Cutting Mortise and Tenon Joints

Mortise and Tenon Joinery

The key to building this bookcase is mortise and tenon joinery. All the cuts are square, so great results are just a matter of taking your time and laying out the joints with care.

Start by preparing stock for the stiles (pieces 1), according to the dimensions in the Material List, next page. Use the Elevation Drawings to lay out pairs of upper and lower through mortises in the stiles. These mortises will house tenons cut on the ends of the rails (pieces 2 and 3). If you're using quartersawn stock for the stiles, notice that the flake pattern only appears on two faces of the stile blanks. The other two faces are plain sawn. Keep the sides with the attractive flake patterns facing-forward so they'll show prominently.

If you have access to a mortising attachment for your drill press, cutting true, square mortises is easy work. However, most of us drill out the waste on a drill press, then clean up with a sharp chisel (as shown in the sidebar at right). Whichever method you use, make a few test mortises first. Grain direction is a significant issue with wide grained species such as white oak: a sharp cut along the grain can cause splitting, so work across the grain whenever possible. One last tip on this procedure: be sure the surface you are drilling into is without voids to steer clear of unsightly tearout.

Once the eight through mortises are cut and cleaned up, mill a groove along the inside edge of each stile.

You can cut the tenon cheeks in the rails with a standard saw blade by standing the rails on end and against a tall auxiliary fence mounted to the rip fence. Or mount the rails in a tenoning jig for even more stability.

Scribe a line around the mortise with a sharp chisel or knife before you drill out the mortise waste. Scoring the wood fibers first will help minimize splintering. Once the primary waste is drilled out, smooth and square up the mortise with sharp chisels.

Arts And Crafts Mortise And Tenon Mirror

The usual convention for cutting mortise and tenon joinery, like the through mortise and tenon joints in this project, is to mill the mortises first, then cut the tenons to fit. The reasoning here is simple: your drill bit or mortising chisel automatically establishes the width of the mortise. It's easier to trim the tenons to fit the mortises than it is to tweak the width of the mortises.

If you bore your mortises as shown here with a drill press and Forstner bit. drill the ends of the mortise first, then make a series of side-by-side holes along the length of the mortise. Once these are cut, go back along the mortise and drill out the crescent-shaped waste areas that remain. Then shave the walls and ends of the mortise smooth and flat with sharp chisels. When the mortise extends all the way through the joint, as it does for the bookcase stiles, use a backup board beneath the workpiece to keep the drill bit from tearing out the bottom surface as it exits the wood.

Table saws make quick work of cutting tenons. If you cut the wide tenon cheeks with the workpiece on end, as shown here, secure the wood in a tenoning jig or support it against a tall auxiliary fence mounted to the rip fence. It shouldn't rock or tip away from the fence as it passes through the blade, or a kickback could occur. Cut the short tenon cheeks with the workpiece held on edge against the saw table and backed up by the miter gauge.

Scribe a line around the mortise with a sharp chisel or knife before you drill out the mortise waste. Scoring the wood fibers first will help minimize splintering. Once the primary waste is drilled out, smooth and square up the mortise with sharp chisels.

You can cut the tenon cheeks in the rails with a standard saw blade by standing the rails on end and against a tall auxiliary fence mounted to the rip fence. Or mount the rails in a tenoning jig for even more stability.

Htt4 Simpson Hold DownMortise And Groove

Figure 1: Plow grooves into the rails on your router table with a 3/4" straight bit. Clamp stops to the fence to control the length of the groove.

Figure 2: Drill pilot holes to hold the screws that will secure the fixed shelves. Reshape the tops of the holes with a 3/8" chisel to accept square plugs.

Figure 3: Use a depth gauge on your drill bit and a template to place the holes for your shelf supports. A piece of pegboard works great for drilling these rows of holes.

Figure 1: Plow grooves into the rails on your router table with a 3/4" straight bit. Clamp stops to the fence to control the length of the groove.

Figure 2: Drill pilot holes to hold the screws that will secure the fixed shelves. Reshape the tops of the holes with a 3/8" chisel to accept square plugs.

Figure 3: Use a depth gauge on your drill bit and a template to place the holes for your shelf supports. A piece of pegboard works great for drilling these rows of holes.

Notice in the Side Panel Assembly Elevation that these grooves run from through mortise to through mortise and serve to capture the outer slats. The easiest way to mill the grooves is on the router table with a 1/2" straight bit raised to 1/4". Test your setup on scrap stock, then use pencil marks on the router table fence and stock to start and stop the cuts at the mortises.

With the grooves completed, mill a chamfer around the top edges of the stiles using a router and 1/4" chamfering bit or a block plane.

