Plexiglass is an excellent alternative to glass, especially if you have safety concerns. But while the material is stronger and much more durable than glass, it can still crack if you cut or drill into it incorrectly. So, what’s the proper way to cut plexiglass?
The best method to cut plexiglass depends on the thickness of the material. Thicker sheets are best cut with a simple scoring knife, those with medium thickness can be cut by a scroll saw, and the thickest sheets should be cut with handheld rotary tools, like jigsaws or circular saws.
Plexiglass sheets come wrapped in protective paper, and it’s important to keep them wrapped for as long as possible to prevent scratches. Let’s look at how you can cut plexiglass by hand, which handheld tools are the best for the job, and how you can achieve a smooth and polished finish, so that you can finish all your DIY plexiglass projects without a hitch.
Can You Cut Plexiglass by Hand?
Plexiglass is extremely strong and flexible, and its wide versatility makes it perfect for use in several everyday applications. Given the material’s outstanding sturdiness, it would make sense if you could only cut it with specialized machinery.
Luckily, that’s not the case. With the help of the right household tools, you can easily cut plexiglass by hand and complete all sorts of DIY projects.
Which Handheld Tools Are Best?
If you’re not familiar with any power tools, then cutting plexiglass by hand is your best option. You’ll just need a plexiglass sheet (on Amazon), clamps, a scoring knife (also on Amazon), and a straightedge ruler that’s longer than the cut you plan to make. However, keep in mind that this method is only suitable for straight cuts.
So, if you’re planning on cutting thicker sheets of plexiglass or more complex shapes, you’ll need to use power tools. It’s best to use a scroll power saw or a table saw, and fit them with blades that are specifically designed for cutting plexiglass, aluminum, or copper.
Regardless of the power tool you choose, just make sure you use a blade that’s suitable for the task, preferably one that has at least ten fine teeth per inch.
How to Score Properly
Strangely enough, thicker plexiglass sheets are the easiest to cut. Here’s how you can properly score and cut the material by hand:
- Grab a utility knife, a grease pencil (on Amazon), and a straightedge metal ruler.
- Use the pencil to mark the plexiglass at all the places you want to cut it.
- Position the ruler against your marked line and then repeatedly draw the knife down its edge. Make sure you gradually increase the pressure with every pass.
- Keep repeating this step until there’s a deep line in the material. You might need to make ten or twelve passes to properly score the plexiglass. Then, turn over the slab and repeat the scoring process.
- Place the plexiglass right over the edge of the work table, making sure that the scored line is perfectly parallel to that edge.
- Firmly weigh down or clamp the side of the plexiglass that’s on the work table, and then apply sharp downward pressure on the side that’s hanging over the edge. This should break the plexiglass cleanly.
How to Cut Your Plexiglass
If you have an extremely thin piece of plexiglass or want to cut complex shapes, you won’t be able to score the material with a simple utility knife. These thinner plexiglass sheets are extremely vulnerable to chipping or melting, so the only way to properly cut them is with a handheld rotary tool:
How to Cut Plexiglass With a Jigsaw
If you want to cut a few curves in your plexiglass, you won’t be able to use the simple score and snap method. The method is especially difficult when you’re making circular porthole windows or cutting other unique shapes. So, in these situations, it’s best to use a jigsaw that’s equipped with a sharp acrylic blade.
The most important thing to remember when cutting plexiglass with a jigsaw is to maintain a low speed. If you start cutting at a very high speed, the blade will overheat and melt your plexiglass, completely messing up your project.
Before you start using the jigsaw, use a permanent marker to mark the cut line on the plastic wrapping covering the plexiglass. Then, apply painter’s tape (on Amazon) on top of the cut line to prevent the sheet from cracking.
Position your jigsaw blade against the plexiglass sheet and slowly move along the marked line. However, if you’re making several cuts, then make sure you let the blade cool properly between each one.
How to Cut Plexiglass With a Circular Saw
If you want to cut straight lines on thicker plexiglass sheets, you may not be able to get a clean break by scoring and snapping the material. In this case, a miter saw (on Amazon), table saw, or circular saw with the right plexiglass blade may be a better option.
Cutting plexiglass with a miter or table saw is almost the same as cutting wood, as long as you use the right blade — preferably one that’s specially designed to cut plastic or plexiglass. It may also help to apply painter’s tape over the cut line first.
If you’re cutting plexiglass with a circular saw, then it’s better to support the material with a rigid foam insulation sheet. This will help prevent the plexiglass from vibrating and cracking under the weight and pressure of the saw.
Place the foam insulation under the plexiglass sheet, and mark the cut line. Then, attach a plastic cutting saw blade to your circular saw. It’s also advisable to use a circular saw guide or a circular saw jig to ensure clean, straight cuts and to prevent your blade from wandering.
Tips for Smoothing and Polishing
Regardless of the method you use to cut plexiglass, you’ll still need to smooth down and polish the resulting cut-out piece, especially if you’re worried about your project’s aesthetics. For proper smoothing and polishing, you’ll need a few things:
- A rubber or wood sanding block
- Several pieces of sandpaper (on Amazon), ranging between 120 and 600 grit
- A polishing compound specially formulated for plastic
- A power drill attached with a buffing pad
First, soak the sandpaper in water for fifteen minutes or longer. You can even let the sandpaper soak overnight if you have time to do so. Then, start sanding the plexiglass with the 120-grit sandpaper, and gradually increase grit levels as the material’s edge gets smoother.
Keep sanding the plexiglass until you reach the 600-grit sandpaper and have an exceptionally smooth edge. Lastly, apply the polishing compound onto your plexiglass and use the buffing attachment to buff the material to a perfect polish.