Circular saws come in two different types. One is handheld and one is stationary (table mounted). This article is only about the handheld type.
The circular saw consists of a circular blade with saw teeth round the edge. The blade is connected directly to an electric motor and there is also some kind of fixture making it possible to guide the saw blade over the material being cut.
The saw blades can have different numbers of teeth. The more teeth the blade has the finer the cut will be but the cutting speed will also be slower.
Using a circular saw is great for cutting straight and relatively moderate curvature. The cut can be done real accurate. Also the surface finish is good when using fine teeth saw blades and relatively slow cutting speed.
The circular saw can be adjusted to cut different thicknesses of plywood and wood. With most saws this is an easy operation only requiring operating one handle. Also most circular saws can cut different angles making it easy doing bevel cuts.
As mentioned earlier the circular saw can be really helpful when cutting moderate curves. However making the curves requires that the saw is equipped with an anti-snag device. The device can be seen on the picture below.
When cutting with the circular saw the forward teeth cuts the plywood. Since the saw blade is circulating the teeth also have to pass through the plywood with the aft part of the blade. When the aft teeth are passing the material there is a risk they will snag forcing the circular saw to suddenly move up the cut.
This is more likely to happen if you are making curved cuts. Now with the anti-snagging device this is prevented so the aft of the saw blade won’t get into the cut. This means that the cut will be of better quality and more important your safety will not be compromised by any uncontrolled snagging.
Basically the handheld circular saw is a fine tool for home and backyard boat builders, but with this tool and any other electrical cutting tool it’s important to use it according to the safety and security guidelines given by the manufacturer. It’s also important to be careful and focused when using the tool so you avoid any accidents. Because remember the best way to avoid accidents is to think before you act.
Happy boat building,
Morten Olesen, Naval Architect