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 Ian's bench will provide not only
a proper workstation, but essential feedback on the flatness of your stock as well as your planing technique.
The workbench top is to the woodworker what a face plate is to the machinist - a surface used as a reference. In wood terms, it's a dead flat, hard surface. Its edges and ends are square. It won't sag under load. About every two or three years, any distortion due to movement, wear, or dings can be skimmed back to accuracy by planing. It needn't be babied like a piece of furniture, but you don't cut into it by chiseling, sawing or drilling. Apply oil to keep it clean and protected from spills. If you must use it for glue-ups, protect it from clamp heads and glue drips with a sheet of Masonite®.
Benchtop Characteristics
Well: Many contemporary benches offer a well as "a place to put your tools." My experience is that the tool you want is in the well under the board which you just carefully clamped into place to do the work that requires the tool! My bench has no well.
Structure: In the past, benchtops were made of two or three thick slabs of readily available quarter-sawn hardwood, maple in the U.S., beech in Europe. Both are light-colored woods, which reflect light very well, and thus greatly help when setting a plane or using a try square. Making fine visual adjustments over a dark bench is like working in a badly lit room. The days of big slabs are gone, so an excellent alternative is to laminate strips of flat-sawn material.
Their combined edges then create a "quartersawn" surface. I used 8/4 flat-sawn soft maple 6" wide, sawn down the center, then planed and thick-nessed to yield as big a section as possible. I managed 1-3⁄4" x 2-3⁄4".
Making the Top
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| To begin making this elegant and eminently practical bench, start with
its top. Glue 16 laminations together to create a solid and stable
surface. |
Lay the strips out to choose the best color and grain pattern, then number them for an orderly glue-up. I used 16 strips to make a top 28" wide. Gluing this many strips together requires a flat, solid surface on which to work, such as an existing bench or sheet stock supported by battens and sawhorses. I used 11 bar clamps, augmented by upwards of a dozen fast-acting clamps to align the edges. I applied Titebond® II glue with a 3" paint roller. Pressing firmly to wet the surface, roll a light coat on each face. The squeeze-out should show as small beads, not drips. Between jobs, store the roller and tray in a plastic bag, folded over to make an airtight seal. How many strips you glue in one clamp-up depends on whether you work alone or with a helper. The real dividend of a helper is having someone at the other end of the board to lift and shift and at the other end of a clamp to attend to its positioning and other tasks. Working as two, you could begin with as many as six center strips. Working alone, begin with three center strips. Position five clamps equally spaced on the work surface. The remaining six clamps sit on top of the work, spaced between the bottom five. Using fast-acting clamps, align the surface of the laminates by keeping both heads of the clamp centered on the glue line. Also align the ends. After the first glue-up dries, add one strip to each side to allow ample time for precise alignments before the glue cures. By carefully managing the assembly this way, I needed to remove only 1/16" to flatten the top. It's possible to make three glue-ups a day: morning, noon, and evening.
Flattening the Top
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| The top is flattened by cross-grain planing. Begin with a 6" to 9" band
at one end and flatten band-by-band to the other end. The straightedge
and winding strips are essential for accuracy, and the bench brush
ensures cleanliness. |
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| Cross-grain planing produces these typical "fold-up" shavings, which
are thick in the middle and thin at the edges due to the curve in the
plane blade that prevents plane marks. Clearly evident is the glue line
that connects the two laminations. |
Make the top flat by planing across the grain. This may seem counterintuitive, but it's the best way to remove the slight but inevitable unevenness in the laminations. As well, all woods plane well across the grain with minimal tearout. It's important to follow a planing pattern. Begin at one end and concentrate on a band 6" to 9" wide. Move to the next band as flattening occurs. After flattening the final band at the other end of the top, set the blade finer and start again. Use your straightedge from the very beginning and check every direction. Use a bench brush repeatedly to avoid planing over shavings. And keep the blade sharp. As the surface becomes more refined and the depth of cut is reduced, the shavings become like duck down and the planed surface is left very smooth. Don't sand the benchtop because the residual abrasive grit will dull your blade after only a few plane strokes when the occasional re-flattening is required.
