Although used for similar purposes, chisels come in many different shapes and sizes. Aside from the saw, the chisel is arguably one of the most basic and important blade tools in a woodworker’s tool kit. Chisels are used to cut into stock (wood-notching) as opposed to slicing completely through it. Due to it being a precision tool, chisels have a wide range of sizes as well as shapes. A seasoned carpenter will in all likelihood have a few dozen chisels of various widths and shapes. (Watch a short illustrated video on some standard wood notch joinery.)
How Composite Lumber Affects Woodworking and Notchwork Requirements
In recent years, due to the emergence of more stable composite building materials, the need for notching wood has decreased significantly. Wood in its natural state is prone to shape-change in the form of warping, twisting, bowing, etc. This is caused by the absorption and desorption of moisture when the stock is subject to humidity gradients. Woodworkers incorporate various notching techniques to minimize the movement of wood, and may also seal the surface to minimize moisture absorption.
But as mentioned earlier, modern composite materials such as structural composite lumber, are considerably more stable, and don’t require the same level of notchwork when compared to natural lumber. This, coupled with the fact that many hardwoods that are suited to furniture are becoming increasingly rare and expensive, is why composite lumber is being used more and more.
However, though composite lumber tends to have certain superior material properties, such as stiffness and stability, it can never quite take the place of natural wood in terms of aesthetic value. So it’s important to choose your materials based on the purpose for which it will be used. Composite lumber is superior when it comes to structural framing for a house, while natural wood is probably your material of choice when it comes to rustic furniture or the like, where the wood grain is an important and highly visible feature.
Although composite lumber is more stable, this doesn’t mean that there aren’t situations where you need to make notches — whether for joint integrity or simply gouging out material for fitting purposes. Of course, natural wood has a grain, the direction of which can be used to predict the behavior of wood as you apply the chisel. But composite wood on the other hand, not only has several perpendicular layers, but is also pressed with glue, often making it difficult to create clean precision notches.
Designate Tasks for your Chisels Based on Their Value
It’s recommended that you separate your chisels based on their value (cost, hardness, etc), as well as what you use them for. You probably don’t want to use an expensive chisel for rough jobs, or on lumber with lots of knots. Keep your high-quality chisels for precision jobs like intricate notchwork, and use your cheaper chisels for rougher notching. You also don’t need razor-sharp chisels for rough jobs, which means you don’t have to always be sharpening your cheaper chisels, saving you work.
How to Use Chisels the Right Way
Using chisels correctly will not only prolong the life of your chisel, but is key to ensuring your own safety as well as getting the results you’re looking for. I’ll list several pointers, some straightforward, some more advanced:
- Chisels are not screwdrivers. Do not use chisels to open lids, turn a screw, or as a scraper. A good rule of thumb is to never use the chisel on anything but wood.
- Sharp chisels cut clean and straight; dull ones bounce as you tap it with a hammer, and tear up the wood instead of cutting through it. Learn how to sharpen your chisels, if you don’t know how already. There’s nothing more frustrating than using a dull chisel for a project that requires a sharp one. (Watch video on how to sharpen a chisel.)
- Avoid knots if you can. This will minimize unnecessary chipping of your chisel blade.
- Ensure your workpiece is mounted securely and on a firm foundation. This is crucial to both safety and efficiency.
- Understand the difference between the beveled side of the chisel and the flat side, and what they’re each used for. Use bevel-side down when you want to dig down into the wood at an angle, and use flat-side down to cut through the wood in the direction of the flat surface of the blade. (Refer to example below.)
- Deep cuts or notches must be made in steps starting a safe distance away from the actual line to be cut, as the mechanical advantage of the chisel’s bevel will push the blade past the initial cut line. Taking the above illustration as an example, (1)begin by making a shallow precision cut (with the chisel or a utility knife) marking the square to be notched. Next, (2)begin removing material a few millimeters inside the cut line. After sufficient material has been removed, (3)make a deep vertical cut further inside the notch area. (4)Remove material by chipping diagonally toward the previous vertical cut from both directions. (5)Continue in this fashion until only the very outside remains. Now, as you tap straight down along the notch boundary (6), the mechanical advantage of the bevel will simply break off whatever material was left to the inside of the square, allowing the chisel blade to cut straight down without being pushed off course.