The Editor's Mailbox

Taking Risks in Furniture Design

Wed, 31 Oct 2007 16:42:46 GMT

When I downloaded the photos of my finished coffee table this morning, I realized why I so enjoy designing my own projects. There's nothing more satisfying than seeing your imagination come to life in a piece of furniture.

One of the greatest challenges of the design process is making something look right and also act right, because some projects might look great on paper but fall apart when fully assembled. It's almost like solving a puzzle: you lay out your pieces and start fitting them together until everything clicks. I figure someone out there in blogland might be able to glean something from the design process that went into building this table:

1. Work with what you've got: My primary requirement was to take advantage of the wood I had on hand, in this case a 12-foot long slab of flame birch that I found in a stack of air dried lumber in Vermont. My solution was to keep the design simple and let the figure in the wood take center stage.

2. Choose a few design elements: One of mine was to hide all end grain (almost). I've got nothing against it, but challenging myself with that requirement led to a really neat design.

3. Make sure it's stable and strong: Since I was using a wide piece of air-dried lumber, I knew wood movement was going to be a real concern. The breadboard end joinery I chose was mostly based on the need to let the parts move yet be sturdy for years to come, but also to challenge myself with something new. Similarly, I took great care to use rift-sawn lumber for the leg parts, even though it meant getting creative (and a little dangerous) with the milling process.

4. Finish the damn thing: Part-way through the project, I got really intimidated by the idea of cutting the mortise and tenons for the breadboard ends. As a result, I spent a few months just staring at a pile of parts. Finally, I came up with a more simple method for cutting the joint, and added the faux spline to cover my tracks.

If you'd like to follow the entire process (in reverse chronological order), click on the "Coffee Table Project" link below to see all 10 entries from concept to completion.

Now it's back to the drawing board.

Build a Table in Only 8 Months

Tue, 30 Oct 2007 15:33:15 GMT

Posted by Matt Berger

The problem with chronicling a project in a blog is that everyone who reads it finds out how much of a slacker you are. If you click on the "Coffee Table Project" link at the bottom of this entry, you'll see that it was more than eight months ago that I started making my flame birch coffee table.

Well, hopefully my latest progress on this project will revive your faith in me; I have been working on the breadboard end joinery for the past few weeks, assembled the parts, and last night I applied the first coat of Waterlox. Here's a photo essay on my progress:

Tenons by hand and machine
The first step to cutting the two massive tenons (shown above) for the breadboard-end joinery was to establish the tenon shoulders and cheeks. I did this with a router and tablesaw. First, I clamped a piece of plywood to the slab tabletop that guided the router and established the shoulder on both sides. Then I used a dado blade to cut away the remainder of the waste. At that point, I had one long tenon spanning the entire width of the tabletop, which I cleaned up with a shoulder plane.

Next, I used a handsaw to establish the tenon widths and chopped away the waste with a chisel. You'll notice that I left a short tenon spanning the full width of the tabletop. I figured it would help keep the tabletop aligned in the mortise while it shrinks and expands through the years.

Matching mortises by hand and machine
I had to make a design compromise in order to simplify the cutting of the mortises. I wasn't up to the challenge of locating the two mortises with a marking gauge, so I cheated and used a dado blade to cut a long groove across the entire length of the leg assembly, where it joined with the tabletop This groove matched the location of short tenon on the tabletop. I roughed out the deep mortises at the drill press and then cleaned them up with a chisel. The great thing about this technique was that I was able to use the groove as a guide for my chisel.

The downside to this technique was that the the groove extended to the outside edge of the leg assembly and would be visible when assembled. To disguise the groove, I borrowed a design element from the Greene Brothers: a neat little plug that is glued to the tabletop and mimicks a spline. This plug also disguises any seasonal movement.

Minimal Glue Required
The table spent a few days dry assembled and it was surprisingly sturdy even without glue. So I wasn't worried when it came time to actually glue the tabletop to the leg assembly. To account for seasonal movement, I only applied glue to a small section in the center of the joint. If you look closely at the photo above, you'll see two elongated holes in each tenon. Once the parts were assembled, I drove a small nail through the bottom of the joint into the elongated hole. This will keep the joint tight but still allow for side to side movement.

Clamping Pressure
As you can see in the photo above, the table is now assembled with glue. I always find this step of the process stressful because there's no turning back. But alls well that ends well. I did some final scraping and sanding over the weekend and the finish is going on nicely. Tune in tomorrow for a photo of the finished piece.

