Plexiglass is a transparent acrylic plastic that is an inexpensive alternative to glass, so at some point you be faced with the prospect of having to saw a piece of plexiglass to size, which can be troublesome. Plexiglass is prone to chipping and cracking when you cut into it
So… can you cut plexiglass with a table saw? Yes a table saw can be used to cut plexiglass and other acrylic materials to size, But you you need to make sure that you are using a blade that’s designed to cut plastic and you employ a proper technique.
A table saw is the easiest way to cut through a sheet of plexiglass or other acrylic materials, it has its drawbacks as well, since plexiglass is a thermoplastic, it needs some special handling.
A thermoplastic is a kind of plastic that can be melted down again and repurposed. It tends to melt under friction and the heat generated by a power saw is bound to melt plexiglass.
This is why you have to choose the blade you’re going to use with care and you also need to saw with care.
Plexiglass is popular to use in the place of glass as it does not shatter or crack.
For this reason it’s also the ideal material to use for greenhouses – the plexiglass lets in the optimum amount of light that plants need, but is still a robust material that can withstand rough weather conditions.
Things you’ll need for Cutting Plexiglass with a table saw
Cutting plexiglass with a table saw will require a few extra supplies that you wouldn’t normally need if you were cutting wood.
The most important item is a special blade that’s designed to cut through plastic materials.
Bare in mind not all acrylic sheets are the same, so you need to make sure that what you intend to cut is plexiglass, as some acrylic sheet’s can’t be cut on a table saw without significant melting.
There are three types of acrylic sheets:
- Cast acrylic
- Extruded acrylic
- Polycarbonate acrylic
Cast acrylic sheets these are what most people think of when they think of plexiglass. They are hard and can usually be cut with a table saw without melting providing the right saw blade is used. You’ll find the cast acrylics tend to cost a significant amount more than others.
Extruded acrylic sheets are another type of acrylic these tend to be softer and have much lower melting temperatures and as such these shouldn’t be cut with power tools at all. This type of sheeting is best brought down to size via the score and snap method. The benefit of extruded acrylic sheets is that they can be molded using heat.
Polycarbonate acrylic sheets are another type of plastic sheeting that you can buy. Polycarbonate sheets can be cut with power tools such as your table saw as long as you take some extra care. They are softer than plexiglass and may require some experimentation before you get the hang of which blade and how quickly you feed your sheets through your table saw.
The long and short of it is, make sure you know what you are about to cut is plexiglass before you run it through your table saw.
Plexiglass Strength
When you purchase plexiglass you may be looking for strength, there are many alternatives to plexiglass, but you will want to ensure you use the real plexiglass brand.
Here are some results of impact resistance tests done on the Plexiglas brand plexiglass compared to other types of glass.
| Product | Nominal Thickness (in) | Weight of free-falling steel ball (lb.) | F50 Energy to Break Product |
| Plexiglas Sheet | .098 | .25 | 3.0 |
| Plexiglas Sheer | .236 | 5 | 18.1 |
| Window Glass, single strength | .1 | .25 | .8 |
| Plate Glass | .250 | .25 | 2.0 |
| Laminated Glass | .250 | .25 | 1.1 |
As you can see, plexiglass is far superior to glass when it comes to impact resistance.
It took a five-pound steel ball far more energy to break through the thickest plexiglass than it took for a quarter pound steel ball to break through a piece of glass that was thicker.
Basically Plexiglass rules, which is why it’s often used for modifying your router.
Cutting plexiglass with a table saw
While you can use any table saw to cut through plexiglass provided the right blade is installed, It’s recommended that you use a table saw with at least a 10-inch blade and a 2-horsepower motor.
You also want your blade to be running at approximately 3,450 RPM, if that’s not possible that’s ok.
Step 1 – Safety first
Always use safety glasses when you are working with your table saw, but this is more important when cutting plexiglass. Shards of plastic can shoot out from the saw blade directly at your face.
So wear your safety glasses!
Step 2 – Check the thickness of the plexiglass
Measure the thickness of your chosen plexiglass with a tape measure. Only plexiglass that is ¼” thick or thicker should be cut with a table saw.
Anything thinner will chip badly or simply melt because of the friction caused by the saw.
Step 3 – Choose the correct saw blade
Make sure the blade is sharp and clean.
Some woodwork enthusiasts recommend using blades with 50 to 60 teeth. More teeth than this mean more friction and heat which might melt the plastic.
Personally I find the best blades for cutting plastic have between 60-80 evenly spaced carbide tipped teeth this will depend on the diameter of your blade. But the blade should have no rake and should have uniform teeth.
A blade with fewer teeth is also recommend for the softer varieties of plexiglass to prevent burning or melting.
The opposite goes for harder plexiglass, which needs a blade with more teeth to prevent chipping. A carbide-tipped blade is best. Ensure that it is perfectly parallel to the fence.
There are blades which have been specifically designed for cutting plastic, but it all depends on the type of plastic you are trying to cut, so the results from your blade will vary.
Step 4 – Measure the cut you want to make
Measure the size of the cut you wish to make and mark it on the plexiglass.
