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Cutting Plastic: Which Saw Should You Use for Tubs, Pipes and Sheet?
For most plastic jobs, a jigsaw with a fine blade and the pendulum action switched off is the handiest choice: it cuts straight lines, curves and holes. Long straight cuts in sheet go faster with a circular saw, and for thick tubs, water butts or pipes in awkward spots, reach for a reciprocating saw.
When cutting plastic, work at a calm, steady pace so the material does not melt onto the blade.
What will you learn in this article?
- Which saw suits which plastic item?
- How do you cut plastic with a jigsaw?
- When should you use a circular saw?
- When is a reciprocating saw useful?
- Can you cut plastic by hand?
- Why does plastic melt when you cut it?
- How do you stop plastic chipping and cracking?
- How do you finish the edge?
- How do you cut plastic safely?
- Frequently asked questions about cutting plastic
- In short: cutting plastic
Which saw suits which plastic item?
Plastic jobs usually involve a specific object: a storage box, water butt, pipe, uPVC window profile or a sheet for a greenhouse or shed. Choose the saw based on the shape.
| What you are cutting | Best saw | Why |
|---|---|---|
| Flat sheet, straight cut | Circular saw or jigsaw | Straight and quick |
| Sheet with a curve or cut-out | Jigsaw | Manoeuvrable |
| Tub, water butt, bucket | Jigsaw or reciprocating saw | Copes with curved shapes |
| Pipe or profile | Fine-toothed handsaw, hacksaw or reciprocating saw | Easy to guide around a pipe |
| Recess or small cut-out | Multi-tool with a plunge-cut blade | Cuts into a flat surface from the middle |
| Thin plastic or film | Craft knife or scissors | No sawing needed |
How do you cut plastic with a jigsaw?
The jigsaw is the most versatile power tool for plastic. With the right blade you can cut both straight lines and curves.
- Choose a blade for plastics or a fine metal-cutting blade. Fine teeth give a smooth edge.
- Switch off the pendulum action. With the pendulum on, the blade tugs at the plastic and the edge chips or cracks.
- Keep the base plate pressed firmly on the material. On a curved tub it is better to cut in short sections, so the base plate always sits flat.
- Start at a medium speed and turn it down if the plastic starts to melt.
A cordless jigsaw from the Maxxpack 18V range is pleasant to use on loose items, because you can easily walk around them.
How do you cut a hole in plastic?
First drill a hole in the waste area that is big enough for the jigsaw blade. Put the blade in the hole and cut out the shape. For round holes you can also use a hole saw at a low speed. A multi-tool with a plunge-cut blade is useful for a rectangular opening in a flat surface, such as a plastic panel.
When should you use a circular saw?
A circular saw is ideal for long straight cuts in sheet material. It cannot cut curves. Use a fine-toothed carbide-tipped blade that is suitable for plastics, support the sheet well and cut along a guide. Leave any protective film on until the cut is finished.
When is a reciprocating saw useful?
A reciprocating saw looks a bit like a jigsaw, but the blade sticks straight out from the front of the tool. That lets you reach places a jigsaw cannot, such as a pipe against a wall or an old plastic water butt you want to cut into pieces for the tip.
- Choose a fine blade for plastic or metal.
- Clamp the material firmly. A reciprocating saw vibrates a lot and can drag a loose object along with it.
- Cut at a steady speed. Too fast and the plastic melts, too slow and the blade snags.
A reciprocating saw is less accurate. Use it for rough work and demolition, not for an edge that will be on show.
Can you cut plastic by hand?
Yes. For pipes, profiles and small pieces, a fine-toothed handsaw or hacksaw works well. Use a mitre box for a square cut. Saw with light pressure and long strokes. That keeps the edge neat and stops the plastic heating up.
You do not need to saw thin plastic, such as film or a thin sheet. Score it deeply a few times with a sharp knife along a steel rule, then snap it over a straight edge.
Why does plastic melt when you cut it?
Plastic has a lower melting point than wood or metal. Friction heats the blade and the plastic sticks to it. You can tell from lumps on the blade or a kerf that closes up again behind the saw.
How to prevent it:
- Lower the speed.
- Use a sharp blade. Replace it once plastic starts to stick.
- Keep moving. Holding a running blade in one spot creates a melted patch straight away.
- Let the blade cool after a long cut and remove stuck residue once the tool is switched off.
How do you stop plastic chipping and cracking?
Hard, brittle plastic, such as acrylic or old plastic that has been weathered by sunlight, can crack. You can prevent that with:
- A fine blade with the pendulum action off.
- Clamping the material firmly, close to the cutting line.
- Masking tape over the cutting line. Draw the line on the tape and cut through it.
- Starting gently. The first few centimetres are the most sensitive.
How do you finish the edge?
Remove burrs and melted ridges with a sharp knife, a deburring tool or a fine file. Then sand with fine abrasive paper. Wipe away dust gently with a soft brush or cloth so you do not scratch glossy plastic.
How do you cut plastic safely?
- Wear safety glasses. Plastic chips fly a long way.
- Wear work gloves and ear defenders.
- Always secure the workpiece with clamps or in a vice.
- Work in a well-ventilated space. Melting plastic gives off fumes. If you smell burning, stop and lower the speed.
- Never cut into a drum or container that has held chemicals or fuel unless it is completely empty and clean.
- Remove the battery from the tool before changing the blade.
Frequently asked questions about cutting plastic
What is the best saw for plastic?
For most jobs, a jigsaw with a fine blade and the pendulum action off is the best choice. A circular saw is better for long straight cuts, and a reciprocating saw for rough work in awkward spots. Pipes are easy to cut with a fine-toothed handsaw.
How do you cut a plastic water butt or tub in half?
Mark the line all the way round with tape. Drill a starter hole and cut along the line in short sections with a jigsaw or reciprocating saw. Secure the water butt so it cannot roll away.
Can you cut plastic with a wood blade?
You can, but the result is usually poor. A wood blade has coarse teeth that make the plastic crack and leave a ragged edge. A blade for plastics or a fine metal-cutting blade gives a much cleaner cut.
Why does my cut edge turn white or ragged?
A white or ragged edge is often caused by a blade that is too coarse, the pendulum action being on, or too much vibration. Some plastics also show white stress marks. Choose a finer blade, clamp the material more firmly and cut more slowly.
In short: cutting plastic
A jigsaw with a fine blade and the pendulum action off handles most plastic jobs, from straight cuts to curves and holes. Use a circular saw for long straight cuts in sheet, a reciprocating saw for rough work in tight spots and a fine handsaw for pipes. Keep the speed moderate, clamp the work and finish the edge with a file and fine abrasive paper.
