Popular Woodworking 2006-02 № 153, страница 61
Grinding down the side bevels on a stock chisel is a quick process when using a motorized grinder. Set the tool rest close to the wheel and work the first 1" of the tool. Quench the blade to avoid overheating the steel.
tools are sharp and in tune. I'm sure that you've read articles on the importance of tuning hand planes. Most chisels need tuning, too. But I think you'll find the process of tuning chisels to be less time-consuming than tuning a plane. Best of all, the quality of your work will improve. Read on and I'll explain the problems with many chisels and how you can quickly and easily modify them before tackling that next set of dovetails.
Signs of a Good Chisel
A good chisel should be a well-balanced extension of your hand. When chopping (such as when removing the waste between dovetails), the chisel is held vertically (or nearly so) and struck with a mallet. The extra force of a mallet is required to push the chisel edge through tough end-grain. But just because a mallet is used doesn't mean that chopping is a crude process made with brute force. On the contrary, the force of impact should be precise and controlled. And for the greatest control, the chisel should be gripped not by the handle, but on
the shaft with the hand braced on the work, just as you grip a pencil. (Try gripping a pencil at the eraser end and signing your name; you can't get the control that you normally do.)
But what does the grip have to do with fine-tuning the chisel? It has more than you might think. Unfortunately, many chisels are too long and heavy for effective chopping; the extra mass and length make the chisel top-heavy and difficult to control. Although long chisels are an important part of a woodworker's tool kit, they're for paring, not chopping. Besides, most of today's chisels are too short for effective paring; but more on that in a minute.
Compounding the length and balance problems is that the ends of the handles on many chisels are excessively rounded. When chopping, as the mallet strikes the round surface, it has a tendency to glance off. The solution is to change the shape; the end of the handle should be slightly crowned, not rounded. A crowned end will absorb the impact of the mallet and direct it to the cutting edge.
Now let's examine the other
end of the chisel, adjacent to the cutting edge. Like many chisels that were manufactured years ago, most of today's chisels are bevel-edged. In other words, the sides of the chisel are chamfered. The reason for the beveled edges is so that you can easily cut into an acute corner, such as the space between dovetails. However, the problem with many chisels is that the sides are not beveled nearly enough. To be effective the sides should be beveled to almost a knife edge. Examine the chisels from your kit closely and you'll most likely see that a square portion of the sides
remains. As a result, each time that you make a cut next to a dovetail, the corners of the chisel crush the adjacent surfaces and spoil the crisp appearance of the joint.
Fortunately, the excessive length, rounded ends and square sides are all easily corrected. And it takes just a few minutes to tune the tools and fix the problems. The results are well worth it, too. After modifying a chisel you'll be surprised at how much easier it is to use. In fact, your skill level will seemingly jump up a notch or two. First let's address the problem with the excess length.
Fixing Excessive Length
Years ago, many chisels were available in two lengths: The long length was for paring; the shorter length was for chopping with a mallet. For more than 20 years I've used the Stanley No. 750s. These venerable socket chisels were manufactured by the thousands up until the late 1960s. The short length, around 9", and light weight make them perfectly balanced. And remember, balance is the key. In addition, the
Most chisels today are the wrong length for chopping or paring. Above, the short chisel (left) is the right length for chopping. The long chisel (right) is the right length for paring. The Marples chisel (middle) isn't a good length for chopping or paring.
Cutting off the extra handle length dramatically improves the balance of the chisel.
Popular Woodworking February 2006