Most shop tools are designed for cutting through softer materials such as wood. Most plastics are denser than wood and have a tendency to crack if not cut with the proper tools and techniques. While many plastic retailers offer cutting services, cutting sheet plastic yourself can save time and money, and it's easy if you have the right tools. There are a number of simple ways to efficiently cut this material. For sheet plastic up to 1/2 inch thick, the simplest is to use a jigsaw or circular saw.
Things You'll Need
- Tape measure
- Grease pencil
- Metal straight edge
- Carpenter's square
- Scrap lumber
- Double sided tape
- Circular saw
Measure the sheet plastic using a tape measure. Leaving the protective backing on both sides of the sheet, draw a line where the plastic needs to be cut. Use a metal straight edge to ensure a clean line. Sheet plastic is often not square. If square cuts are required, use a carpenter’s square to check the sheet’s corners to make sure each corner meets at a 90-degree angle. Usually one corner will be close to square. Work from that corner.
Clamp a guide onto the sheet to ensure a straight cut. Use a piece of scrap lumber as the guide. Plastic can crack if the saw blade binds with the material, especially if using a circular saw. Therefore, guides are crucial for straight cuts. Make sure to measure the distance between the saw blade and the edge of the shoe (the saw’s bottom plate) that will ride against the guide. Curved cuts, done with a jigsaw, require no guides.
Slide the piece to be cut over the edge of the work table. If the piece extends 12 inches or more past the table’s edge, adhere a thin piece of plywood or scrap lumber with double sided tape to the bottom of the sheet to provide additional stability. Without the extra support or stability, the motion of the saw may cause the sheet being cut to vibrate or “chatter.” This can cause the sheet to crack or chip.
Turn on the circular saw or jigsaw prior to cutting. Ease it along the edge of the guide, slowly pushing it into the sheet. Apply slight pressure against the guide as the saw is pushed through the material to ensure it cuts a straight line. Use a workhorse or chair to support material that cannot be held safely while cutting.