DOVETAIL JOINTS

(Combining enduring strength with an attractive apperance, the through dovetail is often used in fine furniture to join car­case corners. The half-blind version of the joint shown starting on page 108 is a good choice for assembling drawers because the drawer front conceals the end grain of the sides. Traditionally, the joint was cut using a handsaw and chisel, but many woodworkers now make it with a router. There are a raft of jigs on the market that, paired with a router, enable you to cut a variety of dovetail joints (page 88). But you can also make them by using the techniques shown in this section, producing both through and half-blind dovetails.

CUTTING THROUGH DOVETAILS ON A ROUTER TABLE

Marking the tails with a shop-made template

A dovetail joint consists of a tail board and a pin board with half-pins at each end (inset). To rout the joint, start by using a cutting gauge adjusted to the stock thickness to scribe a shoul­der line across one end of the tail board. To mark the tails, use a shop-made template; cut a piece of clear acrylic plastic about 3 inches wide and 8 inches long, then rout a notch into one end with the same dovetail bit you will use to cut the joint. The size and shape of the notch will correspond to the waste sections between the tails—that is, the pins. Set the tail board
on a work surface, position the template on top, and start by marking waste sections equal to one-half the notch width at each edge; be sure to align the template’s notched end with the board end and hold its edges parallel to those of the work – piece. Outline the remaining waste sections (above), marking them with an x as you go. There are no rigid guidelines for the number of tails required, but evenly spaced tails that are at least twice the size of the waste sections between them pro­duce an attractive and sturdy joint.

2 Routing away the waste from the tail board edges

Mount your router in a table with the bit used to notch the dovetail template and screw an extension board to the miter gauge. Securing the tail board on end, adjust the cutting height so the bit will cut to the shoulder line. Then align one of the waste sections at the edge of the board with the bit and clamp the work – piece to the extension. Butt a stop block against an edge of the board and secure it to the extension so you can rout the waste sections at each corner of the board using the same setup. To cut the first waste section, slide the miter gauge forward. Then turn the board around, butt it against the stop block, reclamp the workpiece to the extension and repeat the cut. Cut the waste sections at the other end of the board the same way (right).

3

Routing the remaining tails

Once the waste at all four corners of the tail board has been cleared, remove the stop block, then align one of the remaining waste sections with the bit, secure the workpiece to the miter gauge extension, and reclamp the stop block against the edge of the stock. Rout the waste section, then flip the board end-for – end to cut the corresponding section at the other end. Repeat the process to cut away the remaining waste sections (left).

4 Marking the pins

Secure the pin board end-up in a bench vise and hold the completed tail board in position across the end. Making sure the edges of the two boards are aligned and the end of the tail board is flush with the outside face of the pin board, run a pencil along each edge of the tails to outline the pins on the end of the pin board (left). Extend all the pin marks down both faces of the board, using a combination square to ensure that the lines are perpendicular to the end of the board. Mark each waste section with an X.

Adjusting the router table miter gauge

Since the pins are wider on the inside face of the board, you need to angle the miter gauge on your router table when you cut them (steps 6 and 7). To determine the correct angle, use a sliding bevel. Holding the handle of the device flush against the end of the tail board, adjust the blade to align with the edge of

one of the tails (above, left). Then loosen the adjustment handle on the router table miter gauge, butt the handle of the sliding bevel against the gauge extension, and swivel the head of the gauge until the blade of the sliding bevel is parallel to the miter bar (above, right). Tighten the adjustment handle.

6

Routing the right-hand edge of the pins

Install a straight bit in the router and adjust the cutting depth to slightly more than the thickness of the tail board. Align the right-hand edge of the first marked waste section with the bit, butt a stop block against the edge of the stock and clamp it to the miter gauge extension. Holding the extension with both hands, feed the workpiece into the bit. Then turn the stock end-for-end, clamp it to the extension with its edge flush against the stop block, and repeat the cut at the oth­er end of the board. Move the stop block away from the bit by an amount equal to the cutter diameter and make another cut at each end of the board, continuing until you have cleared at least one-half the waste; do not rout away much more than half the waste, or you risk cutting into the neighboring pins. Repeat the process for each waste section (above), shifting the stop block as necessary.

7 Routing the remaining waste from the pin board

Once you have cut away half the waste from the pin board, remove the workpiece and stop block, and use the sliding bevel to angle the miter gauge in the opposite direction. Then follow the same proce­dure used in the previous step to clear the remaining stock from each waste sec­tion (right).

ROUTING HALF-BUND DOVETAILS

1

Marking the pins

Start by cutting the tails on your router table, as described on page 104; with half-blind dovetails, adjust the cutting height so the length of the tails equals two-thirds the thickness of the pin board. Before outlining the pins, set a cutting gauge to the tail length and use it to mark a line across the end of the pin board, closer to the outside than the inside face. Adjust the cutting gauge to the thickness of the tail board and scribe a shoulder line on the inside face of the pin board. Then use the tail board as a guide to outline the pins on the end of the pin board (page 106), but instead of lining up the ends of the tails with the outside face of the pin board, align them with the tail-end line. To complete the marking, use a try square and a pencil to extend the lines on the board end to the shoulder line (left). Mark the waste sections with an x as you go.

2 Routing out the waste between the pins

Secure the pin board end-up in a bench vise and use a laminate trimmer fit­ted with a straight bit and ar^ offset base to remove the waste from the workpiece. The offset base allows you to focus the down­ward pressure on the bench, which will help keep the tool from wobbling as you rout the waste. Screw a support board to a plywood shim and clamp the assembly in a vise with the workpiece. Adjust the stock up or down until the tip of the bit aligns with the shoulder line when the trimmer sits flat on the shim. Next, to keep from cutting beyond the tail-end line on the end of the pin board, align the bit with the line, butt an edge guide against the trimmer base, and secure the guide in place. Then, starting at one edge of the workpiece, rout out the waste between the pins (right), keeping the trimmer flat on the shim throughout the operation. To avoid gouging the pins, cut only to within 7i6 inch of their marked edges.

3

Final paring

Remove the remaining waste from the pin board with paring and skew chisels. Working on one waste section at a time, press the flat side of the chisel against the edges of the pins with a thumb and push the chisel toward the shoulder line, paring away the last slivers of waste (left).

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