Are you tired of seeing cracked and chipped plexiglass in your DIY projects? You’re not alone.
Though popular, durable and versatile, drilling plexiglass is tricky. The good news is that you can learn how to drill plexiglass like a pro with a few simple steps and some expert tips.
In this article, I’ll guide you through the process of drilling plexiglass and share some insider secrets that will help you achieve flawless results.
So, whether you’re a seasoned DIY enthusiast or just starting out, get ready to elevate your plexiglass game with my essential guide.
How to Drill Plexiglass Without Cracking
To drill plexiglass without cracking it, use a plastic-specific drill bit or a special spiral drill bit. Secure the plexiglass in place, mark the spot the begin drilling. Drill slowly and steadily with gentle pressure, and keep the plexiglass cool with water or lubricant. Do not apply too much force as this can cause the material to crack.
What Is Plexiglass?
Plexiglass is a lightweight, transparent plastic made from an acrylic resin or polymethyl methacrylate (PMMA).
Originally known as Perspex or Lucite, plexiglass was developed in the early 20th century as a shatter-resistant alternative to traditional glass.
Plexiglass is made by polymerizing methyl methacrylate monomer through free-radical polymerization. The resulting material is lightweight, strong, and transparent, with a high level of light transmission.
Due to its high strength, plexiglass was used in military applications such as submarine periscopes and aircraft windows.
Over time, it has become popular for commercial and industrial applications.
Today, plexiglass is used in the automotive industry. It’s used in headlight covers, windscreens, and in construction, for skylights, windows, and safety barriers.
It’s also used in making illuminated signs and displays, and in the medical industry, for medical devices and dental implants.
Plexiglass has also become popular for DIY projects, including home decor, jewelry, and furniture.
Can You Drill Through Plexiglass?
Yes, you can drill through plexiglass. However, you require special precautions and techniques to avoid cracking or damaging the material.
Use low pressure when drilling because too much pressure or speed can cause the plexiglass to crack or chip.
You’ll also need a drill bit specifically designed for plastics, such as a carbide-tipped or diamond-tipped bit.
Clamping the plexiglass securely to a work surface is also good to prevent it from moving around during the drilling process.
How to Drill Holes in Acrylic Without Cracking
Drilling acrylic sheets requires special techniques to prevent cracking or damaging the material.
To start, choose a drill bit designed for plastics, such as a carbide-tipped or diamond-tipped bit.
These bits have sharper edges and generate less heat, reducing the risk of cracking the acrylic. Next, clamp the acrylic sheet securely to a work surface, away from where you plan to drill the hole.
Use a pencil or marker to mark the location where you want the hole. Start with a small pilot hole to prevent the larger drill bit from slipping or wandering.
Using low speed and light pressure to keep the bit cutting when drilling. Avoid stopping and starting the drill, as this can create heat and increase the risk of cracking.
To prevent the acrylic from cracking when the drill bit breaks through the other side, place a piece of scrap wood or plastic behind the sheet as a backer board.
Finally, clean the edges of the hole with a scraper or sandpaper.
Interesting Read: Why is My Acrylic Paint Cracking?
How To Drill Plexiglass Without Cracking
Materials Needed to Drill Plexiglass Without Cracking:
- Plexiglass sheet
- Variable speed drill
- Drill bits (preferably designed for plastics)
- Masking tape or painter’s tape
- Lubricant or soapy water
- Scrap wood or backing material
- Safety goggles
- Dust mask
- Clean, soft cloth or rag.
Now let’s get into the techniques for drilling plexiglas without cracking.
Step 1: Select the tools you want to use
When it comes to drilling plexiglass, you need to take safety precautions. One of the most important safety precautions is to wear safety goggles and gloves.
This will protect your hands and eyes from any acrylic chips fly.
Choose a drill bit that is specifically designed for drilling into the plexiglass. These are made of carbide or diamond and are found at most home improvement stores.
Also, select an appropriate drill speed based on the material you are using.
Faster speeds work better with harder plastics, while slower ones work better with softer plastics.
Step 2: Mark where you want to drill
Use a grease pencil or other marking tool to draw a line where you want to drill. This will help keep you from drifting off course and damaging the plexiglass.
Step 3: Set the drill
To get started, ensure that your corded drill is plugged into a power outlet. If you have a cordless drill, insert a fully charged battery.
Then, set the rotational speed to slower to achieve greater precision when drilling. As a general guideline, lower the speed if you need to drill a larger hole.
When selecting a drill, choose the right diameter to prevent cracking. Plexiglass may expand or contract with changes in temperature.
To avoid this, drill a hole slightly larger than the bolt diameter or screw you plan to insert. Failing to do so could cause the material to break if it contracts.
Step 4: Place the plexiglass plate on a flat surface
To reduce the risk of cracking, place a piece of scrap wood or plywood underneath the plexiglass plate.
This will provide additional support and help keep the drill from slipping and causing damage to the material.
