Mortising a Hinge with a Chisel

If you've got a houseful of doors to outfit with hinges, a router and a hinge template are what you need to get the job done quickly. But these tools are expensive, and they require setup time. If you're installing only one or two doors, you can mortise the hinges just as fast using a sharp chisel.

Unlike most cutting tools, a wood chisel is not fully sharpened at the factory. For fine carpentry work, the back of the chisel must be perfectly flat, and the beveled side must be razor sharp. Plenty of jigs are available to ease the sharpening process, or you can send your chisels to a local sharpening service.

Becoming proficient with a chisel is useful for more than just hinges. Among other things, the mortising and carving techniques shown here can be used to install strike plates.

Laying out the mortise

Follow the sequence below to lay out the mortise and mark the mortise using a pencil, a sharp knife, and an awl.

1. Locate the back of the hinge on the door. Using a combination square -- with 1/4 in. of blade exposed -- as a gauge, lay out the back edge of the hinge with a pencil.

2. Score along the ends of a hinge leaf. It's easy to control a sharp knife cutting across the grain. Scoring offers a definite starting spot for the chisel.

3. Change tools to score along the back of the hinge. Because it's less likely to follow the grain than is a knife, use an awl to score with the grain.

4. Before putting away the awl, use it to score the mortise's depth. A couple of scrap hinge leaves -- stuck together by a dab of hot glue -- serve as a depth gauge.

Working with a chisel

5. Start with a sharp chisel. An out-of-the-box chisel such as the one on the left is acceptable only for framing and other rough jobs. The chisel on the right had been hollow-ground on a bench grinder before it was honed on a series of oilstones; flat surfaces on the outermost edges only make resharpening quick.

6. A series of shallow cuts is the key to a precise mortise. Holding a 1-1/4-in. (or wider) chisel at about a 45º angle, cut across the grain in increments of about 1/4 in. Gently tap the chisel until the point of the blade reaches the depth score. With practice, you'll develop a rhythm that enables you to reach the desired depth without needing to glance at the line.

7. Horizontal slices remove the waste. Starting about 1/2 in. from one end of the mortise, place the blade (bevel side up) into the awl score and gently pare off the waste.

You may need to start the cut with a soft hammer tap, but finish with hand pressure only. Make sure the first cut is flat and smooth, then use the finished surface as a guide for subsequent cuts .