Hi there! Happy Monday!
Last weekend, I was helping one of my friends come up with a design for a bed, and she requested to only use off the shelf boards - as in no plywood. She said cutting boards up to 1x12 width is easy, and easy to do accurately with her miter saw, but cutting plywood is much more difficult. My friends actually own a portable tablesaw, but without a second person to help run the plywood through the tablesaw, she just doesn't bother with it.
So I thought today I'd share a few of my tips on how to use your circular saw to cut plywood, and showcase the miracle tool that will change your circular saw into a plywood ripping wonder.
Use the Right Blade
The best tip I can give you is to first upgrade to the right blade. Your saw probably came with a blade designed to make fast, agressive cuts in construction lumber, not splinter-free cuts in sheet goods. So, pick up a carbide-tipped blade that’s designed for making fine cuts. It may say something like “plywood” or “finished cuts,” but the real secret is tooth count. A higher tooth count will give you a smoother cut. Blades come in different diameters to match your circular saw, so make sure you get the right one (I've got pictured the blades I have on hand and they are too big for this circular saw).
Finished Side Down
Next, make sure you properly orient the sheet as you’re cutting. A circular saw cuts on the up stroke. That means the blade enters the wood from below, and exits at the top. That’s where most tear out occurs. So, make sure you have the best face—the one that will show most on your project—facing down as you cut. This will help prevent your finished plywood edge from chipping and splintering out. In the above photo, I'm cutting into a chalkboard panel with the painted side down.
Adjust Your Saw Blade Depth
Adjust your circular saw cutting depth to be just below the material. I do about 1/4" - so for ripping 3/4" thick plywood, I set my blade to about 1" depth.
Supporting the Plywood
Finally, when you cut sheet goods, you need to support the workpiece as you work - on both sides of the cut.
Long 2x4s over sawhorses work great - and you can cut a tiny bit into the tops of them as you cut your plywood. I actually keep several 2xs in my shop just for this task. (I'll get you those sawhorse plans very soon!)
But my favorite for cutting sheet goods is a sheet of thick rigid foam insulation. Just lay the plywood piece on the foam, and start cutting. The foam will support the plywood and you can cut into the top of the foam (as opposed to the top of your work table). Just make sure the piece you are cutting is not going to move on you as you work.
Using a Guide
It is very important to get accurate, straight cuts. But this is very hard to do freehand with a circular saw. When I need a perfect cut with a circular saw, I always use a guide.
The simpliest guide is just clamping a long, straight edge to the sheet of plywood, positioned so the foot of your ciruclar saw follows the straight edge. Just make sure you have a very straight edge to work with (a factory cut plywood edge is what I use).
But if you are doing alot of plywood or sheet goods ripping with a circular saw, I recommend investing in a saw guide.
The one I use and love is the Kreg Rip-Cut™ . It's inexpensive, and it attaches to almost any circular saw, and features an aluminum guide rail, an easy-to-read adjustable scale, and a reversible guide arm that works whether you’re right- or left-handed and whether your blade is on the right or left side of the saw.
It’s an incredibly easy, precise, and affordable way to break down large panels for almost any project.
There are also situations where it makes more sense to run the saw over the plywood as opposed to running the plywood through the tablesaw. Once we needed to rip dozens of sheets of 3/4" thick plywood into 12" strips. Instead of handling each piece of plywood four times through the tablesaw, we clamped multiple pieces of plywood together, and ran the lighter weight saw over the plywood using the Rip-Cut.
Whether you are tackling a full project out of plywood, or just need to accurately cut some 1/4" plywood for the back of a project, I hope these tips will make buidling faster and easier for you!
Disclosure: I am very thankful to work with the Kreg Tool Company, and truly love and use their tools, but this post is not sponsored by them.