Page 4, Secretary Desk Go back to Page 3. Go back to Page 2. Go back to Page 1.

Join the four top and bottom rails to the sides with dowels, or with biscuits. In the case of the former, accurate drill press setups will be necessary to bore the holes in the desk sides, and a dowel jig will suffice for the rail ends. For biscuits, the lower rails can be joined with a single setup of the biscuit joiner fence as in photo 10. Locate the biscuit at about 1/8" from the inside of the bottom rails. This is because on the back bottom rail you will cut a 1/4" rabbet on the outside of the rail to take the plywood back, and the biscuit must be out of the way of this rabbet. On the front there won't be a dado, but use the same setup as on the back to save some time.

Photo 10- Use a biscuit joiner to locate biscuit splines for the top and bottom rails. Or, use a dowel jig for dowel holes in the rail end, and set up with a drill press to bore dowel holes in the desk sides. If you don't have a drill press, make a wood drilling guide by boring a hole of the dowel size you will use in a thick chunk of scrap. Align this chunk on the desk side so that when the drill bit is placed in it, the bit will be aligned correctly for the dowel. Use this to bore the dowel holes.

The top rails are positioned horizontally along their faces, unlike the bottom rails, and so require an extra step with the biscuit joiner. You can't cut the slots for the top rails in the desk sides by resting the machine's fence on the desk side's edge, as you did for the bottom rails. You must position a fence along the desk side as in photo 11, and butt the bottom of the machine against this fence. This requires careful measurement to locate the slot accurately, because you must account for the distance from the cutter to the outside face of the machine, which butts against the fence. On mine this measure was 13/32", which required some mathematical gymnastics to figure exactly where to locate the fence. Measure twice, cut once.

Photo 11- Aligning the biscuit joiner to a desk side for the top rail joint. You need to know exactly how far from the biscuit joiner base the blade is located in order to accurately locate the clamped on fence.

Locate the rear top rail 1/4" forward of the desk side rear edges, because it must be out of the way of the plywood back.

Cut rabbets in the rear edges of the desk sides for the plywood back, as well as in the top outside edge of the rear lower rail. Cut these on the table saw with a dado, or with a router and a 1/2" rabbeting bit. Don't cut the rabbet all the way through on the bottoms of the sides. Stop it where the rabbet on the rear lower rail begins. To do so on the table saw, you must start the cut in the middle of the panel for one side, and stop the cut in the middle for the other. For the latter, turn off the saw when the cut reaches the end point, and wait for it to stop before removing the panel. Don't try to "climb the cut" on a table saw, that is move the work onto the blade in the direction it is spinning. This is tempting for stopped cuts but extremely unsafe with a table saw.

Cut out the desk top to fit in its dado, and prepare to assemble the carcase. The only parts that get glue are the biscuit joints that join the rails to the sides, and if you wish, the desk top to the sides. But you cannot glue the drawer frames onto the sides, because their grain direction runs at 90o to the grain direction of the sides. Cross-grain gluing like this over a wide expanse of panel will cause failure because the panel will expand and contract along its width with moisture variations, and the drawer runners will not expand and contract along their length. Truth is that the runners will do so along their length a tiny bit, but so little you can't measure it. But the side panels will move 1/8" or more, and if they are glued to the rails something must break. You can glue the desk top to the sides, however, because its grain direction runs the same as the sides, so it will expand and contract with the sides and thus stay aligned.

So how do you join the runners to the sides so that the panel can move? Use screws with holes that are larger than the screw shanks, so that as the panel moves it does not bear against the shank directly. Glue the rails and desk top pieces, and assemble the carcase with the drawer frames placed within their dadoes. Scribe light lines across the sides where screws will hit the centerlines of the drawer runners. Use a tapered bit and countersink setup to drill holes for four screws in each runner. Set the countersink just deep enough to glue in a plug over the screw once it is set. Use a drill bit of a size for a good fit on the screws. Then- before you set the screws- use a larger bit to expand the diameter of the hole in the desk side by half the difference between the screw shank and the screw head. Don't make the hole too large, or the screw head won't have anything to grab. Then set the screws, and glue plugs in place.

As I said above you can glue the top in, but end grain gluing like this is not always the best. Since you are there with screws anyway, you might as well screw it down too. The hole depth you use in the runners may not be best for the holes in the top, since you are going into endgrain. A slightly less deep, or less wide, hole may prove better for a good grip. In general longer screws work better in end grain. Do tests in samples of the same wood.

There is one other accomodation you must make for the movement of the sides- the length of the runners. Be sure the total length, front to rear, of the drawer frames is slightly (1/16" or so) smaller than the space in which the frames fit. This is so that if the sides shrink they will not compress the plywood back of the cabinet against the ends of the drawer frames, in which case the frame would actually push the plywood out of its rabbet.

After the carcase is out of clamps, apply kickers under the desk top for the upper drawer. Use screws with larger shank holes in the kicker, just as you did for the drawer runners.

DRAWERS AND CUBBIES

The advantage of dovetails is that the parts are mechanically locked together. You can acheive the same effect with router-cut sliding dovetails, and they take less time. This project uses sliding dovetails to join the drawers together as well as to join the cubby parts to each other and to the top plate.