Step 5: Aligning drill bit and drilling holes
Align the drill bit with the mark you made on the plexiglass then drill slowly but steadily.
Apply very little pressure, and don’t stop and start the drill as this can generate heat and cause the material to crack.
As you drill, you may notice small shavings forming around the hole. Don’t worry, this is normal.
Step 6: Airing and cooling
Once you’ve drilled the hole, let the plexiglass cool for a few minutes before removing it from the work surface. This will help prevent any residual heat from causing the material to crack.
You can use a handheld air blower or compressed air to cool down the material quickly. Use a countersink cutter to finish the hole.
Why Does Plexiglass Crack When Drilling?
Plexiglass can crack when drilling due to several factors.
Some of the reasons are: using the wrong type of drill bit, too much speed and pressure applied during drilling, and lack of proper support for the material.
When using a regular drill bit designed for metal or wood, the sharpness and angle of the bit can cause the material to crack or shatter when drilling.
This is because the force applied to the material during drilling generates heat that softens the plexiglass, making it more susceptible to cracking.
How to Prevent Plexiglass from Cracking when Drilling?
Here are some tips to prevent plexiglass from cracking when drilling:
1. Use a drill bit designed for drilling plastics, such as a carbide-tipped or diamond-tipped bit. Avoid using standard metal or wood bits, as they can generate too much heat and cause the plexiglass to crack.
2. Before you start drilling, use a pencil or marker to mark the location where you want to drill the hole. This will help ensure that your hole is in the right spot and that you don’t have to re-drill, which can cause the plexiglass to crack.
3. Clamp the plexiglass securely to a work surface to prevent it from moving or vibrating while you drill. This will help ensure that you drill in the right spot and that you don’t crack it.
4. Set the drill to a low speed and apply steady, even pressure as you drill. Avoid stopping and starting the drill, as this can generate heat and cause the plexiglass to crack.
5. After drilling, allow the plexiglass to cool for a few minutes before removing it from the work surface. This will help prevent any residual heat from causing the material to crack.
6. Apply a small amount of water or oil to the drill bit before drilling to reduce friction and prevent the plexiglass from overheating. This will help minimize the risk of cracking.
7. Start with a pilot hole: If you need to drill a larger hole, start by making a small pilot hole first. This will help guide the drill and prevent the plexiglass from cracking.
8. Place a piece of scrap wood or plastic underneath the plexiglass to provide support and prevent it from cracking as you drill. This is especially useful when drilling near the edge of the material.
9. Clean up excess material: After drilling, remove any leftover bits of plexiglass or debris from the hole. This will help prevent cracking or chipping when you insert bolts or screws.
Interesting read: Can you trim acrylic nails?
How Do You Choose A Drill Bit?
When choosing a drill bit for drilling plexiglass, there are several factors to consider:
1. Size: Choose a drill bit size that matches the diameter of the hole you need to drill. Choose a bit that is slightly larger than the diameter of the screw or bolt that you’ll be using. This will prevent the plexiglass from cracking due to expansion or contraction caused by temperature changes.
2. Type of hole: Determine what type of hole you need to drill. If you’re drilling a simple through-hole, a standard twist drill bit will suffice. However, if you’re drilling a countersunk or counterbored hole, you’ll need a specialized bit designed for that purpose.
3. Speed: Select a drill bit with a low-speed rating. This will help prevent the plexiglass from overheating and cracking due to the friction caused by the high speed of the drill.
Types of Drill Bits to Avoid Cracking in Plexiglass
Standard twist drill bits
Standard twist drill bits have a cylindrical shape with a spiral flute design that helps to remove material from the hole being drilled.
One of the main advantages of standard twist drill bits is their availability and affordability. They are used for drilling different materials and come in a variety of sizes.
However, they are more prone to chipping and cracking plexiglass than plastic drill bits or step drill bits.
When using standard twist drill bits to drill plexiglass, use a slow speed and light pressure to reduce the risk of cracking or chipping the material.
Plastic drill bits
Plastic drill bits are designed to drill through plastic materials without cracking or damaging them. These bits have a sharper point and are made from materials like high-speed steel, cobalt, or carbide.
Plastic drill bits reduce the risk of cracking or chipping the plexiglass during drilling. They also produce clean and precise holes with a smooth finish.
Another benefit is that they generate less heat than other types of drill bits. This is important when drilling plexiglass as it can melt or deform due to high heat.
Use plastic drill bits at a slower speed than other types of bits. I recommend between 1000 and 2000 RPM.
Step drill bits
Step drill bits, also known as cone drill bits or unibits, are another type of drill bit used for plexiglass and other plastic materials.
They have a conical shape with multiple steps. Each step increases in size, allowing them to drill holes of different diameters in a single operation.
One of the advantages of step drill bits is that they can produce clean and accurate holes with minimal chipping or cracking of the plexiglass.
They are also very versatile and used for a wide range of materials, including metal, wood, and plastic.
