In my opinion, one of the most difficult joints to make is a miter joint. Although they are very attractive, they have almost no inherent strength, and require a high degree of accuracy to get all four corners of a box or frame to meet without gaps. To ensure that they remain closed, I use a spline of some design to strengthen the joint.
A number requested additional information on the Miter Spline Jig I use when making boxes. I can’t take credit for the design of this jig, but for the life of me, I can’t remember where I got the idea; perhaps a magazine or maybe a woodworking buddy.
It’s very simple in concept; a carrier that allows me to pass the mitered corner of a box or box lid over the table saw blade at 45 degrees. I think the close-up pictures speak for themselves. The jig is crudely made, but the right-angle is dead accurate. I’ve been using this for about four years. Perhaps someday I will make one that looks like it belongs in Shop Notes; NOT. LOL
Here I have just cut two spline slots in the four corners of the previously glued up box body. The blade is tilted to ten degrees and the box was flipped so that the slots angled in opposite directions. The splines will be cut from American Maple and will be one saw curf wide. I will also use American Maple to make the trays that will fit into the box – but that’s a few blogs away yet.
A close-up of the spline slots.
-- CanuckDon "I just love small wooden boxes!" http://dpb-photography.me/