When removing the waste from between the jj pins of half-blind dovetails, its difficult to reach 1
into the corners with ordinary paring chisels. Pur- ' 1
chase two extra '/2-inch chisels and regrind the 1 1 li^V^^M
cutting edges so each chisel has a 15-degree skew. ,, F JJ'i ^B
One chisel should skew to the right, and the other ■ ^ • ■
to the left. This will enable you to reach into the gftJH «,1 :£ ..
corners on both sides of each notch. Note: Some ^
woodworkers prefer to use a woodcarvers skew ^ SSK&jf chisel or a miniature lathe turners skew chisel for _ __>
Like half-blind dovetail joints, lock joints (or locking tongue-and-dado joints) cannot be seen from one direction, and are often used to assemble drawers. They are much easier to make than dovetails — you can cut them with a single setup on a table saw. The trade-off is that they don't withstand shear stress as well as dovetail joints — the wood in front of the dado will shear off if you pull too hard on the drawer front. However, they are still a good choice for small drawers or drawers that won't see much use.
To make a lock joint, mount a dado cutter on a table saw and adjust the depth of cut to equal the thickness of the board. Make a spacer that you can lay over the cutter to quickly reduce the depth of cut.
Using the fence to guide the stock — and without the spacer in place — cut a deep groove in the end of one adjoining board. This groove will create two long tongues. Put the spacer in place and cut the inside tongue short. Then, with the spacer still in place, cut a shallow dado near the end of the other adjoining board. The tongue should fit snugly in the dado. (See Figures 6-24 through 6-27.)
Note: As shown, this procedure will create a lock joint in two 3A-inch-thick boards. To join thinner or thicker boards, you must change the width of the dado cutter, the thickness of the spacer, and the location of the fence.
6-24 To make a lock joint in
3A-inch-thick stock, mount a dado cutter on your table saw and adjust it to make a 'A-inch-wide cut. Adjust the depth of cut to 7* inch. Position the fence precisely lA inch away from the cutter. From a l/2-inch-thick scrap of plywood or hard-board, make a spacer that will fit over the cutter and against the fence, as shown.
6-25 Without the spacer in place, cut a 74-inch-wide, 74-inch-deep groove in the end of one adjoining board. Hold the stock vertically, and use a square scrap of plywood to help guide the stock along the fence. This cut will create two Tt-inch-thick, 74-inch-long tongues on the end of the board.
6-26 Put the spacer in place, clamping it to the work surface of the table saw. Holding the stock horizontally with the end against the fence, cut the inside tenon short. Again, use a square scrap of plywood to guide the stock. After making the cut, the short tenon should be just 74 inch long.
6-27 Leave the spacer in place and cut a 74-inch-wide, 74-inch-deep dado in the other adjoining board. As you make the cut, hold the board horizontally with the end against the fence. Again, use the scrap of plywood to guide the stock. When the parts are assembled, the short tongue will fit the dado.
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