Learn how to safely saw boards freehand, cut plywood with a straightedge guide and build a ripping jig for accurate cutting with a circular saw
Time An hour or less
ComplexityBeginner
CostLess than $20
Introduction
Learn how to use a circular saw to quickly and accurately cut long boards and plywood. Plus, we've included plans for a handy cutting guide attachment for your saw.
Even if your woodworking is limited to an occasional weekend project, you’ll eventually need to cut a narrow piece from a long board or sheet of plywood. Sawing long boards is easy if you own a table saw. But you can also do it accurately with a good circular saw. In fact, it’s usually easier to cut long pieces of plywood with a circular saw and a straightedge than to wrestle unwieldy sheets through a table saw.
A circular saw won’t cut as smoothly as a table saw, but with a couple of techniques, a little finesse and some practice, you can cut almost as accurately. Sound farfetched? Not really. Pros do it all the time. We’ll show you how to use a circular saw to quickly and accurately cut long boards and plywood and give you plans for a handy cutting guide attachment for your saw.
Circular Saw Safety
Making long cuts can be dangerous. Before you try it, be aware of the following safety precautions.
- Wear safety glasses and hearing protection, and avoid loose-fitting clothes. Tie long hair back.
- Set the saw blade to cut about 1/4 inch deeper than the wood’s thickness.
- Secure boards less than 6 inches wide with nails and wider boards with clamps.
- When you’re cutting, stand beside, never behind, the blade. Keep bystanders away from the area behind the saw.
- If the board starts to pinch the blade and cause it to bind, wedge the saw cut open with a shim.
- Make sure the blade guard is operating freely. Never block or wedge it in the raised position.
Tools Required
- Circular saw
- Corded drill
- Drill bit set
- Hammer
- Jigsaw
- Safety glasses
- Sawhorses
- Tape measure
Materials Required
- 1/2-in. plywood scraps
- 2 Wing nuts
- four 5/8-in. screws
- four 7/8-in. screws
- two 1/4-in. carriage bolts and washers
Watch How To Use a Circular Saw to Make Long Cuts
Project step-by-step (7)
Step 1
How to Saw Boards Freehand with a Circular Saw
Secure the board
This is a quick way to cut a few 2- to 4-in. strips, but if you have to cut narrow strips often, build the jig shown below.
This method results in a board of consistent width and parallel sides, whether the board you’re cutting from is straight or crooked. If you want to create a straight edge on a crooked board, mark the board with a straightedge or chalk line instead.
First, secure the board for cutting lengthwise by nailing it to sawhorses. Position one finish nail at each end near the board’s edge and away from the blade’s path. Pound the nails flush to the surface. Use 4D finish nails for 3/4-inch thick wood and 8D finish nails for 1-1/2 in. boards.
Caution: Don’t use this method if the board is splintery or if your finger is closer than 3 inches from the saw blade.
Step 2
Draw a guideline
With a combination square and pencil, draw a guideline parallel to the edge of the board. Press the fence of the combination square snug against the board as you slide it along.
Carefully position your hand and make the cut
Position your hand on the wide section of the saw shoe, not on the narrow side near the blade, and grip the shoe with your forefinger and thumb. Your forefinger acts as a guide. As you cut, direct pressure straight ahead through the saw’s handle and concentrate on the line.
If the saw starts to wander from the line, back up to about 6 in. behind where you first strayed from the line and start again. Before you squeeze the switch to restart the cut, make sure the saw blade is perfectly aligned in the kerf and maintain a firm grip in case the blade catches and jerks the saw.
Good follow-through is the secret to an accurate finish. Guide the saw beyond the end of the board as if the line continued.
Step 3
Cut Plywood with a Straightedge Guide
To make cabinet-quality straight cuts of plywood, all you need is a clamp and a perfectly straight board. The key is to align the straightedge at exactly the right distance from the cutting line and keep the saw shoe tight to the straightedge as you cut.
Also, learn how to make angle cuts with a circular saw.
Clamp a straightedge
Clamp a straightedge to a scrap of lumber for a circular saw rip guide. Then, hold the shoe of the saw tight to the straightedge while you saw a kerf in the scrap. Measure and record the exact distance between the straightedge and the inside edge of the saw kerf.
Tip: Clamp the straightedge on the piece of plywood you’ll be keeping. This way, if the saw accidentally wanders from the straightedge, it won’t ruin the piece you’re keeping.
Step 4
Measure and mark
Measure and mark the desired width of the cut board. Then, use the measurement you obtained to make a second set of marks for the straightedge on the “keeper” side of the first marks. Align the straightedge with the second set of marks and clamp it tight.
Step 5
Slide the saw’s shoe
Slide the saw’s shoe against the circular saw rip guide to rip the plywood. Press the saw firmly against the straightedge as you push it along to ensure a straight cut.
When you begin a cut, barely nick the plywood with the blade to make sure the blade just touches the outside edge of the cutting mark. Move both ends of the straightedge slightly to adjust the cut if necessary, then reclamp it. At the beginning of the cut, press the front of the saw shoe against the straightedge. At the end of the cut, keep the back of the shoe tight until the cut is complete.
Step 6
Building a Circular Saw Rip Guide
If you don’t own a table saw, you can build the guide shown here and attach it to your circular saw. It helps you cut narrow strips (1/2 inch to 6 inches wide) with near table-saw precision. You may have to modify it to fit your saw’s shoe. Building this circular saw rip guide takes about an hour.
Cut the plywood base and pieces carefully to ensure they have parallel sides and square corners. Make the slots and the hole for the blade and blade guard by first drilling 3/8-in. holes in the corners and then cutting between them with a jigsaw. Set the base over the fence and align one long edge. Then snug the rails up to the sides of the base and screw them to the fence with 7/8-in. screws. The completed fence assembly should fit snugly and slide easily. Connect the fence to the base with carriage bolts and attach the saw shoe to the base with small screws. Drill 5/32-in. holes in your saw shoe, and attach the guide with 5/8-in. screws.
Step 7
Using the rip guide
Measure between the blade and the fence to set the width of the rip and tighten the Wing-Nuts. Measure at both the front and back edges of the blade to align the fence parallel to the blade. Clamp or tack the board to sawhorses and slide the saw and jig the full length of the board.
