Sliding Dovetail Joint

rits a hybrid of the dado and the dovetail.

In the sliding dovetail joint, one of the mating pieces has a groove plowed in it, the other has a tongue formed on it; the tongue fits in the groove. Because both the groove walls and the tongue sides are angled like dovetail slots or tails, the joint has to be assembled by sliding the tongue into the groove.

The advantage of the joint is its mechanical strength. Ever, without glue, the mating pieces will stay linked together. Only if the wocd breaks will the two pieces separate. One wonderful consequence of this is simplified assembly routines. The parts won't fall away from one another while you're fumbling with clamps or fasteners. Slightly bowed panels will be pulled into line without elaborate clamping configurations. A mere two hands will usually be sufficient.

Another advantage is that the joint allows the pans to move without coming apart. A good example of this is a tabletop's breadboard end. Here you apply a narrow strip of wood across the end of a glued-up panel to conceal its end-grain and to keep it straight. The joint allows the tabletop to expand and shrink across its width even though the end strip isn't elongating and shrinking.

This characteristic of the joint, taken a little further, makes it an excellent one for moving joints. It's used for all sorts of sliding connections—drawer slides, table extension slides, and the like. We've used it in a number of our router jigs.

A variant of the joint is the woodworking equivalent of speaking softly while brandishing a big stick. The tapered sliding dovetail—if cut with precision—allows especially easy assembly, but closes extremely tight. The narrow end of the tail enters the wide end of the groove and slides effortlessly through the groove. But as the groove closes down on the tail, the joint gets tighter, and you

Routing a sliding dovetail slot is as straightforward as routing a dado. The same guides used in dadoing— here, a T-square—can be used to guide dovetail slotting.

often have to whack the work smartly to force everything into line and seat the joint. Cutting the tapered sliding dovetail requires finesse, but final assembly calls for brute force.

CUTTING THE JOINT

How you cut the sliding dovetail depends on the router setups at your disposal, as well as the location of the cuts. For example, the tails are almost always easiest to cut on a horizontal router table, most difficult with a hand-held router. Slots in casework usually are best done with a hand-held router, while those in a workpiece edge are easiest to cut on a router table.

The joint's disadvantage is that fitting the two pieces is a trial-and-error process that can get tedious. And the working stock can snooker you in the bargain.

Ideally, the sliding dovetail is a precision-fitted joint. You want the fit tight, but not so tight that friction stalls the tail as it slides into the slot. On the other hand, you don't want the fit to be too sloppy, however easy that makes the joint to assemble. The usual fitting technique is to plow the slot, then creep up on a tail dimension that fits that slot.

There's a danger in that. Because of the dovetail shape, a mismatch of the tail and slot anywhere along their lengths can prevent assembly. This is where variances in stock thickness and flatness can give you a migraine. A tail that has a thick spot, stemming from a bow in the stock or a subtle taper in its thickness, is a tail that may bind in the slot. Of

Routing a sliding dovetail slot is as straightforward as routing a dado. The same guides used in dadoing— here, a T-square—can be used to guide dovetail slotting.

coursc, it'll seize about halfway in, just after you've applied a little glue to the extremities of tail and slot. And as the wavy lines course before your eyes, signaling the onset of that migraine, the pans wedge so firmly that you can't whack them completely together or apan. Then your head really hurts.

To get the groove as right as possible, Fred suggests making two passes through it, making a special effort to keep the work (or the router)

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Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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