Acrylic is something that has been around for longer than you might think. All kinds of things can be made out of acrylic, including pens, handles, and pieces of jewelry.
Simply put, yes, you can turn acrylic on a wood lathe. However, there are certain tricks to doing so and specific precautions that you should take. You should never assume that just because you can use a wood lathe for acrylic working with it will be the same as working with wood.
What Is Acrylic?
The word ‘acrylic’ is actually a very broad term since acrylic is made in a number of different ways. The most common compounds that are used to make acrylic are polymethyl methacrylate (PMMA) and polymethyl 2-methyl propenoate. These are a form of clear plastic or, more specifically, thermoplastic.
Various acrylic mixes are used for a lot of things, from aquariums to visors and even as something that is used in implants and to replace bone. Acrylic can be very durable, and it is extremely versatile. The fact that in its natural state acrylic is clear makes it easy to color in any way imaginable, including in ways that it is impossible to color wood.
With cheap acrylics, you generally get what you pay for. These are often very brittle, cracking easily and breaking more often even after they have been completed, not to mention having a much more noticeable stink to them.
Where Do You Get It?
There are many different sites and companies that sell acrylic. Price ranges can vary considerably depending on the quality of acrylic/resin that you are looking to get.
Something else that may impact the cost of blanks is the color of the acrylic. My go to source for these blanks is Rockler. I’ve had really good success with this particular brand (Rockler link).
Then, there is also the option to buy custom made acrylic blanks from someone who is experienced at making them. These can be a bit more expensive but are sometimes well worth the price. Some of these blanks can be truly unique. BogandBrass is one of my favorite sellers on Etsy and offer a wide variety of blanks. You can find their store by clicking here.
It is possible to cast your own blanks too if you have the chemicals and everything that you need. This can give you a ton more opportunities to make a unique piece of acrylic. Since the resin is clear, during the stage before it hardens you can put anything you want into it.
This includes everything from small seashells to wood shavings as well as the coloring. Then, when it is hardened, you can use the lathe to make anything that you want out of it. Your imagination is the limit when you are making your own acrylic.
If you are interested in making your own blanks, the video below will take you through the process.
How Turning Acrylic Is Different From Turning Wood
There are a number of differences between turning wood and turning acrylic. For starters, the feel of them is completely different from each other, and the finished result looks just as different as well. All in all, wood is slightly easier to work with, but acrylic is just as satisfying.
Before you get started, you should take a look at what kind of acrylic you have. There are two different kinds of acrylic: extruded and cast. The cast kind is easier to work with and is not as likely to melt and so, if you are starting out, you will likely want to go with this option.
If you can’t find out which type you have, cut a small piece of your blank off with a band saw or something similar. Then, look at the spot where you made the cut. If there is any sign of melting, then you probably have extruded acrylic.
For a more in-depth look with tips on woodturning with resin, take a look at this article I wrote.
Besides the handling, you should be forewarned that acrylic has a definite smell to it which is far from pleasant and prone to lingering. While this smell is the most prominent when you are drilling and turning it, it is also present to a smaller extent when you sand it too.
If part of your preparations involves needing to drill in your acrylic, take it nice and slow. I’d highly suggest using a specialized drill bit that is made for acrylic. This will help the process go much smoother. I picked up this set made by FTM and have been very happy with them (Amazon link). The bits have lasted a long time and done really well.
To get rid of the corners and start prepping your blank for something more rounded, do not use a roughing gouge like you do on wood. Instead, use a belt sander or something else that will take off these edges more gently. When you are first getting it into a more rounded shape, acrylic can crack, making it look like a piece of shattered glass. While this can be a neat effect, it is not good to work with.
Turning is, of course, different from beginning to end as compared to wood. You’ll see in this paragraph, turning acrylic is certainly a muti-layered balancing act. When you are turning the acrylic, there are two main things that you should be careful about.
The first is that you do not want the piece of acrylic you are working on to overheat. It’s important to make sure the blank nor your your lathe get too hot so it doesn’t melt your work. The best advice, is to turn a low speed and allow your piece to cool as needed.
The second common problem when turning acrylic is that the acrylic is prone to cracking even if it is prepped correctly. This is in part because acrylic is harder than wood. To keep your piece from cracking, make sure the tools you are using a sharpened. This will significantly reduce the risk of any problems.
Another key difference in turning acrylic instead of wood is the waste. When turning wood, the shavings will generally fall into a pile on the floor. Expect the opposite with acrylic. It tends to wrap itself around the blank you are cutting it from and your tools. You’ll likely need to stop your machine from time to time to clear away the mess.
When it comes to the right turning speed, things get a little more complicated. Some feel that it is alright to turn at the same speed as wood, while others think that turning acrylic slower is better.
It is true that turning slower does make for less heat, making your piece of acrylic less likely to melt. However, going to slow can make your turning seem slow, tedious, and frustrating. If you are new to working with acrylic, try going a little slower than your usual speed until you get a feel for it.
Keep in mind that acrylic is harder than wood, so you will have to press harder on your lathe. This is a bit of a balancing act since you do not want to cause too much friction and melt your acrylic.
The finishing, like the rest of the process, is completely different for acrylic than it is for wood. Firstly, you need to wet sand acrylic since dry sanding does not work as it does with wood. Take it easy on the sanding. This step in the process can also cause melting to occur if you get too aggressive.
You can use your lathe for the sanding, but it is best to do as much of this by hand as possible and then to simply finish the last few touches with the lath on a low speed. Polishing acrylic is best done with a micromesh (Like this one) or with a kit that you can get which is specifically designed for finishing acrylic.
For sandpaper, you can use anything from about 180 grit on up to around 1500 grit.
While it is true that acrylic can stink when you are working with it, this can be counterbalanced when you get to the point of applying your finish. Acrylic and wood require completely different finishes, and you should always get a finish that is specifically for acrylics.
You can use your lathe to apply the finish along with a rag. Just be careful about overheating and do not apply pressure.
Many people do both acrylic and wood on their wood lathe. While wood certainly has a classic look, acrylic has more color to it. True, wood can be dyed, and some exotic woods are quite brightly colored as well. However, acrylic does have more vibrancy most of the time.
All in all, people tend to love color. While some clients like the look of wood, it often takes someone who knows and loves wood to truly appreciate the finer points in wood. Segmented woods and woods that have burls or spalting in them can be true works of art, but they are more expensive.
If you are making something like a pen with acrylic, you should always keep in mind the slight transparency acrylic has even when it is colored. This means that the internal brass tube of the pen will show through some no matter how deeply the acrylic is colored.
You can either get an inner tube made of chrome or paint your tube white or some other color to either match or contrast the acrylic color. While this is true for pens, it is something that you should think about no matter what you are doing with the acrylic if something is to be inside it.