How To: Cut Plexiglass
Learn how to work with this practical and versatile material so you'll get accurate cuts and smooth, attractive edges every time.
From picture frames to tabletops, plexiglass (also known as acrylic) serves as a cost-effective, shatterproof substitute for glass in a range of applications. In fact, due to its light weight and durability, many do-it-yourselfers prefer plexiglass, not least because it can be cut and shaped with common workshop tools. Versatile and tough though it may be, however, plexiglass isn’t perfect. For one thing, it scratches easily. That’s why sheets of the material come covered in a thin layer of protective film. The other downside? Homeowners who don’t know how to cut plexiglass can be intimidated by the material at first—but we’re here to help! When cutting plexiglass, leave the film in place as long as possible to avoid marring the surface. Second, bear in mind that even if you’re careful, it can be difficult to cut plexiglass without leaving a rough, irregular edge. If your project requires a clean edge, expect to devote at least some energy into smoothing the finish. In comparison, cutting the plexiglass to size is fairly easy. Continue reading for details on how to cut plexiglass—the right way.
For a thin sheet of plexiglass—that is, material up to about 3/16-inch thick—use a scoring method not dissimilar from the technique used to cut actual glass. First, lay the sheet on a flat surface and, using a yardstick and a permanent marker (or a grease marker), measure and draw the line you wish to cut. Next, hold the yardstick to the marked line, and run the dull side of a utility knife along the yardstick to score the sheet. Score again and again, as many as 10 or 12 times, until you have made a deep groove in the plexiglass. Flip over the plexiglass, and score the opposite side in the same manner. To finish, hold the scribed line to the edge of your work surface, and secure the plexiglass in place with a clamp. Then, with sharp downward pressure, snap off the portion of the plexiglass that extends beyond the work surface.
For thicker sheets of plexiglass, cut with a power saw—be it a circular saw, saber saw, or table saw. (To cut anything but a straight line, opt for a jigsaw.) No matter which type of saw you choose for the task, it’s critically important to use the right blade. There are special blades designed expressly for acrylic, but any metal-cutting blade with carbide tips can do the trick. Before committing to one blade or another, double-check that its teeth are evenly spaced, with no rake, and of uniform height and shape. After readying your tool, measure and mark the plexiglass, then cut as you would any other material, clamping if appropriate. One note of caution: If the blade overheats, the material may chip or crack. Proceed accordingly, water-cooling the blade or pausing your work for a few minutes as needed.
Polishing Cut Edges
Whichever cutting method you choose, you may find that the cut edge doesn’t look terribly attractive. If the cut edge would be visible in your application, take the extra time to sand and buff out the imperfections. Note: You can use a handheld power sander, but as wet-sanding typically achieves the best results, we recommend manual sanding. Start the process with 120- or 180-grit waterproof paper, in combination with a wood or rubber sanding block. As the plexiglass becomes smoother, transition to successively finer grits. Finish by sanding with 600-grit paper. Once you are satisfied with the appearance of the edge, move on to buffing. Outfit your electric drill with a buffing pad and, after applying a polishing compound (formulated for plastic), bring the plexiglass edge to a perfect polish.
Every building material comes with a set of quirks and nuances that you can master with practice. Fortunately, it doesn’t take long for do-it-yourselfers with woodworking experience to learn how to cut plexiglass. Although for the time being, you may only need to cut a piece of acrylic down to size, learning to work with this versatile, transparent material opens up a new universe of DIY possibilities that you can explore in myriad projects for years to come.