With good tools and the right method, you can process acrylic sheets properly. It should be noted here that cast acrylic can be processed much more easily than extruded acrylic. If you are going to carry out much work on the acrylic, we strongly recommend using cast acrylic as the chance of tearing and breaking is minimal. But with the necessary precautions, you can cut extruded sheet reasonably well. Acrylic can be processed by sawing, milling, drilling, sanding and polishing. These are the most important how-tos for processing acrylic sheet.
Requirements for working acrylic:
To drill acrylic, you must use HSS (High-Speed Steel) drill bits and a variable speed drilling machine. Place the acrylic sheet on a flat surface where the drill can run out, for example, a piece of wood. Optionally, you can place some slats next to the borehole (where the drill enters) that are clamped onto the acrylic sheet with glue clips. For example, the sheet must be pressed down well at the height of the hole as if it rides up during drilling, it will break or crack.
If you want to mark the position of the hole, do not mark it on the protective film, but rather stick a strip of masking tape at the desired location. By doing this, you prevent the marking pen from scratching the acrylic. Run the drill at three-quarters of its maximum speed and press lightly on the drill. Acrylic is best machined without the drill taking out chips and without the material getting hot and sticking.
Acrylic sheet can be cut with a circular saw or a jigsaw. For both, you must use a saw blade with a fine tooth. If you want to mark the cutting line, first stick a wide strip of masking tape on the cutting line, at the top and bottom! The tape must be wide enough for the sole of the jigsaw so that it does not damage the surface of the acrylic.
If you use a circular saw, you must use an alternating-tooth saw blade with many teeth, for example, a Widia saw. With a circular saw, you can cut both cast and extruded acrylic, but with a jigsaw, you can only cut cast acrylic. When using the jigsaw, we recommend that you choose a special saw blade for plastic, or otherwise a saw blade for non-ferrous metals. It is necessary for the jig saw’s pendulum position to be switched off, otherwise, the acrylic sheet will break at the surface. Saw at 40% of the maximum cutting speed and do not force the saw. Let the saw run smoothly through the material, the saw must do the work. For more information about cutting acrylic, you can also read our article on this subject only.
Finishing off the cut edge
The saw marks left behind after cutting are called kerf marks: before finishing these marks, the deepest grooves must be sanded away. Start with grain 80, sand the edges nice and even and then repeat this with a finer grain, increasing from 80 to 200 to 800. More tips can be found in the article “Polishing acrylic“. If you also want to bend the acrylic sheet, you can read all about it in our article “Bending acrylic“.