Cutting the Half-Lap

Accurate layout makes sawing and paring lap joints easier.

By Chris Gochnour #252–Jan/Feb 2016 Issue

Synopsis: A good starting point to learning the skills to cut joinery by hand are half-lap and T-lap joints. These simple joints bring home the most important lesson about hand-cut joinery: Accurate layout is a must. You’ll also get to practice cutting and paring cheeks and shoulders, two tasks involved in just about all furniture joinery.

To me, there’s nothing more satisfying than building a piece of furniture using hand-cut joinery. But cutting joinery entirely by hand can be an intimidating task. I think that’s because we tend to think of the ideal joint, one brought together with a nice friction fit and no gaps. But this ideal joint is not an insurmountable mountain. Break it down, and you realize that it’s just a series of small steps. With a bit of practice, tackling the joint one step at a time, you’ll soon become proficient.

A good starting point to learning the skills to cut joinery by hand are half-lap and T-lap joints. These simple joints bring home the most important lesson about hand-cut joinery: Accurate layout is a must. You’ll also get to practice cutting and paring cheeks and shoulders, two tasks involved in just about all furniture joinery. Once I show you the secrets to these basic joints, you can apply the skills to more complicated ones.

1. Begin with precise layout. A knifed line is far more accurate than a pencil line for this joint, and will help you pare the joint to fit later. Also, because the stile overlaps the rail on the front of the frame, lay out the joint on the back of the stile and on the front of the rail.

Mark the shoulder. Use a square and knife to get a clean, deep (1⁄16 in.) cut across the grain. The width of the mating part determines the shoulder’s location. — **Mark the shoulder. Use** a square and knife to get a clean, deep (1⁄16 in.) cut across the grain. The width of the mating part determines the shoulder’s location.

Wrap it around the edge. To locate the cut, put the point of the knife in the kerf and bring the square up to it. Scribe halfway down the edge. — **Wrap it around the edge.** To locate the cut, put the point of the knife in the kerf and bring the square up to it. Scribe halfway down the edge.

Use a marking gauge for the cheek. Scribe a line in the exact center of the part’s thickness. Mark the end grain as well. — **Use a marking gauge for the cheek.** Scribe a line in the exact center of the part’s thickness. Mark the end grain as well.

2. Saw the shoulder. Here’s where the deeply cut layout lines pay off. After some careful paring, they become guides to help you track the saw for a straight and plumb cut.

Cut a groove at the shoulder. With a wide chisel 1⁄16 in. from the shoulder line, cut down to the scribed shoulder, creating an angled notch. — **Cut a groove at the shoulder.** With a wide chisel 1⁄16 in. from the shoulder line, cut down to the scribed shoulder, creating an angled notch.

Cut the shoulder to depth. The saw’s teeth should just kiss the vertical wall cut by the marking knife. Keep an eye on both edges of the part so that you don’t cut below the cheek line. — **Cut the shoulder to depth.** The saw’s teeth should just kiss the vertical wall cut by the marking knife. Keep an eye on both edges of the part so that you don’t cut below the cheek line.

3. Cut the cheek in stages. Making long, accurate ripcuts with a backsaw can be tough. Breaking down the sawing into smaller steps increases accuracy and reduces cleanup later.

Create a shallow kerf on the end grain. Start at the far corner using the scribed line as a guide. Cut just a bit deeper than the teeth. — **Create a shallow kerf on the end grain.** Start at the far corner using the scribed line as a guide. Cut just a bit deeper than the teeth.

Make a diagonal cut down one edge. At first, follow only the vertical line on the part’s edge. Then come in across the board’s width until you reach the halfway point. — **Make a diagonal cut down one edge.** At first, follow only the vertical line on the part’s edge. Then come in across the board’s width until you reach the halfway point.

Flip and repeat for the opposite edge. After you’ve cut down to the shoulder, bring the saw horizontal and cut away the remaining triangle of waste. — **Flip and repeat for the opposite edge.** After you’ve cut down to the shoulder, bring the saw horizontal and cut away the remaining triangle of waste.

4. Clean up the joint. No matter how good you are with a saw, you’re not perfect. That’s OK. With a sharp chisel in hand and accurate layout lines as a guide, you’ll bring the half-lap together without gaps.

Use a wide chisel for the cheek. Work from the edge toward the middle, then turn the part around and come in from the other edge. Pare down to the scribe line. — **Use a wide chisel for the cheek.** Work from the edge toward the middle, then turn the part around and come in from the other edge. Pare down to the scribe line.

Work down on the shoulder. Place the chisel into the scribed shoulder line and push down. Use one hand to keep the cutting edge in the scribe line. — **Work down on the shoulder.** Place the chisel into the scribed shoulder line and push down. Use one hand to keep the cutting edge in the scribe line.

The big payoff. Careful layout followed by paring to the layout lines results in a joint that fits tightly and looks great. — **The big payoff.** Careful layout followed by paring to the layout lines results in a joint that fits tightly and looks great.

Cutting the half-lap

From Fine Woodworking #252

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Comments

hubola | Jan 27, 2017 05:02pm | #1
I am in the process of building twenty four stall doors, each one using this joint. Much quicker and smoother to use a dado blade on both the radial arm and table saw and clean up chisel, shoulder plane, chisel plane, whatever is needed. Layout comes right off the pieces being used.