American Woodworker

Important Information >>

Receive New Posts

Shaker Trestle Table

RATE THIS:

Shaker Trestle Table

Graceful bent-laminated feet are super-strong.

By Chris Cander


This modern interpretation of a Shaker communal table appeals to furniture maker Mark Love’s customers because of its elegant simplicity, ample legroom, and the fact that it’s easy to clean under. But Mark loves to build it because of the feet.

“Making these feet out of glued laminations and seeing how beautiful and strong they are when you do it right is thrilling,” Mark says. “Sam Maloof made the rockers for his famous chairs using the same technique. Because the line of the grain follows the arc, they are exceptionally strong.” Building this table is an ideal way to develop your bent-lamination skills. It would be much easier to saw the feet out of 7" wide boards, but then the grain would run across the arc instead of with it. This short-grain orientation would make the feet much weaker, and more likely to break under the table's weight.

 

Materials

Mark built the 28" x 56" table shown here out of a single board of bubinga, an exotic hardwood with a ribbony texture and reddish-purple overtones. Bubinga is usually very stable and straight. “It’s not essential to make the table from a single board, but I found one that was big enough for my entire cut list,” Mark says. “It was a fun challenge to figure out how to do it, and I ended up with very little waste.”

 

Rough out the parts

1. Roughsawn boards typically have end checks (cracks in the ends) that must be cut off. To make sure the checks are completely removed without wasting precious length, nibble each end in 1/16" increments. Make a crosscut and test the thin offcut—if it breaks when you gently bend it, make another crosscut. Repeat until you get an offcut that won’t easily break. You can often lose several inches on a piece of hardwood by doing this, but it’s a small price to pay when the alternative is discovering cracks in the completed project.

2. Lay out the parts on your boards before you start cutting. You may have to try several times in order to find the right combination of efficient use and good-looking pieces.

3. Mill everything to within 1/4" of its finished dimension (Fig. A and Cutting List, below). Milling often releases internal stresses in rough boards, so once you cut the parts, sticker them and allow them to rest (ideally overnight) until the parts adjust to their new width and thickness.

 

Laminate the feet

4. Each foot consists of seventeen 5/32" thick laminations. To make the blank from which the laminations come, mill a piece that’s 2" thick and 36" long, with enough width to yield about forty 3/16" thick laminations. You can use multiple blanks if you don’t have one wide enough to get all the laminations, as long as the color and grain are consistent. Joint one edge of the blank. Then using the bandsaw, rip a 3/16" thick lamination and set it aside (Photo 1). The bandsaw leaves a rough edge, so you’ll have to joint the blank after ripping each lamination. Repeat the process until you end up with 34 laminations (plus extras, for insurance) that are jointed on one side and bandsawn on the other.

5. Run the laminations through the planer, jointed side down, until they are all precisely 5/32" thick.

6. Glue together three pieces of 3/4" MDF to make the bending form for the feet (Part A, Fig. A and Fig. B). Cut concentric arcs into the form by setting the router up twice, but keeping the same pivot point on the trammel. Using a 1/2" straight bit, make several passes until you have gone as deep as you safely can. (Photo 2). Take the form to the bandsaw and cut along the channels you’ve just made. Flip over the two jig parts, so the rough edge left by the bandsaw is at the top. Then remove the rough edges by routing with a flush-trim bit. Rub paraffin wax on both of the completed form's arcs to keep the laminations from sticking during glue-up.

7. Clamp 17 of the laminations in the form without glue and replace any that crack (Photo 3). Prepare to work quickly when you’re ready to glue— yellow wood glue has only about five minutes of open time. Apply glue to one side of all 17 laminations and stack them, maintaining the original order to preserve consistency of the grain. Do not put glue on the outside faces of the top and bottom laminations! Place the stack in the form and clamp it together. This assembly is under considerable stress, so wait 24 hours before you remove the clamps.

8. The sides of the feet are rough when they come out of the bending form. Scrape off the squeezed-out glue and joint one side to flatten it. Then run each foot through the planer, to flatten the other side. Mill the feet to final 1- 3/4" thickness.

9. Use a shopmade “lazy Susan” jig to true the curved top edge of each foot (Photo 4). Fasten the foot to the jig’s 14" radius circular piece with screws near the ends, so that it barely protrudes (about 1/32") beyond the edge. The ends of the foot will be cut off, so the screw holes won’t matter. Clamp the jig’s bottom (square) piece to the sander's table so that the foot almost touches the belt. Then gently tap it forward with a hammer until it just touches. Rotate the foot back and forth until your edge is smooth.

10. Cut each foot to its final 24" length. Lay each foot on its side and square a straightedge across the ends, 7" down from the top, at the center. Draw a line across both ends. At this line, the foot should measure 24" from tip to tip. Bandsaw each end below the line. Then sand to it (Photo 5).