The top must be flat in length, flat in width, and out of winding. Use a two-foot straightedge to check your flattening progress at close intervals across the top. I also used a six-foot extruded aluminum level to assess the flatness of the overall length. Use winding strips end to end, middle to end, and across the top to make sure there is no twist.
The maple bench stop is a sliding fit through a hole in the top and is anchored to a leg of the underframe by a coach bolt. A wingnut on the bolt allows for easy locking of the stop at the desired height. You will need to chop the hole in the top to accommodate this feature.
The Underframe
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The rail numbers match the leg numbers. Top rails are marked on the top edge, bottom rails on the bottom edge. |
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| Locate the numbers so they are undisturbed when the joints are cut.
The numbers read clockwise and are marked on the side where the long
rails meet the legs. The arrows point to where the short rails meet the
legs. |
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| Ian removed the waste in the leg's open mortise with a coping saw. |
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| Glue the rail blocks to the long rails and clean up with a smoothing plane. |
The bench underframe must be sturdy enough to support the mass of the top and any of the work that goes on the top, and to resist racking when it has to be moved or during bench operations such as planing. Almost any softwood or hardwood will fit the bill. The one shown here is made of mahogany and put together using through-wedged mortise and tenon joints and bridle joints. It calls for legs over 3" square with rails almost 2" thick.
The end frames are sized sufficiently inboard from the edges of the top so that fast-acting clamps can be used all around it. The deliberate absence of a long top rail allows long clamps to pass unimpeded under the top to hold assembled furniture parts firmly to the edge of the bench to be further worked on. The top itself provides the anti-racking benefits of a top rail when it's attached to the underframe.
Attaching the Top to the Underframe
For many years I insisted that the top and the vise be attached by machine bolt and nut. It meant lots of work boring accurate holes and fitting 10 neat plugs to cover the bolt heads. Then, many benches ago, I began using lag screws, and my confidence in their lifelong holding power remains firm. The top has six lag screws, one in the center of the end top rail and one as far to each edge of the end top rail as is practical. I used 3/8" diameter lags that extend to within 1/2" of the benchtop surface. The center lags have a 3/8" clearance hole and the four outer ones have a 5/8" clearance hole to allow the top to move unhindered through its shrink and expand cycles.
Mortise and Tenon Underframe
This underframe uses through mortise and tenon joinery - a typical furniture maker's joint - but on a big enough scale to qualify as post-and-beam construction. Because of its large size, the joint is cut with a mixture of hand and machine tools rather than hand tools alone. There are many ways to achieve the end result and each depends on the machines you have available. For example, provided you get the geometry of the joint correct, you may cut the tenons on a band saw, whereas I used a table saw.
Making the Underframe
Start off by marking out each joint as though it were to be made by hand. I had to dodge some growth defects in the mahogany stock, so the first thing to do once the parts are milled is to decide on the layout (which parts go where) and mark each part clearly. I used numbers and arrows made large with a felt pen. The numbers and arrows tell you the inside faces, which is important to know when you cut the slopes on the ends of the mortises to accommodate the wedges. None of the marks are planed or sanded off after assembly, but they will be hidden. They were also recorded on paper as a backup.
Mark out the joints with marking knife, try square and mortise gauge. The top joint doesn't have a unique name. It's a variation on a bridle joint which in the U.S. is often called an "open mortise and tenon." The top edge of the rail sits proud of the top end of the leg by 1/4" to avoid the following problem. If the leg and rail are made flush and shrinkage in the rail occurs after the top rail is attached, the ends of the legs would be proud of the rail. The shrunken rail would then pull the top into a cupped or curved state. The bottom edge of the joint has a 1/4" cosmetic shoulder. I coined the word "cosmetic" because its main purpose is to hide shrinkage and to cover any less-than-perfect edge you may have made on the bridle opening. Both parts of the joint can be cut on the table saw.