Note: Keep the width of the saw into account when you are setting the fence to hold the plastic in place as it will take up a tiny amount of space, which could cause your measurements to be slightly off.
Step 5 – Use a push block
Use a push block to hold the plexiglass and push it through the blade. This safety device is a must for any table saw work. It helps you to safely move the plastic sheet through the blade while keeping it flat against the fence.
The push block provides 3-directional force that keeps the material you work with safely in place on both sides of the blade to keep it from vibrating.
The push block provides a downwards force that keeps the plastic in place, a force from the side to keep it against the fence and a forward force to keep it moving forward.
This is important because uncontrolled vibration can lead to rough edges which you want to avoid.
You don’t have to buy a commercial push block. They are quite simple to make and you can find many videos on YouTube on how to go about it. It’s worth investing time or money into getting a push block if you want to keep all your fingers.
Step 6 – Make the cut – Technique for cutting Plexiglass with a table saw
The general process of cutting plexiglass is very similar to cutting wood, though there are some small details to consider to ensure the quality of the finished product and to keep yourself safe.
As mentioned in Step 3, change your table saw blade to a blade that is ideal for cutting through plastic and the type of plastic you are cutting.
Set the height of your blade so it’s only a half inch higher than the piece of acrylic sheeting you are going to cut.
Make sure you’ve followed Step 4 and measured and marked the sheet for your cuts.
Do not remove the protective field on the plexiglass, this will help prevent it from getting scratched.
Place the plexiglass onto your table saws infeed table with the protective film side down against the table saw table, then setup the table saw as you would for cutting wood, i.e. get your fence positioned and your workpiece tight against your fence.
SAFETY GLASSES ON!
Turn on the saw and push the plexiglass through the saw using a slow and smooth movement. If you use force or move the plastic too fast you will cause the edge to chip.
The push block and fence will ensure that the cut is perfect and that all your digits stay where they belong.
Be sure to hold the plexiglass firmly against the fence during the entire cutting process.
If you see that the edges are getting chipped, change the blade to one with more teeth; if the plastic melts, change the blade to one with fewer teeth and slow down as you push the plastic through the saw.
To save time, you can saw a few plexiglass sheets at the same time by stacking them on top of each other. Use clamps to keep the sheets from shifting.
Feed Rate
To be clear about how quickly you want to move your sheet through your table saw blade.
The recommended feed rate should be about 3 inches per second and you should move at a steady pace. You don’t have to be exact in this but as mentioned above slow and steady, if the sheet is on the thinner then you may want to reduce the feed rate.
Apply Pressure
As mentioned above you want your acrylic sheet to be held tightly against your fence, applying even pressure as you push it forward.
This is even more important if you are cutting a thin acrylic sheet as these tend to have a tendency to vibrate which can be dangerous.
Cross Cutting
You aren’t going to have a great time cross cutting acrylic sheets.
This is because they tend to chip at the corners. It can sometimes be helpful to start at one end, then flip the acrylic sheet and finish the cut coming from the other side.
Step 7 – Sand the edges – How to sand Acrylic
After you’ve made your cuts, the edges will likely be rough, they may even be slightly glazed from the heat of your table saw blade.
The only way to fix this is to sand the edge and here’s how I do it.
- Use a fine grit waterproof sandpaper with a sanding block, you want start with 120-180 grit
- Start with the coarse grit sandpaper and transition to the finer grit sandpaper as the plexiglass gets smoother and smoother.
- You will want your final sandpaper grit to be in the region of 600-grit sandpaper, this will provide a very smooth finish
- If you want an incredibly smooth finish you can attach a buffing pad to an electric drill and use that to buff the sanded edges.
Note: You cannot glue a polished acrylic edge, if you need/plan to glue the edge, then do not create a polished edge.
Other ways of cutting Plexiglass
Cutting plexiglass on a table saw is a fantastic option, but it can be overkill for what you are doing and in some cases the acrylic sheet is too thin or it’s of a type that can’t handle the heat of the blade.
Generally thinner pieces of plexiglass should be cut using other methods, this is mostly for safety as thin pieces of plexiglass have been known to be prone to kickback on a table saw, and kickback is never fun.
Here are some alternative ways of cutting your plexiglass without your table saw.
Plexiglass knife or Utility knife
This is the best method when dealing with thing pieces of plexiglass up to around an eighth of an inch. Use the knife to score the plexiglass along a straightedge.
Make eight to ten passes with the knife to ensure a good score line, then you can snap the plexiglass along the score line. I tend to put a dowel underneath just before the score line to assist in snapping.
If you’ve worked with plasterboard, this is the same method of scoring and snapping.
Dremel grinder with a cutting wheel
If you need to make an irregular cut (i.e. not straight) in your plexiglass sheet, a Dremel grinder with a cutting wheel can cut through thin pieces of plexiglass with ease.
Jigsaw
You can use a jigsaw on any thickness of plexiglass, the bonus is you can make straight, circles, or any irregular shaped cuts.
Circular Saw
Wait…. why use a circular saw if I have a table saw?
Well it’s true that a circular saw is very much like a table saw, so the blade choice is important, you need a blade that’s meant for cutting plexiglass.
The upside to a circular saw is portability when it comes to breaking down a plexiglass sheet.
