Mortise and tenon joints
That has a wide variety of applications for doors, frames and the like. The mortise is not chopped right through the wood but is taken through as far as is reasonably safe. If the rail joins the stile near the middle instead of at the end, the tenon can be the full width of the wood. Alternatively, it can be set in slightly at both sides, thus concealing all traces of the mortise. In all tenoned joints the thickness of the tenon should be about one-third that of the wood. Choose a mortise chisel that is nearest to the size.
The tenon should make a hand-tight fit. It should be glued straight from the saw because the roughness gives a key to the glue. If any fitting is necessary use the file to roughen the tenon afresh. In mortising, much of the waste can be removed by first boring with a bit slightly smaller than the mortise width. Be careful to keep the brace up-right.
These are similar to the stub-tenon but with a haunch left at the set-in of the tenon to resist any twisting tendency at the edge. The haunch is entirely concealed when the joint is assembled. In the case of a grooved framework a haunch is always needed to fill in the end of the groove. Note too that the tenon must also be set in at the inside to an extent equal to the groove depth because the grooving automatically cuts away the tenon.
Long -and-short shoulder tenon.
When a frame-work is rebated at the inside the back shoulder must be cut longer than the front one by the depth of the rebate. Note how it is also set in at the rebated edge by the rebate depth since the rebating necessarily cuts away the tenon. A haunch can be allowed as shown by dotted lines, if preferred. It is always an advantage in this type of joint to let the side of the tenon line up with the rebate.
Where strength is of great importance The tenon can be taken right through and wedged outside, the mortise being cut full at the outside.
If the rail is thinner than the stile the tenon need have no shoulders at the sides at all. Instead, a shoulder can be cut at the edge as in the top example at Fig. 3G. Except in the case of slats fitted to a framework it is always desirable to cut a shoulder of some sort; only in this way can the exact rail length be fixed. Mortise and tenon joints.
- A stub-tenon;
- B hunched stub-tenon;
- C tenon with secret haunch;
- D joint for frame with grooved-in panel:
- E long-and-short tenons for rebated frame;
- F through mortise and tenon wedged outside;
- G bare-faced tenons:
- H joint for rebated and molded frame. Haunch can be added;
- I square-shouldered tenon with mitered corner.
Mortise and tenon joints and their application.
- double tenon for wide rails;
- twin tenons Wedged at outside;
- double tenons for drawer rail.
Mortise must be neatly cut because there are no side shoulders to conceal any gaps. When the rail is thicker a shoulder can be cut at one side. The top-edge shoulder is an advantage in any case as it effectually conceals the mortise. Furthermore, it enables the top edges to be rounded without planing away the tenon corners. Mortise and tenon for molded and rebated frame. The shoulders are level since the rebate is level with the lower quirk of the molding, the latter being cut away locally opposite the mortise,
The molding is worked in the solid and the ends mitered, the miter template being used. This is the order in which the work should be done: cut mortise and tenon; work rebate; plane moulding; cut shoulders; cut miter and fit joint. When making a door the shoulder length is taken from the rebate or quirk of the molding, not from the outer edge of the latter. A haunch could be cut at the outside with ad-vantage.
In certain barred doors where the glass is beaded rather than puttied in, the rebate is not so deep as the molding, and this necessitates long-and-short shoulders. With puttied glass there is no difficulty and the simpler joint.
- Square shoulder joint with mitered corner. This is used chiefly for door frames and stands in which the top rail has its lower edge curved. When the shoulder is square there is necessarily short grain at the end of the curve, whereas the miter shown here gives longer grain. There are two ways of making the joint. One is as shown. A line is gauged parallel with the edge and the wood cut away. This enables square shoulders to be cut with the miter at the lower edge. The other is to make the whole shoulder slope.
- Double tenons. For wide stuff the joint is necessary. It is often simpler to work the tenons with the rebate plane rather than the saw. In all cases it is advisable to plough a groove in line with the joint on the mortised piece. This necessitates a continuous haunch running right across the tenons to fill in the groove.
- Twin tenons. When jointing heavy material such as table legs, the two-tenon joint is useful. Where practicable the tenon can be taken right through and wedged. Both tenons and mortises should be marked with the mortise gauge from the face side.
- Drawer rail tenons. A form of double tenons used to join a drawer rail to the end.