Bent Lamination Basics: A Bending Form

The bowed arms are so prominent in this Morris-chair design, so the figure and grain that shows on the top of each arm must be just right. Arms sawn from solid lumber would have a wild, distracting grain pattern. But laminating the arms allows you to control their look, choosing your best stock for the top and orienting it for the best effect. A laminated arm is also more stable than one cut from solid lumber, and concerns about short grain weakness disappear.

Laminating form keeps plies in line
Bent laminations can be tricky, but they don’t need to be. A fence and a stop on the form keep the plies aligned, and a simple caul applies even pressure over them. Using the right kind of glue will prevent the plies from creeping after you remove them from the form.

Start by making a laminating form. First, transfer the arm’s profile to a piece of 3/4-in.-thick MDF. The pattern for marking the curve won’t work here, because the arms are longer than it. Cut close to the line of the curve on a bandsaw and sand or file down to the line. You need eight 3/4-in. layers to get a form 6 in. wide. Use the first layer to make the remaining seven. Screw a fence to the side of the form and a stop to its front end. They will keep the plies aligned as you glue up the arms. Cover all of the working surfaces with packing tape to prevent glue from sticking to them.

Produced by: David Heim
Video by: Gary Junken; Editing by: Michael Dobsevage

Bent Lamination Basics: A Bending Form

The bowed arms are so prominent in this Morris-chair design, so the figure and grain that shows on the top of each arm must be just right. Arms sawn from solid lumber would have a wild, distracting grain pattern. But laminating the arms allows you to control their look, choosing your best stock for the top and orienting it for the best effect. A laminated arm is also more stable than one cut from solid lumber, and concerns about short grain weakness disappear.

Laminating form keeps plies in line
Bent laminations can be tricky, but they don’t need to be. A fence and a stop on the form keep the plies aligned, and a simple caul applies even pressure over them. Using the right kind of glue will prevent the plies from creeping after you remove them from the form.

Start by making a laminating form. First, transfer the arm’s profile to a piece of 3/4-in.-thick MDF. The pattern for marking the curve won’t work here, because the arms are longer than it. Cut close to the line of the curve on a bandsaw and sand or file down to the line. You need eight 3/4-in. layers to get a form 6 in. wide. Use the first layer to make the remaining seven. Screw a fence to the side of the form and a stop to its front end. They will keep the plies aligned as you glue up the arms. Cover all of the working surfaces with packing tape to prevent glue from sticking to them.

Produced by: David Heim
Video by: Gary Junken; Editing by: Michael Dobsevage
Chair plan: Brian Murphy, American Furniture Design Co.

Bent Lamination Basics: Creating the Bow Arm

Bent laminations can be tricky, but they don’t need to be. The form created in the last episode will keep the plies aligned and a simple caul will apply even pressure over them. Using the right kind of glue will prevent the plies from creeping after they are removed from the form.

Begin by resawing the white oak layers. It takes a finely tuned bandsaw to resaw wide lumber. To make things easier, Paolini starts resawing at the tablesaw and finishes up at the bandsaw. The tablesaw removes most of the material and its kerfs help guide the bandsaw blade through the arm. After resawing all of the laminates to 5/16 in. thick, he planes them to 1/4 in.

The best glue for laminating curved parts is urea formaldehyde (plastic resin). It has a long open time and doesn’t creep once dry. Those benefits outweigh its longer drying time. It is, however, a known carcinogen, so wear gloves and use a respirator or work in a well-ventilated area.

After coating the plies with glue, press them against the stop and fence. Add a flexible caul on top and start clamping next to the stop. Work progressively down along the form. Place a clamp every 2 in. You’ll need two dozen.

Paolini uses a piece of whiteboard for a caul, because it bends well and is glue-resistant.

Once both arms are laminated, scrape the glue from one edge, joint it, and rip the arm to width on the tablesaw, concave side up. Then cut the arm to length using a crosscut sled and a shim to get a square cut on the end.

Produced by: David Heim
Video by: Gary Junken; Editing by: Michael Dobsevage
Chair plan: Brian Murphy, American Furniture Design Co.

Stickley-Style Legs

The legs of a traditional Morris chair have four quartersawn faces. Lumber like that doesn’t grow on trees, but it can be made in the shop. There are several different methods to achieve the look, but the one Stickley used, which is the easiest by far, is to glue up a core of quartersawn lumber and then laminate two quartersawn veneers over the flatsawn edges of the core.

