Edge Joints At Right Angles

Edge joints not only make flat panels, they can also make sturdy long-grain right angles. In terms of glue and grain direction, it's all long grain glued to long grain.

The long-grain right angle can be extremely useful in designing and constructing furniture. Used alone, it can make the leg of a table or the corner of a cabinet; used in pairs, it makes a square column. (See drawing, below.)

Glue alone is enough to join the long-grain right angle, provided you square and smooth the parts with the same care you would give to a flat glue-up. Alternatively, you can make a rabbet joint, and you can create a decorative element if you saw the rabbet short, as shown in the drawing. The short rabbet shows as a reversed corner, which you can highlight with paint or fill with a decorative bead.

The rabbet aligns the joint in one direction. When you glue it up, make sure you use glue blocks sized and placed to squeeze the mating parts together.

If you want more certain alignment, you can design a rabbet-and-groove joint. The principle is the same as the tongue-and-groove, but a tongue would be centered, whereas the rabbet creates the tongue on the inside face of the wood. Make the groove the thickness of the carbide saw blade.

All of these long-grain right angles show a joint line somewhere other than at the corner. When your design demands a perfectly symmetrical appearance, a long-grain miter is the answer. It can be plain, or augmented by a spline or biscuits.

The spline should be set right at the root of the miter and it should not penetrate more than one-third the thickness of the wood. If you shift the spline up the face of the miter, or make it any deeper, you risk seriously weakening the joint. Biscuits will Ix? located by the miter fence that comes with your slot-cutting machine. But because biscuits are intermittent, they're not likely to cause problems, so long as the slots aren't so far up the miter that they break through the show side.

Good clamping is the key to designing and making the long-grain miter and any of its variations. You have to put pressure at right angles to the miter, so rip some long, 45° clamping blocks, glue them onto the face of the wood opposite the miters, and add C-clamps. After the glue sets, you can bandsaw the blocks off the wood and clean up with a smoothing plane. —I.K. and I.K.

0 0

Post a comment