On almost any woodworking job, you occasionally need to make a strong corner joint. But there are many types of corner joints. Which type is best for the job you are undertaking?
The simple butt joint is most commonly used (Fig. 1). This joint is formed by nailing or screwing the end of one piece of wood to the end of the other. While this is simple, fast and effective, the butt joint cannot be used on many types of end joints.
A simple butt joint leaves the heads of the screws or nails exposed. Of course, the heads can be countersunk and covered with water putty or wood filler if desired.
The dowel joint is basically the same as the butt joint except dowels are used to hold the two pieces of wood together instead of screws and nails (Fig. 2).
You can make the dowel joint by drilling holes completely through one piece of wood and into the other. Dowels are driven into these holes, completely through one piece of wood and deeply into the other. Then glue the dowels firmly into position to provide strength and prevent slippage.
Construct blind dowel joints by drilling the holes only partway into each piece of wood. Then drive the dowels into these holes and glue them into position. The dowels are not visible.
While dowel joints have the advantage of being inconspicuous, they do not provide the structural strength of a simple butt joint.
The end lap joint is made by sawing halfway through each piece of wood and then knocking out or sawing away half of this area (Fig. 3).
Now you can put the two pieces of wood together with screws, nails, corrugated nails, etc.
The end lap joint provides a great deal of strength, but the heads of the nails, screws or corrugated nails are exposed.
The through mortise and tenon joint is easy to make with a power saw and a dado head (Fig. 4). A through mortise and tenon joint is suitable for various woodworking jobs.
To form this joint, saw a slot into one piece of wood. The end of the other piece of wood is then notched out to fit the slot in the first piece (Fig. 4).
Insert the notched piece of wood into the slotted piece of wood and glue, nail or screw the piece into position.
When making a through mortise and tenon joint, be sure to measure the areas to be notched and slotted before making any cuts.
You can make an open mortise and tenon joint by cutting the slot or mortise only partway into one piece of wood. Then create a notched-out area on the other piece that fits into the slotted area in the first piece of wood (Fig. 5).