Cutting the Leg and Rail Joints
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| Clamp a rail square and upright in your tenoning jig. The jig guides the cut and keeps your hands safe during the operation. |
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| A block clamped in place on the front of the jig positions the rail to cut the cosmetic shoulder and avoids sawing into the jig. |
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| Slower is surer: knife the shoulder lines and clean up with a wide and sharp chisel. |
Cut the leg mortises first in the tenoning jig shown in the photos.
In each case, the rectangular peg and the rectangular hole are centered, so after you cut one side, turn the part around and cut the other side. This procedure can only produce cuts that are correct and alike if the parts have exactly the same thickness. That's why careful preparation of your stock is so important. Clean up the bottom of the joint with a chisel. Cut from each side shoulder line to leave a mound in the middle. Once you have established both shoulder lines, remove the mound by horizontal paring. The jig is guided by the fence and advanced by your hands, safely distant from the saw blade. The fence controls the setting. To effect a slight adjustment when setting up the cut, slacken the fence locking handle, then lightly tap the fence with a hammer. Because the saw is set at full height, it would cut deeply into the jig, so I glued on the thick bridge pieces front and back to stiffen its structure. Because the rail thickness differs from the leg thickness, you must change the settings. However, the tenon is centered on the rail, so this setting stays unchanged. Turn the workpiece around to make the second cut. The tenon should fit tight. Offer the uncut rail to the completed leg part of the joint and assess how close you need to be to the mortise gauge line. Set the blade only 1/2" high. Set the work in the tenoning jig so that the cut will err on the rich side. Saw both faces. Because the rail thickness differs from the leg thickness, you must change the settings. However, the tenon is centered on the rail, so this setting stays unchanged. Turn the workpiece around to make the second cut. The tenon should fit tight. Offer the uncut rail to the completed leg part of the joint and assess how close you need to be to the mortise gauge line. Set the blade only 1/2" high. Set the work in the tenoning jig so that the cut will err on the rich side. Saw both faces.
Clamp the work in the miter gauge and set the blade to the correct height to remove the newly cut face. Now test the 1/2" stub tenon against the mortise. If the tenon is too rich, release the fence lock handle halfway, adjust the fence with hammer taps, and re-test.
Because the rail is too wide to fit inside the tenoning jig, it's mounted instead on the outside at the front. Although you can cut shoulder lines directly from the saw, getting consistent results on every piece is risky business. I take the slower but surer route: knife shoulder lines, saw within a 1/16", and clean up with a wide chisel.
Making the Mortise and Tenon Joints
The normal order of cutting a mortise and tenon by hand or machine is to cut the mortise first because it's easier to adjust the tenon thickness to match the mortise width than vice versa.
Cutting the tenons on the bottom end rail employs the same jig and technique as cutting the tenon on the bridle joint, with the difference that there is a cosmetic shoulder on all edges and saw kerfs for the wedges.
Making the Mortises
Only the final walls of the mortise are cut with a router. Why? To avoid the excess dust that routers create. The answer is to remove as much waste as possible by drilling. Your first bit choice would likely be a Forstner.
However, not being good at removing its own waste, Forstners tend to choke and burn. I recommend a spade bit. It makes a very clean hole, even in very hard wood - but it does have its foibles. The trouble comes when you stop drilling to withdraw the bit. Being rarely concentric, the emerging bit can quickly make
a mess of a clean hole, along with an alarming amount of vibration and noise. The solution is to clamp the work for each new hole, drill deep enough until the point just breaks through the bottom face, switch off the machine with the bit at the bottom of the hole, and then withdraw the bit when it stops. Result: a perfect hole. By clamping the workpiece, the hand that would normally hold it is free to safely hit the off switch while the hand on the drill press handle holds the bit at full depth.
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| Use a 7/8" spade bit on center to leave 1/16" of waste on each mortise wall. |
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| Clean up the mortise with jig-guided router bits. The insert (right) lets you cut two sizes with the same jig. |
The next step is to remove the fluted walls. Use a 1-inch chisel, being careful not to cut beyond the outer edges of the holes.
