If you are working with plastic, specifically high-density polyethylene, otherwise known as HDPE, chances are pretty big that you will need to cut it down to size or shape it to suit your needs.
Well, this thermoplastic polymer is quite tough, yet also surprisingly easy to work with. So, what tools can you use to cut HDPE, and what is the best tool to do so? Let’s figure out how to cut high-density polyethylene.
6 Best Ways to Cut HDPE
As mentioned above, high-density polyethylene is not very hard to work with, and for the most part, most of the tools and blades that you would use to cut solid lumber or plywood will work just fine for HDPE. Let’s take a look at the seven best tools for this job.
1. Using a Table Saw
If you need to cut large sheets of high-density polyethylene down to size, one of the best tools to use is a table saw. When using this tool, you want to ensure that you have a very sharp blade, preferably a carbide blade, and you want it to be in good condition.
To avoid rough edges, you also may want to use a reverse or negative rake blade. A Table saw is also a good option if you need to make a bevel cut, as the blades can usually bevel to both sides. Keep the speed of the saw as slow as possible to avoid melting the high-density polyethylene, as extreme heat can cause it to melt.
2. Using a Circular Saw
If you need to make straight cuts into HDPE, such as for cutting one large piece into two halves, then a circular saw is one of the best tools at your disposal. This tool is ideal for cutting straight lines, and as long as you have support from underneath, you can use a circular saw to cut some fairly large sheets of HDPE.
That said, a circular saw is best if you are on the go and need a portable tool for cutting small to medium or medium-large sheets of HDPE.
Keep in mind that this tool will also allow you to make bevel cuts. Like with a table saw, you’ll want to use a negative rake blade that is very new and sharp, preferably a carbide blade. You also want to keep the speed of the saw as slow as possible to avoid melting the material.
3. Using a Miter Saw
The next best option that you have at your disposal if you are cutting small to medium size sheets of high-density polyethylene is the miter saw. This saw is relatively portable and able to make very precise straight cuts, particularly when it comes to making so-called cross cuts, although it doesn’t really have enough space to make rip or length cuts.
That said, if you need to make bevel and/or miter cuts, then this tool is best. Just like with the previous tools, make sure to use a carbide-tipped negative rake blade that is very sharp, and make sure to use the saw on the lowest speed setting possible.
4. Using a Jigsaw
If you need to make curved cuts or you want to cut circles and irregular shapes, then using a jigsaw will work just fine. Now, while this tool can also be used to make straight cuts, it won’t work as well for this purpose because keeping the blade aligned and moving in a straight line through high-density polyethylene can be difficult.
Moreover, when using a jigsaw, you will want to use a 14 TPI wood cutting blade, and you want to use it on the lowest speed setting possible. As with all of the other methods, you want to avoid melting the material with too much speed.
5. Using a Router
If you are working with very small pieces of HDPE, and you need to cut them apart into even smaller pieces, cut short straight lines, or cut some shapes and irregular curves, then a router affixed with a very sharp cutting disc designed for wood cutting will do just fine.
Just keep in mind that you will require a good bit of accuracy and precision if you expect the result to be good.
This is not a tool that you will want to use to cut through thick sheets of high-density polyethylene either, as it’s really only ideal for cutting thinner pieces of this material. You may also use it to score some lines and patterns into the surface of the polymer.
6. Using a Reciprocating Saw
If the name of the game is demolition, and you just need to break down and cut apart some high-density polyethylene to get rid of it, then a good reciprocating saw or Sawzall will do the trick.
Of course, here you aren’t looking for straight or clean cuts, so the type of blade you use isn’t too important. This tool is simply for destroying material to clear it out. That said, if you are in a pinch, you may also use this tool to cut high-density polyethylene pipes for plumbing purposes.
How to Cut High-Density Polyethylene
Now that you know what tools to use to cut high-density polyethylene, let’s go through a quick tutorial on the matter. Here, we will be focusing on using a table saw to cut HDPE.
Step 1: Measure and Mark
First, you need to measure the cut that you plan on making. You then want to use a ruler or any other straight edge, as well as a carpenter’s pencil or washable marker to mark the line. Always measure twice and cut once!
Step 2: Prepare the Saw and Yourself
You now want to set the fence on the table saw to the right depth, according to the cut you measured in the first step. With the fence aligned, you then want to set the blade so that it protrudes about ½” past the height of the high-density polyethylene sheet. Also, make sure that you are using a negative rake carbide blade. You now also want to prepare a spray bottle with some water, and then put on your safety glasses.
Step 3: Make the Cut
Spray the surface of the material with some water to keep it wet, so it stays lubricated and doesn’t melt. Put the sheet on the table of the table saw, start the saw up, and get the blade moving, then pass the high-density polyethylene sheet through the blade just like you would with a piece of wood.
Step 4: Sand the Edges
You might have some rough edges left, so use some 120-grit sandpaper to smooth everything out.
Mistakes to Avoid, Tips & Tricks
Let’s go over a few tips to help make this process as easy and safe as possible:
- Keep spraying water as you make the cut, as this will help avoid having the high-density polyethylene melt
- If making straight cuts, either a table or circular saw will work best
- Whatever saw is being used, make sure to keep it slow, as this will help keep the material from melting
Summary
Now that you know how to cut high-density polyethylene, you can choose the method that works best for you.