To score and snap an edge, you need to be able to hang a section of the plastic off of the edge to snap it. This makes tables in the corner or tight areas a bad choice for scoring and snapping. If your polycarbonate is thinner than 1 in (2. 5 cm), you can score and snap it.
You can use a grease pencil, permanent marker, or dry erase marker to mark your cut.
You don’t need to press hard. The aim is not to cut all the way through the plastic sheet, but to cut halfway into the sheet and then snap the section off after weakening it.
If your sheet is really thin, you probably don’t need to do this.
Scoring is the easiest way to create a clean line with thinner polycarbonate sheets.
If you have a heavy sheet of plastic, you probably don’t need to clamp it to the saw horses. Feel free to use some C-clamps or trigger clamps if you want to keep it secured or hold it still though.
Measure the length you have to cut. If you want to cut multiple lines, mark all of them before cutting your first line. If you plan on cutting curved shapes or angles, your best bet is to use a jigsaw. If your polycarbonate is thicker than 1 in (2. 5 cm), you probably can’t score and snap it. Use a circular saw for these thicker plastics.
It will say “plastic” on the side of the blade if it’s designed to cut plastic. If you can, use a blade with 3-5 teeth for every 1 in (2. 5 cm) on the saw. Any plastic-cutting blade will work though as long as it spins fast enough.
If you have a steady hand, there’s no need to use a straight edge. Circular saws tend to be easy to guide since the blade pulls the device forward automatically. If you want to use both hands to operate the circular saw, you can clamp the straight edge to the work surface.
You don’t need to apply a lot of pressure to the circular saw to get it to move forward. Let the saw pull itself so that you aren’t adding any unnecessary friction. If you feel the saw buckle, or kickback, release the trigger. Pull it back a little bit. Press the trigger again and try to cut the line a second time.
Release the trigger on the saw and unplug it when you’re done. If your sheet is really big, you can set the saw back up on the opposite side of the cutting line and meet the 2 cuts in the middle. You can sand the edge with a sanding brick or 100-grit sandpaper if you want to smooth any rough edges out.
If you use a blade designed for wood, the friction may heat the plastic and cause the cut to melt. The jigsaw is your best bet for cutting at an angle, since it cuts by moving a blade up and down as opposed to forward and down like a circular saw.
You can also choose to guide your base plate freely.
You can clamp the plastic if you want instead of bracing the jigsaw, but you’re probably going to have an easier time moving the plastic at the same time that you rotate the jigsaw to make angled cuts.
Release the trigger on the saw and unplug it when you’re done. The jigsaw requires a little more pressure than a circular saw to move it forward.
