IDraw the dovetail pin angle and use it to set the angle on a sliding T-bevel that you can use to mailt the pins on the ends of the pin boards. Make a scale drawing of a dovetail pin and use It to set a slidingT-benl for marking the layout lines for the pins. A standard angle Is 80°, which equals a 1:6 ratio of slope to pin depth.
2After edge-gluing and cutting toe workpieces to size, begin work by laying out the pins. Use the drawing labeled "Pin/tall layout" to lay out the pins on the end of the board with a penal and the adjustable square.
OPTION: Use a flanged dovetail layout jig to mark the dovetail pins. These Inexpensive tittle devices can be found in most woodworking stores and catalogs. They're easy to use and yield consistent results. The only real drawback to these jigs Is that they're not adjustable, and dovetails aren't a one-slze-flts-all joint.
3 Next, mark the pin length with a marking gauge. This line lets you know how deep to cut, so scribe It well.
4Finally, transfer the lines drawn on the end of the board to both faces of the board with a try square or combination square. These lines are your guides to make sure your cuts are straight.
5Use a tenon saw, also called a dovetail saw, to cut the shoulders of the pins. Split the lines with the saw, favoring the waste side. Cut down to the scribed lines, but do not cut below the lines or the kerf cut will show when the joint Is assembled.
Continued next page
How to make hand-cut dovetail joints (continued)
J Set re along the scribed baseline with a chisel to prevent tearout hen you remove the waste around the pins. To ensure a straight scored line, damp a block of wood next to the scribed line and use it as a chisel guide.
7Carefully drive the chisel Into the end-grain of the waste area between the pins so the waste wood will break off cleanly at the chisel cut along the baseline.
8Remove waste In half the area, then flip the board over and continue removing waste from the other side. The beveled face of the chisel should face toward the ends of the dovetails, with the flat face contacting the guide board. When all the waste is removed, clean up the cuts carefully with a smoothing file.
9 Once the pins are cut, lay out the talis by laying the pin board on the face of the tall board and marking the pin profiles. Use a sharp pencil so the marks are true. Also use a marking gauge to scribe a line on the face of the board, establishing the bottom line for the tails. Make sure the pin board and tail board are flush at the edges before making any marks.
nCiamp the board in a vise and use a dovetaii saw to make the cuts down to the scribed iine. Remove the waste from between the taiis with a sharp chisei, the same way you removed the waste from the pin boards. Make the shoulders of the taii board by sawing aiong the base line to the first taii on each end.
Draw straight cutting iines across the end of the tail board, using a combination square or try square. The cutting iines shouid aiign with the outiine marks transcribed from the pin board.
Prepare for giue-up by cutting wood cauis the width of the assembly and iinlng the cauis with masking tape. Apply glue to the pins and the Inside edges of tire tails, then assemble the joints. The joint should be tight enough that it must be tapped together with a mallet. Use a biock of wood between the mallet and the workpiece to keep from damaging the Joints or the workpiece. Offset the cauls from the dovetail joints and ciamp them (offsetting aliows the joint to ciose if it's cut slightly deep, so the ends of the pins protruding beyond the outer surfaces of the tailboard don't Interfere with the ciamp). Sand or file any long pins flush with the taii board where they can be sanded or filed down.
Cutting finger joints with a jig
Finger joints (sometimes called box joints) typically are made on a table saw with a dado-blade set and a jig—an auxiliary board screwed or clamped to the miter gauge. When joining parts of equal thickness, a finger joint is a good choice because it 's strong and effective. Like a dovetail, the finger joint is visible after it's assembled—a plus i f you like to show off your handiwor k (and what woodworker doesn't?). Unlike dovetail pins, finger joint pins are straight, so it's an easier joint to make than a dovetail, although it's not as strong.
To make accurate box joints, first rip-cut and cross-cut the parts to size. Cut some test slots in waste pieces with the dado blade set and check the fit of an actual workpiece in the slot. The workpiece should fit snugly without having to pound it in.
ALSO KNOWN AS BOX JOINTS, finger joints are a good choice for joining two workpieces that are the same thickness. The mating boards in the joint are identical, except that the notches arc offset the thickness of one notch on one of the boards. A table saw with a jig can be used for cutting finger joints. You can also use a router (you can buy specialty finger-joint shapers) or a radial arm saw with the biade spinning on a horizontal plane.
2 Reset the auxiliary fence by moving it a distance equal to the thickness qf one pin to the outside edge of the biade set Redamp or screw the fence to the miter gauge.
Ilnstaii a dado-Made set and throat plate In your table saw. Set the cutting width of the dado-set to equal the thickness of the finger pins to be cut. Raise the biade set to cut the fuii depth of the pins. Clamp an auxiliary fence board to your table saw miter gauge. The board shouid be about 6 in. wide and aft least 18 in. long. Make a pass of the auxiliary fence over the Made, then cut a strip of hardwood to use as a pin to fit in the siot, and gfue it into the fence slot.
3With the pin spacer inserted in the fence siot and the fence in position, butt the first workpiece against the strip and make the first pass. Ifou can hoid the workpiece in piace by hand or ciamp it to make the cut. After the workpiece and fence ciear the biade, shut off the saw and back the workpiece off.
5To cut the joints in the mating boards, fit the iast notch you cut in the first piece over the pin, then butt the mating piece against the first piece, creating a one-notch offset. Make the first pass on the mating piece. Now remove the first piece, butt the notch in the mating piece against the pin and make the second pass. Continue untii aii the joints are cut in one end, then fiip the board end-for-end and repeat.
4 Reposition the workpiece by piacing the siot you just cut over the pin space, then make the next cut Continue In this manner until aii the joints in that board are cut. Flip the board end-for-end and cut the fingers on the other end of the board the same way.
6When aii the joints are cut, the pieces are ready for assembly. Glue the joints and ciamp them together with wood cauis offset from the joints to aiiow the joints to ciose.
THE MORTISE-AND-TENON is one of the simplest and strongest wood Joints. It's comprised of a narrow tenon carved in the end of one mating workpiece, which fits Into a mortise hole In the other mating workpiece. The Joint can simply be glued, or you can reinforce it with doweis or wedges.
Making mortise-and-tenon joints
The mortise-and-tenon joint is one of the strongest joint types for one simple reason: the fastener (the tenon) is actually part of the workpiece. In addition to their great, strength, mortise-and-tenon joints are exceptionally versatile. Because you cut, the parts of the joint yourself you. can give them just about any size or configuration you want. You can also reinforce them in any of a number of ways (if you want to reinforce them). Throughout this book, you'll find many variations of the basic mortise-and-tenon joint,
Was this article helpful?
THIS book is one of the series of Handbooks on industrial subjects being published by the Popular Mechanics Company. Like Popular Mechanics Magazine, and like the other books in this series, it is written so you can understand it. The purpose of Popular Mechanics Handbooks is to supply a growing demand for high-class, up-to-date and accurate text-books, suitable for home study as well as for class use, on all mechanical subjects. The textand illustrations, in each instance, have been prepared expressly for this series by well known experts, and revised by the editor of Popular Mechanics.