 

Rout mortises

11. Two through mortises must be routed in each foot (Fig. C). The surfaces are curved, so a pair of jigs are required to complete the job. The first jig guides the router on the top of the foot (Fig. D). The holes in the jig are larger than the mortises by 1/4" all around, which allows using a 3/4" guide bushing and a 1/2" mortising bit to rout the mortises. Find the centerline of each foot (Photo 6). This line will be your reference for positioning the foot in the mortising jig. Centerlines marked on both sides of the jig match up with the lines marking the center point of the foot. Clamp the jig to the foot, using small clamps that run underneath the foot. Clamp the assembly in your bench vise and then plunge-rout the mortises halfway through the foot (Photo 7).

12. Finish the mortises from the bottom of the foot. First, drill pilot holes (Photo 8). Then use an improvised platform to hold the router level and a flush-trim bit to finish the mortises (Photo 9).

13. Rout the bottom edge of the foot, to lighten its appearance. Simply use the top half of the bending form to rout a 14" radius. Install a stop block to secure the foot and rout the arc with a flush-trim bit (Photo 10).

 

Finish-sand before assembly

14. At this point, finish-sand both feet. “Nothing affects the final finish as much as sanding does,” according to Mark.

 

Make the top rails

15. Mill the top rails (B) to their final dimensions, and mark their through mortises (Fig. E). There’s no need for a jig to rout these mortises, because the router will ride nicely on the flat surface. Install a 1/2" upcut spiral bit and set the router’s edge guide exactly 7/16" from the outside of the bit. Then plunge-rout each mortise from both sides. This creates a perfectly centered 7/8" wide mortise, although a bit of chisel work is required to flatten the peaks left where the two cuts meet. Use the drill press to drill the counterbored holes, through which the bolts that secure the top will go. Drill 1" deep with a 1" Forstner or spade bit, and then switch to a 3/8" brad point bit to drill the shank holes.

 

Cut the tenons

16. The uprights (C) feature wedged tenons on both ends (Fig. F). Note that the bottom tenons are longer. Start by cutting the tenon shoulders on the table saw, using the miter gauge equipped with a fence and a stop block. Saw the tenon cheeks slightly oversize on the bandsaw. Then install a dado set to precisely cut the tenon cheeks to final thickness.

17. Radius the tenon edges to fit the mortises with a 1/4" roundover bit, followed by paring or sanding (Photo 11).

18. Assemble each end to make sure everything fits. Disassemble the parts and then use the bandsaw to cut slots in each tenon for the wedges.

19. Shape the bottom shoulders of the uprights, so they fit properly on top of the arched foot. Make a jig to hold each pair of uprights for routing (Fig. G). The jig has a 14" radius arc to match the foot and a center divider that exactly positions the uprights. Place an upright on each side of the divider with its top shoulder registered against the 1/4" spacer. Clamp the uprights together across the jig. Flip the assembly over and mount it in your bench vise. Then use a flushtrim bit with a top-mounted bearing to rout the uprights' arched shoulders (Photo 12). Flip the uprights over, reinstall them in the jig, and repeat the process to rout the remaining shoulders. After routing, you'll have to finish the job by hand (Photo 13).

20. Fit the tenons in the mortises and check the shoulders. The bottom tenons will protrude. Cut off the extra length, leaving just a bit to be cleaned up later with a flush-trim bit.

 

Assemble the base

21. Mill the stringer (D). Then locate the dadoes for the uprights (they’re spaced 28-3/4"). Size the dado widths so that the unsanded uprights will almost, but not quite, fit. When the uprights are finish-sanded, they’ll fit perfectly.

22. Draw the arc on each end of the stringer and then sand to the pencil line (Photo 14).

23. After finish-sanding all the parts, it’s time to assemble the base. There’s no joinery to hold the uprights to the stringer, so carefully measure and mark the centerpoints on both the uprights and the stringer, and match them up. Brush glue into the dadoes, install the uprights, and gently apply clamps. Then knock on the top rails to keep everything in place (Photo 15). Allow at least a couple of hours for this assembly to dry.

24. Remove the top rails, apply glue around all the tenons and slide them back on. Repeat with the feet (Photo 16). Draw the parts together with clamps, using small wooden blocks to protect the already finishsanded pieces.

25. Complete the base by driving in the wedges that spread and lock the tenons (Photo 17).

 

Glue up the top

26. Lay out the rough-cut boards you’ve set aside for the top (E) to create a pleasing appearance. Once you’re satisfied with your layout, draw a chalk triangle on the boards to make it easier to maintain the order as you joint the all the edges. Alternatively mark the edges “I” and “O” to designate which side goes “in” or “out” against the jointer fence. This cancels out unsatisfactory results caused by a slightly outof- square jointer fence. Check the fit of each joint as you joint the edges.

