Of course, that doesn’t mean that perfect cuts are guaranteed with a circular saw. After all, even if you’re using a Skil model 5755 circular saw with its 2-beam laser guide, or a model 5600 with the Accu-Sight feature, it’s still up to you to get the saw set up, lined, up, and through the cut as cleanly and accurately as possible.
Here’s what I can tell you about how I get that done.
The Set Up — Regardless of how often you use your circular saw, the first thing you should do every time you pick the saw up is give it a good “once over.” Pay particular attention to the blade. Are all the teeth sharp and in good shape? IF not, replace it now. Trying to get “just one more cut” out of a worn-out blade never works out.
And be sure that the blade is the right one for the material you’re cutting. I use a general-purpose blade about 90-percent of the time. But when I need to cut expensive, veneered plywood, I’ll mount a 200-tooth plywood blade (74706) in the saw to get clean cuts. Likewise, if I’m going to rip a bunch of 2x12s to width, I’ll use a blade with a lot fewer teeth, because, in this case, I’m more interested in speed than clean cuts.
It’s also very important to set the depth of cut to match the wood. That means the gullets (those empty spaces between the teeth) should extend just below the bottom edge of the piece being cut. If you’re using a newer Skil circular saw, you can simply use the depth-of-cut gauge to make this adjustment. Otherwise, you’ll have to retract the blade guard, set the depth of cut, and compare the blade to the board. Did I mention that the saw should be unplugged while you’re doing this?
The Line Up — Now you need to lay out the cut line and decide if you’ll need a guide to help you hold that line with the saw. A guide can be anything from a rip fence (13896) to an ordinary speed square clamped to the board so the show of the saw can ride against it.
Of course, when cutting plywood or other sheet goods, you’ll need an edge guide longer than a speed square. There’s no shortage of tool guides that you can buy, and most of them are pretty good. But I still prefer to make my own.
My design is simply a 1x4 glued and screwed to a 12"-wide by ¼"-thick piece of hardboard.
The 1x4 is actually the edge guide; the hardboard is more of a base. The saw shoe rides against the 1x4, and the first saw pass will cut the hardboard to the proper width. Then, for each cut after that, you simply align the edge of the hardboard with the desired cut line and clamp the guide to the workpiece. You'll never miss.
I keep two of these homemade edge guides on hand: An 8'-long version for cutting plywood lengthwise, and a 4' version for cutting sheet goods widthwise
Hold the Edge — One thing that I struggled with for a long time was getting clean cuts, especially when cutting plywood with a veneer or plastic laminate face. No matter how careful I was, the edge would always chip or splinter.
Using the right blade, like I mentioned before, helps some. But with thin, brittle materials, even that isn't enough.
Eventually, I found three tricks that I now use to cut these materials.
First of all, most veneered plywood has one good face and one bad face. So, trick number one is to always cut with the good face down. That keeps the teeth cutting upward into the good face and makes it more likely that any tearout will occur on bad or “exit” face.
On the other hand, there are going to be times when you want to protect both faces from damage. The last two tricks — scoring and taping — help you do just that.
To score the cutline, you just a need a sharp utility knife and a straightedge. That edge guide I told you how to make is perfect for this. A drywall square is another good choice. Score the cut line on both sides of the board to protect both faces.
You can also apply tape over the cutline. A good painter’s tape works well for this. It will stick to most veneers and laminates, but won’t leave any residue behind when you peel it off. Again, you’ll need to tape both faces.
Maintain Control — The last two pointers I have for you are more about safety. But you might be surprised how the extra confidence these techniques give you will improve the quality of your work.
Number one, keep both hands on the saw whenever possible. In most cases, that means you’ll have to clamp the workpiece to sawhorses or a workbench. Take the time to do this. The extra control this creates will not only make the operation safer, but will also make it less likely the saw will get offline and make an errant cut.
Second, when making long cuts, especially in dimensional lumber that can be warped and twisted, hold the kerf open with shims or a “kerf keeper.” If the kerf starts to close up behind the saw, it can pinch the blade and lead to a kickback.
Full Circular — Well, like I said at the beginning, success isn’t automatic. But with the right circular saw and some sound techniques you’ll be well on your way. So grab your Skil saw and get “straight” to it.