Drilling holes in acrylic requires the use of a drill bit specially designed for use with plastics. Standard metal drill bits will work, but without extensive modification, the metal drill bit will crack and chip the brittle acrylic sheet. There are precautions that you must take to ensure that the hole does not get hot and melt the acrylic sheet or that the exit side of the acrylic sheet does not crack. Taking extra precautions will ensure that the you will have a perfectly drilled hole in the acrylic sheet.
Things You'll Need
1x4-inch piece of wood longer than the acrylic sheet
Two pair of self-locking pliers
Drill bit designed for plastic
Spray bottle filled with water
Countersink drill bit
Lay the 3/8-inch plywood on a firm flat surface that allows you to work easily and place the acrylic sheet on top of the plywood.
Place the 1x4-inch piece of wood across the acrylic sheet and secure the plank to the top of the acrylic sheet by clamping one pair of self-locking pliers to each side of the acrylic sheet.
Put on your safety glasses and secure the drill bit into the chuck of the drill motor.
Align the tip of the drill bit with the location that you need to drill the hole through the acrylic sheet. Depress the trigger of the drill motor to start drilling the hole into the acrylic sheet.
Spray water on the drill bit with the water bottle to keep the drill bit cool and provide a smooth finish to the drilled hole.
Drill through the acrylic sheet and into the 3/8-inch plywood. Reverse the direction of the drill motor to remove the drill bit from the acrylic sheet.
Release the self-locking pliers, remove the 1x4-inch plank from the top of the acrylic sheet and exchange the drill bit for the countersink bit.
Lightly hit both sides of the hole you drilled into the acrylic sheet with the countersink bit to remove the bur from the acrylic sheet. If the bur is not removed, the acrylic sheet can crack when pressure is applied to the sheet with a fastener.