It's a Design Decision, Not a Mistake

Thu, 03 May 2007 18:43:50 GMT

Posted by: Matt Berger

The furniture making process, for me at least, is often just a series of compromises. A router bit slips, make it smaller. Wood tears out, make a patch. It reminds of the often-repeated phrase in woodworking: "It's not a mistake, it's a design decision." I would imagine that people who spend more time in the shop than I do have figured out ways to reduce the number of compromises (err, design decisions) in the life of a project, but I'm not there yet.

My latest compromise on this coffee table project I’ve been chronicling here over the past few months has to do with the mitered mortise and tenon joinery on the table legs. I made the tenons about 1 in. extra long so that I could bevel the end where it extended out of the mortise. However, a few false moves with my chisel and that extra inch of material was quickly wasted away.

The Legs are Assembled
The good news is that both leg assemblies are finished and I can move on to the final stage of construction: cutting the mortise-and-tenon joinery that will attach the tabletop to the leg assemblies, more accurately referred to as a breadboard end. As you can see in the photo above, I've already begun on the tenons. So far so good. I plan on taking my time with this one so that I don't have to make any more compromises.

One Down, Three to Go

Fri, 30 Mar 2007 20:31:27 GMT

The mitered mortise and tenon
Scroll down for a photo essay on one way to cut this joint.

Building the Jig is Half the Fun

Thu, 29 Mar 2007 13:52:10 GMT

I know I told you earlier that when I start a project I like to move swiftly through it so that I don't lose momentum. Well, I lied.

In fact, it's been more than four weeks since I did any work on my coffee table project, which I have been chronicling in this blog. The reason for the delay was to figure out a method for cutting the mitered mortise-and-tenon joinery in the leg assembly.

I Love This Jig!
About a week ago, I had an aha moment and came up with a simple tablesaw miter jig that allowed me to cut perfect mitered shoulders using minimal setup on the tablesaw. The challenge involved cutting the shoulders parallel and perfectly inline with each other.

Click to see the jig in 3D. Special thanks to Dave Richards for sending in these renderings of the jig. He says by email: "I had to sketch it out in SketchUp because I was sure I was missing something. It wasn't immediately clear why you have that stop on the right end of the miter gauge fence but after drawing it, it makes sense."

STEP ONE: Cut the first shoulder

A perfect miter. Mount a solid fence to a miter gauge set it to 45 degrees. Position the leg workpiece with one end butted up against a stop on the end of the jig. This first cut determines the shoulder. Make it count!

STEP TWO: Hog out the waste

Produce the shoulder. Move the leg workpiece down the miter fence and make successive cuts to hog out the waste and produce one shoulder of the tenon.

STEP THREE: Attach the 90 degree auxiliary fence

Cut opposing shoulder. Clamp an auxiliary fence to your miter fence that positions the leg workpiece 90 degrees to the previous cut. The workpiece is butted up against the miter fence and the stop.

STEP FOUR: Cut the opposite shoulder

Like magic. Amazingly enough, if your jig is tuned and accurate and your stock is properly milled, this next cut produces a shoulder that is exactly parallel and inline with the opposite shoulder.

STEP FIVE: Check your work

Measure twice cut once. Before proceeding with the rest of the process, make sure the shoulders line up on the outside and inside of the workpiece. If not, the final miter won't assemble properly.

STEP SIX: Hog away the waste

Finish up. Finally, hog away the waste by carefully moving the workpiece on the fence and past the blade making successive cuts.

STEP SEVEN: Fit the tenon

It works. The tenon should fit the mortise or be slightly oversized.

STEP EIGHT: Fit the tenon

Mark the tenon thickness. Using my mortise as a reference, I set my marking gauge to the desired tenon thickness and marked the workpiece on three sides. Squiggle lines help me remember what will be cut away.

STEP NINE: Cut the Tenon

Cut the tenon. Use a handsaw, the bandsaw, or a combination of the two to remove the waste. Cut shy of the line and then clean up the surfaces with a chisel.

STEP TEN: Clean up the joint

Cut to fit. With a sharp chisel, pare the mitered surfaces flush with the tablesawn shoulders and size the to final size.

STEP ELEVEN: Drive it home

Check the fit of the joint as you go until it fits just right.

Only three more corners to go. The rest of the joints that make up the table leg assembly will go together with floating tenons using the Festool Domino, which should only take a fraction of the time of this fussy joint. As always, post your comment below.