27. Although they aren't absolutely necessary, you may want to use biscuits or splines to align the boards for gluing. Mark swears by Domino tenons, spaced at 10" to 12" intervals. Spread glue on the edges of each board and then glue and clamp the top (Photo 18).

28. Use a shop-made trammel to rout the 66" radius arcs on the ends of the top (Photo 19). Then finish sand.

 

Apply finish and attach the top

29. Apply your favorite finish to the top and the base. Mark uses a HVLP gun to spray lacquer in satin finish. Let each coat dry, sand with 400 grit paper, and then spray another coat.

30. Now the base is sanded, finished and ready to go. Place the top upside down on a blanket to protect the finish. Then measure and set the base onto the top where it will go. Poke a 3/8" brad point drill bit through the holes in the top rails and tap it with a hammer to mark the top.

31. Drill 9/16" deep holes in the top and use a T-wrench to drive in the 1/2" brass threaded inserts (see Source, below). Position the base on the top and fasten it (Photo 20). There’s enough play between the 3/8" shank holes in the top rails and the 1/4" bolts to accommodate the top’s seasonal movement.


Source

McFeely’s, mcfeelys.com, 800-443-7937, 1/4-20 Brass Threaded Insert, #3606-BI-D, $12.35 for 25.


See plans for a large version of this trestle table.


Cutting List


Fig. A: Exploded View


Fig. B: Bending Form


Fig. C: Foot Mortises


Fig. D: Mortising Jig


Fig. E: Top Rail Details


Fig. F: Upright Details


Fig. G: Routing Jig


This story originally appeared in American Woodworker April / May 2010, issue #147.

April / May 2010, issue #147

Purchase this back issue.

Click on any of the images to view a larger version

1. Saw laminations to make the feet. Each foot contains seventeen 5/32" thick laminations.


2. Make a bending form to laminate the arched feet. Use a shopmade trammel to rout a pair of arches in a glued-up MDF blank. Remove the curved section in the center to create the two-part form.

 

Watch a video showing how to glue up a bent-laminated foot.


3. Test-bend the laminations without glue, and replace any that fracture. When the laminations draw together easily and tightly, without any gaps, they’re ready to be glued. Unclamp, apply glue to each lamination and then clamp them all back together.


4. The curve on the top surface of each foot must be consistent, so screw it to a “lazy Susan” jig and sand down the high spots.


5. Sand the bottom of each foot flat after cutting it to final length.


6. Stand the feet on a flat surface to lay out the mortises. Mark a centerline to use as a reference point.


7. Rout through mortises in each foot in three steps. First, use a jig to plunge-rout the mortises from the top, as deep as possible. The jig provides a flat surface for routing on the arched foot.


8. Next, tip the foot over and drill pilot holes deep enough to reach the mortises routed from the top.


9. Improvise a level platform to complete the mortises. Install a flush-trim bit, and plunge through the pilot holes. The bit’s bearing rides on the walls of the previously routed mortises.


10. Rout the bottom edge of each foot, to make it more graceful. Use the bending form (with a custom stop block attached) as a pattern to match the radius of the bottom arc with the top. This step creates tapers at both ends of the foot.


11. Round the uprights’ tenons to fit the mortises in the feet and top rails. Stop routing before the bit cuts into the tenon shoulder and complete the job by paring with a chisel or sanding by hand.


12. Shape the uprights’ bottom shoulders to fit the arched feet, using a shopmade jig and a pattern bit. A pattern bit is a plunge cutting flush-trim bit; its bearing is mounted above the cutters.


13. Routing leaves some work to be done to complete the uprights' arched shoulders. Remove the remaining waste by hand.


14. Complete the stringer. Cut dadoes for the uprights and shape its curved ends.


15. Assemble the base in stages. First, glue and clamp the stringer between the uprights. Work on a flat surface and mount the top rails to keep the uprights aligned.


16. Complete one end at a time. Apply glue and install the top rail and the foot. Then use clamps to gently draw the joints together.


17. Drive in the wedges as far as they’ll go. After the glue has dried, cut off the waste and rout the wedges flush.


18. Place a straightedge across the top during glueup, to make sure it stays flat when clamping pressure is applied.


19. Use a shopmade trammel and a straight bit to rout the top’s ends. Complete the job in several steps, by making incrementally deeper passes.


20. Attach the top after applying the finish. Center the base and use a brad point drill bit to mark the locations for the threaded inserts in the top. Drill holes and install the inserts. Then bolt on the top.


Filed under: , , , ,