Riding the Rails

The upper and lower rails (pieces 2 and 3) join all the fixed structural elements of the bookcase. Rip and crosscut the rail stock to size, then cut three mortises into the edges of the rails to house the outer and center slats (pieces 4 and 5). Use the Side Panel Assembly Elevation to find their locations.

Next, form tenons at the ends of the rails. See the Upper Rail and Stile joinery Detail on the previous page to lay out the tenons. Use your table saw and a tenoning jig to make the tenon cheeks by slicing off each side of the rails. This will reveal a notch in the tenons because of the mortises you cut earlier. Now lower your saw blade to 1/4" and switch to the miter gauge to nibble away the edges of the rails and form the tenon shoulders. Chamfer the ends of the tenons as you did on the stiles.

Install a 3/4" straight bit into the router. Use this setup to plow grooves on the inside of each rail (see Figure 1

and the Upper Rail and Stile Joinery Detail). These grooves will accept the ends of the top and bottom shelves, so make them 3/8" deep and IOV2" long. It's OK to leave the ends of the grooves rounded, as they will be hidden by the notched corners of the top and bottom shelves. On the bottom rails, lay out the 21" radius as shown in the Elevation Drawings. Use the band saw to cut these curved arches. Sand the edges to remove the saw marks while keeping the gentie curves identical.

Cut the slats to size (pieces 4 and 5) and notch the ends, following the Slat Notch Detail Drawing. The ends of the slats remain at full thickness and will fit into the stopped mortises you cut earlier in the edges of the rails.

Test fit the side assemblies by placing the notched ends of the slats into the rail mortises, then drive the stiles onto the slat and rail subassembly. When everything fits correcdy, disassemble, apply glue and clamp the parts together. Keep the side assemblies perfectly square and flat until the glue cures and scrape off any excess glue after it has set.

The Shelves and Their Supports

There are four shelves in this bookcase: two fixed shelves and two adjustable middle shelves (pieces 6 and 7). Cut them to size, now. Note that the middle shelves are shorter than the fixed ones: this is because the latter fit into the mortises you made in the rails. The top and bottom shelves are glued in place and then secured with screws (pieces 8) whose heads will be hidden by square

Matching the traditional fumed Stickley finish with less toxic alternatives is a challenge. I found that using a gel stain followed by a complementary gel varnish does the job quite handily — and without the need for a fuming tent, chemical gloves or a respirator.

wooden plugs (pieces 9), as shown in Figure 2. Make the plugs by ripping strips from your 3/8" plug stock and crosscutting the strips Into plugs. Pre-drill pilot holes through the rails and then, with a chisel, cut 3/8" square mortises over the holes to receive the square plugs. (Note: Make these plug holes 1/4" deep.)

Notch the ends of all the shelves by gang cutting them in pairs using the table saw and your miter gauge. See the Elevation Drawings to lay out the differing dimensions and shapes of the notches — those on the top and bottom shelves are deeper than the middle shelves. After checking the fit of the top and bottom shelves in the rails, apply glue in the rail mortises and insert the shelf tenons. Secure them with the screws, then glue the plugs in place.

All that stands between you and the finishing room is to make four rows of shelf pin holes in the stiles of each side assembly for the two adjustable shelves. Refer to the Elevation Drawings again to determine the starting and stopping points of these rows. Drill the holes using a piece of pegboard as a template and with a sharp brad point bit fitted with a depth collar. Clamp the template evenly in place on each stile before boring the holes.

Give all the project surfaces a thorough sanding up to 220 grit before proceeding with finish.

Craftsman Furniture Jointery

A Safer Stickley Finish

Stickley developed a unique method of fuming white oak with ammonia to create a glowing aged and mellow color. Mimicking the unique look of the Stickley finish was a challenge I took seriously. I used Bartley's honey gel stain to approximate the same fumed effect with much less fuss and danger. It's also convenient for staining vertical surfaces without the drippy mess. Just be sure to wipe all the excess gel out of nooks and crannies. Protect the wood with a few coats of satin varnish — the gel variety goes on smoothly and won't sag if you accidentally apply too much. It produces a rich luster that is very much in keeping with the Arts & Crafts tradition. The shelf supports (pieces 10) are the brass plug-in type; install them after the finish dries.

This is such a classic bookshelf that I'll wager you're making a second or third as soon as this one finds a prominent spot in the living room or den. @

Matching the traditional fumed Stickley finish with less toxic alternatives is a challenge. I found that using a gel stain followed by a complementary gel varnish does the job quite handily — and without the need for a fuming tent, chemical gloves or a respirator.

By Rick White

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