There’s nothing to see in a blank board, until you put a saw to it. Then the subtleties of your stance, your grip pressure, your eye movement and your stroke become evident. A straight cut is one of the first techniques in woodworking where finesse is more important than brute force. Clean cuts aren’t merely a matter of aesthetics. They affect joinery, subsequent sanding and whether a project seems peaceful or a pain in the butt from the outset.
Start with material you don’t care about. Use a pencil and square to draw a line across the face of your board and extend it along the near edge so you have a second point of reference as you saw. Before you make a stroke, make sure the board is at a comfortable height and that you’re not contorted. One of the most common errors is to look only at the top line and not the line along the edge of the board below it. That will likely cause the blade to deviate from your intended cut. Instead, look back and forth between the top line and the edge line as you begin your stroke. Your initial strokes should be soft and muffled, as if you’re merely drawing the line with the blade, not forcing it through the cut.
You’ll apply too much pressure if you think doing so will help guide the blade. Too much pressure will actually cause the blade to deviate from its course and the line. Allow the saw to do the cutting. Your job is to guide it smoothly. If your blade deviates from the line, don’t try to force it back on course as you continue to saw. Instead, stop your stroke, reposition yourself and begin again with short strokes along the proper course. That’s not a failure; it’s a correction. Woodworking is more efficient when corrections are made early, rather than corrected later with sandpaper or wood filler.
If you have just 15 minutes to practice your straight cuts, here’s one approach. Spend the first couple of minutes drawing five or six lines across scrap boards, making sure each line is square and distinct. Then, without rushing, cut one line at a time and evaluate your results. Examine the offcut and the remaining edge of the board you cut. Did your blade deviate from the line as you cut? Was the kerf left behind plumb, or did it rake to one side? With one word, describe your result. It might be “rushed,” “smooth,” “angled” or “straight.” That simple exercise will help your hands correlate with your results. Finally, make one last cut, paying close attention to your work and using what you learned in your previous cuts.
If you’re not making progress, simplify your task rather than muscle through it. Cut narrower boards, softer woods or shorter lines. Shorter lines allow you to more easily see and correct your errors. You can also practice starting your cut without completing it. That may seem like a minute detail, but a bad start usually leads to a bad cut. If you find yourself consistently missing your intended kerf as you start to cut, check to make sure your saw is at the proper angle to the wood and that you’re not applying too much pressure, which will cause your shoulder to tense and your blade to deviate. A relaxed shoulder often means a straighter cut.
You don’t always need someone else to provide feedback on your work in order to improve. The wood itself provides feedback if you know how to read it. A cut that remains entirely on the waste side of your line demonstrates control. A burned line, a wandering kerf and an edge that requires a lot of correction all indicate a behavior you should examine. Keep a practice board with you at all times and date each cut as you make it over the course of several days or a week. After a week, compare those initial cuts with your more recent ones. You may not see a dramatic improvement, but you will see it in the edges and in the way your hands move.