After the glue is dry, trim the veneers flush to the core with a router and flush-trimming bit. Then crosscut the bottom of each leg to square it up. Don’t worry about the tops right now.

Produced by: David Heim
Video by: Gary Junken; Editing by: Michael Dobsevage
Chair plan: Brian Murphy, American Furniture Design Co.

Mortising with a Router

Every joint in this chair is a mortise and tenon, the traditional Craftsman joint. They must fit well to get a square and strong chair. Here’s how to cut the mortises accurately with a router:

When making a mortise-and-tenon joint, Paolini usually start with the mortises. It’s much easier to fit a tenon to a mortise than the other way around. Cut all of the mortises, except the four in the arms. They’re laid out and cut after the tenons on the tops of the legs are made.

When routing mortises, Paolini matches the straight bit’s diameter to the mortise’s width so he doesn’t have to move the router side to side and risk tilting it out of square. Two fences (one the router’s edge guide; the other clamped on) keep the router on track.

When routing, remain consistent with the reference edges. When cutting the mortises on the legs, for example, reference the same fence against the outside face of each one. Otherwise, the position of the mortises will vary, resulting in sloppy joints and possibly a chair that’s out of square.

Paolini also doubles the parts for stable routing. Thin pieces, like the side posts, don’t provide a stable surface for a router. Clamp two or three of them together to get a wider bearing surface.

Produced by: David Heim
Video by: Gary Junken; Editing by: Michael Dobsevage
Chair plan: Brian Murphy, American Furniture Design Co.

Tenons on the Tablesaw

Every joint in this chair is a mortise and tenon, the traditional Craftsman joint. They must fit well to get a square and strong chair. Here’s how to cut the tenons accurately on the tablesaw.

Cut all of the tenons, except those on top of the legs, at the tablesaw using a dado head. First, cut the shoulders a hair deeper than the cheeks using a combination blade. Then, use a dado set to cut the cheeks. Support the piece with the miter gauge.

Cut a full tenon on the back of the upper rail; part of it will be sawed away later (see below).

Router-cut mortises have round ends, so the tenons get rounded over with the rasp portion of a Nicholson 4-in-hand file. Its smooth edges won’t mar the tenon shoulders, and its aggressive teeth make quick work of the rounding.

The tenons on the lower side rails will interfere with those of the front and back stretchers where they meet inside the legs. The best way around this is to insert the side rails into their mortises and trace the front and back mortises onto them. You’ll need to trim the tenons’ thickness about 1/8 in. in those areas.

Produced by: David Heim
Video by: Gary Junken; Editing by: Michael Dobsevage
Chair plan: Brian Murphy, American Furniture Design Co.

Side Assemblies and Through Tenons

The upper rail and the tops of the legs must be curved to match the bow of the arms. The easiest way to do this is to make a full-size drawing of the arm’s profile. You’ll use this drawing to make a pattern for marking the curve on the upper rails and legs.

To mark the curve of the arm on the upper rails and legs, dry-fit the side assemblies together. Align the bottom of the pattern with the bottoms of the rails. The ends of the pattern will align with the outside edges of the front and rear legs. Mark the curve on the inside and outside faces of the legs. And mark the inside of the legs on the pattern so you can realign it to mark the rail. Disassemble the side, and mark the curve there, too.

Cut the curve on the upper rail on the bandsaw. When you do this, the back tenon will be cut down to its final width.

To cut the tenons on the legs, first use a combination blade to cut all four shoulders square to the leg, in line with the highest shoulder (the one of the front of each leg). Then use a dado set to cut the cheeks. To cut down to the curved shoulder lines on the sides and back of the leg, use a chisel and mallet. I back-bevel the shoulders to ensure a tight fit with the bottom of the armrests.

Produced by: David Heim
Video by: Gary Junken; Editing by: Michael Dobsevage
Chair plan: Brian Murphy, American Furniture Design Co.

Cutting the Through Mortises

The mortises require careful layout. First dry-fit and clamp the side assemblies in preparation for cutting and fitting the arm mortises. Then clamp an assembly on the bench, inside face down with the tenons overhanging the edge. Set the arms on the tenons and press them snug against the shoulders. Mark the fronts and backs of the mortises directly from the tenons. Remove the arms and mark the mortise sides. Use a Forstner bit to remove most of the waste from the mortises, then pare down to the lines with a chisel.

Produced by: David Heim
Video by: Gary Junken; Editing by: Michael Dobsevage
Chair plan: Brian Murphy, American Furniture Design Co.