Three ways to cut curves in wood
My tablesaw probably gets used more than any other tool in my shop, but it has one big limitation: it can’t cut curves. Not counting CNCs, lasers and other specialty equipment, there are basically three power tools available for making curved cuts in wood.
A scroll saw is great for cutting tight, intricate curves in thin material and is used mostly for decorative objects.
A band saw is is probably the most common tool for cutting curves in a woodworking shop but it is expensive, takes up space, and has its limitations.
A jigsaw can handle almost all the curved cuts you will want to make and more. It’s versatile, takes up no space, and is affordable. In fact, after decades of woodworking, I find myself using my jigsaw more and my band saw less. It’s that handy. I use a Dewalt DW317 jigsaw.
What is a jigsaw?
In the past, a jigsaw was often called a saber saw. Today, a reciprocating saw sometimes called a saber saw, but most likely it’s called a Sawzall, which is a brand name. Kind of like how people call circular saws Skil saws. And what we call a scrollsaw today used to be referred to as a jigsaw. Got it?
A jigsaw uses a small blade and cuts with an up and down motion. The thin size of the blades make it easy to cut pretty tight radius’s. And it’s handy for cutting holes, something a bandsaw can’t do.
It’s biggest limitation is that you can’t cut really thick lumber. Usually this isn’t an issue because I rarely need to cut curves in anything thicker than a 2×4.
The saw rests against your work piece on its base or shoe. On most saws this can be tilted to make beveled cuts, but I don’t think I’ve ever used that feature.
Most jigsaws also have variable speeds. This is useful for preventing burning as it cuts. In general, you can use a fast speed for pine and other softwoods, and a slower speed to reduce burning on hardwoods. To adjust the speed there is usually a dial, plus squeezing the trigger produces variable speeds on mine. I keep my dial set to its fastest speed almost all the time.
Orbital Action Cutting
A lot of jigsaws have an adjustment for orbital action cutting. When that is switched on, the blade pivots forward and backward in addition to going up and down. This makes for an aggressive cut and speeds up cutting on large pieces. The drawback is that is produces a more ragged cut. I rarely use the orbital cutting feature. Maybe occasionally for rough construction projects.
Bearing wheels push the blade forward and backward
Orbital cutting produces a ragged edge.
If you’ve never owned a jigsaw and looking to buy one, I’ll narrow your first decision for you. Only buy a jigsaw that uses T-Shank blades. Check on this before leaving the store.
In general, there are two types of blade shanks that hold to blade on the saw. The first kind, and probably the most common is a U-Shank. These might require a hex wrench or some other tool to install them into the saw. I used to have a saw like this, and it was a pain. Plus, the blades would sometimes fall out when I was cutting. I don’t think they are worth the hassle.
The second type are T-Shank blades like these. They quick-change attach to your saw in a second and stay very secure.
The teeth on jigsaw blades can point upward or downward. The blade produces a smoother cut on the side of the wood its cutting toward. I actually prefer the reverse blades that cut on the down stroke, since I usually draw my cutting lines on the good side of a board. And there are some occasions where this is even more important, like for cutting a hole into a counter top. But most blades sold cut on the upstroke. I’m not really sure why.
The teeth can be offset set at angles side to side like for faster, rough cutting. For woodworking, I mostly use less aggressive blades that have the teeth all in a line to get a smoother cut.
Blades are also sold in teeth per inch usually ranging from 6 TPI up to 24 TPI. A 10TPI blade is good for most woodworking applications. The fewer teeth per inch, the faster, but rougher the cut. A 24 TPI blades or higher are usually used for cutting metal or other materials. Narrow 20TPI blades are great for tight curves.
Using a Jigsaw
There are two things to consider when using a jigsaw. First, understand that the blade is unsupported on one end, so if you take curves too fast, the blade can flex causing the edge of your board to not be square with the face.
The other thing is to keep in mind the length of your blade and make sure it’s at least an inch longer than the thickness of the wood you want to cut.
It’s worth mentioning that a jig saw is one of the safest power tools you can use since the cutting blade is beneath the workpiece and your fingers are usually away from it. I usually support my workpiece just by holding it against my workbench and keeping my cut close to the edge. Sometimes the blade runs into the workbench, but that’s okay.
Unlike other saws, to make a cut with a jigsaw, personally I like to press the blade against the wood before starting the saw. I find it grabs better that way. If the saw is already running, it tends to slide around trying to find the cut line. Then just follow your line. You’ll get a feel for how fast you can push the saw. There’s no need to rush it, but I find that you can cut larger, sweeping curves smoother if you go a little faster.
The main thing to be conscious of is keeping the base of the saw pressed against the board. It’s easy to lift it up without realizing it, causing the edges to not be square.
Slow your feed rate for tighter curves. If the curve is too tight for the blade to turn, I like to kind of carve with the blade. You can even carefully sweep the saw side to side and nibble away at the wood. I like to think of it as a shaping tool as much as a saw.
Cutting Holes With a Jigsaw
A jigsaw is a must-have tool for cutting holes or other inside shapes, Something you can’t do with a bandsaw. Drill a hole, drop your blade into it, and start cutting. If you want to cut a hole with square corners, drill holes in two corners and connect them.