Cone drill bit
A cone drill bit has a conical shape with multiple steps or levels of increasing diameter. The design of cone drill bits allows them to drill multiple hole sizes in a single operation.
This makes them useful for drilling plexiglass and other plastic materials.
If the bit becomes too hot, it can melt the plexiglass, which can cause the material to warp, crack or shatter.
Milling drill bits
Milling drill bits have multiple flutes or cutting edges along the length of the bit, allowing for precise cuts and smoother finishes.
Milling drill bits come in a variety of shapes and sizes, each designed for specific cutting applications.
Some types of milling drill bits, such as straight-flute bits, are ideal for drilling plexiglass because they produce a clean, precise cut with minimal chipping or cracking.
Other types, such as ball-nose or tapered bits, are better suited for more complex shaping and contouring.
Spade drill bits
Spade drill bits have a flat, paddle-shaped tip with a sharp point in the center and two cutting edges along the sides.
Though I do not recommend them for drilling plexiglass, you can use them in certain situations with caution.
Use a backing plate or sacrificial board underneath the plexiglass to prevent it from cracking or chipping.
Spiral drill bits
Spiral drill bits, also known as twist bits, are the most common type of drill bits. They feature a pointed tip and spiral flutes that are designed to remove material from the hole as the bit rotates.
When using a spiral drill bit to drill plexiglass, use a slow speed and low pressure to prevent cracking or chipping of the material.
Drill Machine for Drilling into Plexiglass
When it comes to drilling into plexiglass, choosing the right tools is essential. While handheld electric drills can work a suitable drill machine is the best.
Pillar drilling machine – This is a floor-standing drill press that provides a stable and accurate drilling platform. It has a fixed base, an adjustable table, and a drill head. This type of machine is ideal for drilling larger holes or multiple holes with consistent accuracy.
Drill press – This is a smaller, bench-top version of the pillar drilling machine. It has a similar design with a fixed base, an adjustable table, and a drill head that you can raise or lower. It is also an accurate and stable drilling platform but is better suited for smaller jobs.
Handheld electric drill – This is a portable and versatile option for drilling plexiglass. It allows for greater mobility and flexibility. But, you require a bit more skill and care to ensure the drill bit remains perpendicular to the surface of the material.
How to Repair Cracked Plexiglass?
You can repair a cracked piece of plexiglass in a few simple steps:
Step 1: Use a clean, soft cloth and a mild cleaner to remove any dirt or debris from the surface of the plexiglass around the crack. Allow it to dry completely before proceeding.
Step 2: Determine the size and location of the crack. If it is a small crack, less than 6 inches long, you can proceed with repairing it yourself.
Step 3: Apply a small amount of plexiglass adhesive to the crack and use a toothpick to spread it evenly along the length of the crack. Be careful not to apply too much pressure or the crack may widen.
Step 4: Follow the instructions on the adhesive to determine the drying time. Do not disturb the area while the adhesive is drying.
Step 5: Once the adhesive has dried, use fine-grit sandpaper to sand down any excess adhesive. Then, use a plastic polish to restore the shine and remove any remaining scratches.
Interesting Read: How to Prevent Acrylic Paint From Cracking on Shoes
What kind of drill bit is used for plexiglass?
Conical drill bits are the most suitable for drilling into plexiglass. They have a point and a special tip that prevents cracking and breaking of the material. They also generate less heat in comparison to standard drills, which makes them ideal for this delicate material.
What is the best way to drill through plexiglass?
The best way to drill through plexiglass is to use a special spiral bits drill and work slowly. Do not apply too much pressure as this may cause cracking or shattering of the material.
Can you drill a screw into plexiglass?
Yes, you can drill a screw into plexiglass. The key to successfully drilling a screw into plexiglass is to use the right type of drill bit and the correct amount of pressure. I recommend a carbide or diamond-tipped drill bit because it has the ability to cut through the tough surface of plexiglass.
Can you drill thin plexiglass?
Yes, you can drill thin plexiglass. When drilling plexiglass, use the correct bit and techniques for a successful project. For drilling thin plexiglass sheet (under 3/16 inch thick), use a high-speed steel bit with a 118-degree point angle.
Can you use a wood drill bit on plexiglass?
No, I do not recommend using a wood drill bit on plexiglass. Drilling wood requires bits that are designed specifically for softer materials like plywood, which could quickly break or shatter when used on plexiglass.
Do you drill plexiglass fast or slow?
The best way to drill plexiglass is at a slow and steady speed. When drilling plexiglass, use sharp and high-quality drill bits as well as special lubricants that won’t damage the surface of the material.
Final thoughts on how to drill holes in acrylic without cracking
Drilling plexiglass can seem daunting at first, but with the right tools and techniques, you can do it easily and without cracking.
By choosing the correct drill bit, adjusting the speed of your drill, and taking your time, you can achieve a precise and clean hole in your plexiglass.
Remember to take safety precautions, wear protective gear, and work in a well-ventilated area. Don’t be afraid to take on your next plexiglass project with confidence and precision.