Plexiglass is the commercial name for poly methyl methacrylate. Plexiglass being transparent appears just like a glass, but is indeed a plastic. A plexiglass sheet offers the same transparency as glass but without the glare. It is being valued in various industries as it carries higher strength, is more durable, has lower weight and is shatter resistant. There are wide ranging applications of plexiglass and its use is highly preferred in the making windows, helmets, aquariums and car lights.
However, for using plexiglass panels these would need to be drilled so that they can be screwed to fit. But drilling a plexiglass panel is not as simple as it requires special tools and techniques.
Why drilling plexiglass sheet is not as easy?
Plexiglass is prone to cracks and chipping while drilling hence it is essential that proper technique and right tools are employed for the purpose.
Use a specially designed drilling bit
Drilling a plexiglass sheet requires specially designed bits which have a different tip angle. A standard drill bit is spiral and it may not give the type of finishing that you would desire. Besides it works quite aggressively and hence the sheet is prone to crack
Using the right drilling technique is equally important
Once you have the right drilling bit the next important task would be to use the right technique. A right technique is one that would help you drill flawlessly without causing any damage to the sheet or putting the health and safety of the driller at risk.
Let’s understand the right technique of drilling a plexiglass.
Ensure safety of the driller
First thing that you should do before beginning to drill a hole is to wear a safety glass to protect your eyes from acrylic chip that would fly during the drilling process.
Get some drilling practice to fine tune your skills
It is advisable to do some practice on a scrap plexiglass sheets before you actually take up the job. This will help you get a grasp on the nitty-gritty of drilling a plexiglass sheet. After a thorough practice, once you are prepared to handle the task professionally, you may take the plexiglass sheet on which you need to drill the holes.
Use a back support for the acrylic sheet to be drilled
Place the plexiglass sheet on a medium density fibre board. This is essential to ensure that the bottom of the acrylic or plexiglass sheet does not blow out. An MDF sheet would allow the bit to continue into a solid surface, as it reaches the bottom of the plexiglass sheet. Alternatively, lowering the feed rate of the drilling machine when it is close to the bottom would also prevent chipping or blowing off the bottom surface.
The right drill speed
The rotational speed of the drill machine has to be adjusted according to feed rate, depth of the hole to be drilled and the finishing required. Rule of the thumb is to lower the speed if you notice melting of the sheet. The same applies if there is whitening of the sheet. Melting or whitening generally occurs when the hole to be drilled is deep. In case of shallow holes, there is a greater chance of chipping.
Hence while drilling a deep hole or a stack of plexiglass sheets at a time it is advisable to use water as a coolant. Water will avoid the build-up of heat and also help in drilling a smooth hole. As an alternative, you may also opt to provide for a supply of continuous air stream which as well will keep the heat away and avoid melting.
Peck drilling for thick sheets
You may opt for peck drilling (retracting the drill machine periodically) while drilling thick sheets. Peck drilling can avoid melting as it allows the sheet to cool down and you can also clear the chips during the drilling process.
To ensure flawless drilling of plexiglass sheets it is best to refer to the users guide provided by the acrylic manufacturer. The guide will provide very clear instructions on the type of drill bit to be used, the feed rate and other precautions to be taken while drilling.