The remaining waste is removed by two router bits, a pattern bit (guide wheel on the shank) and a trim bit (guide wheel on the tip). The jig is an exact rectangle cut into 1/4" MDF. Clamp the jig in place and clean up the sides of the mortise with the 1" long pattern bit. Turn the leg over, clamp the jig from the same face, and rout again. Remove the jig, set the trim bit to depth, and clean out the waste remaining in the center.
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| Put the leg in the vise on a support block and chop out the bulk of the
waste using a mortise chisel. |
Then complete the cut by pressing a sharp bench chisel tight against the face of the
angled guide block. |
Cutting the Ends of the Mortises
Knife the lines for the wedge openings on the outer faces of the legs. I decided to wedge out the longer rail joint 5/16" and the end rail joint 1/4". By drawing both joints full-size you can determine the gradient and make guide blocks (see photos at right) to direct the chisels in cutting the slopes. Whenever paring or chopping a workpiece held in a vise, rest it on support blocks that sit on the vise guide bars. This frees you from tightening the vise to resist downward pressure from paring cuts and mallet blows, and the work is easily returned to level and height after checking.
Making the Tenons
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| A successful mortise and tenon glue-up requires thorough wetting of all
surfaces. I use a small paint roller for the tenon and a paddle for the
mortise. Dry clamp every assembly (left) to confirm joint accuracy and
the presence of all necessary clamps and protection blocks. |
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Dry Clamping: Always Essential
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The bottom rail tenons are made in the same way as the "open tenons." Begin by offering the tenon piece to the newly cut mortise and decide how close you should cut to the mortise gauge line. Make a 1/2" or so depth of cut, saw some temporary shoulders, and test this stub tenon in the mortise. Adjust the cut as necessary and cut the finish tenons: faces, shoulders, and cosmetic shoulders. Next, saw the kerfs for the wedges. Use a 3/32" blade set 1/4" from the edge and ending 1/4" short of the shoulder line. (The wedge kerfs are made using the same jig setup that was used for the cosmetic shoulders.) The long rail tenon is too heavy and too tall to stand upright in the tenoning jig. Use a 3/4" dado head and make multiple passes across each face. Clamp the work to your miter fence and make a trial cut from both sides about 5/8" from the end. Check this stub tenon in a mortise, adjust the blade height as necessary, and complete the cut. The cosmetic shoulders and the wedge kerfs are made by sawing down the tenon as in ripping, then cleaning up the curved-out bottom with a back saw or narrow chisel.
Final Details
Sawing the Leg Ends: Form a standing pad so that the the leg ends won't break out at the edges when the bench is dragged.
Holes for the Lag Screws: I used 4-1⁄2" lag screws to hold the top to the underframe. Drill 1-1⁄8" counterbore holes in the top end rail for the heads. The two center clearance holes are 3/8" and the four outside clearances holes are 5/8" to allow the top to shrink and expand.
Assembling the End Frames
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Close the shoulders using two bar clamps. Check that the top ends of the legs are as far apart as
the distance between shoulders. Drive the two wedges, alternating the
hammer blows. The hammer will bounce and the note changes when the
wedge is firmly home. When the glue has cured, sawoff the excess wedge and then clean the joint up with a plane.
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Once the end frame parts are made and ready to assemble, finish the rails and the inside faces of the legs. I used an oil finish. Finishing at this early stage allows glue squeeze-out to dry on the shoulder line. Clear it away with a sharp chisel and the result is a clean, clear surface and joint line. Begin by clamping the end frame dry. This obliges you to get all the necessary clamps and protection blocks in place. No matter how long-winded the dry clamp-up seems, it's a vital step toward a successful glue-up. Put the parts together dry and check for square, twist and alignment. Then glue, clamp and drive in the wedges. Now that the end frames are complete, use the same steps to complete the underframe.
You'll need to mount the vise to the top, as described below, before your work is done. Attach the bench stop to its leg and engage it as you mount the top to the underframe.
Clean up and oil all of the unfinished areas, and you are ready to put this new and essential tool to work in your shop.
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