problem
when cutting four-shouldered tenons is a stepped shoulder. If I run into this,
I don't try to correct it at my saw. Instead, I come back after and pare them
flush with the side shoulders, as shown in the photo at right.
Undercut Shoulders. To get a tight jointline,
slightly undercut the shoulders of the tenon with a chisel.
Remove Stepped Shoulders. Cut shoulders on
edges of tenon slightly proud, then trim flush.