3D printing allows us to make some incredible things in our homes and workshops. People are prototyping products, designing bits and pieces to make their lives better, and spitting out more amusing trinkets than ever before.

Unfortunately, for the bulk of us who have a typical filament based printer, we’re stuck with a common problem. The surface finish of even the nicest prints are covered in tiny ridges. This is simply due to the way the printer works, building layer by layer on top of each other.

The great thing about the 3D printing community is that, for the most part, everyone loves to share the methods and practices they used to achieve things. Surface finishing is no different.

Some time ago I saw a method for smoothing out prints that involved making a chamber to hold acetone, placing your print in the chamber, then heating everything up for a short period of time. Typically people were using the heated beds of their printers to do this. I tried it and it worked decently. However, this really seemed like an incredibly dangerous setup. Not only do you have the enclosed space of your workshop, you have a container of acetone that is being heated up, building up pressure. Not a good situation.

Since then, several people have realized that the heating aspect is unnecessary. This allows us to do acetone smoothing in a much safer fashion.

It should be noted that this process only works on ABS.

To build a smoothing chamber, you don’t need much.

– a container, not too large

– paper towels

– aluminum foil

– acetone

As you can see in the video, the paper towels serve to hold acetone and distribute it more evenly. The foil simply keeps your part from coming in direct contact with the acetone.

Timing will vary depending on the size of your container, the size of your part, and how much acetone you add. This will require trial and error, so it may be smart to print a few copies of a test piece to figure out what works for you.

It should be pointed out that the ridges on your model will still be visible to varying degrees, even after acetone smoothing. The head that I left in the chamber for the longest time is completely smooth to the touch on the vertical surfaces but you can still see the remnants of the layers. Sloping surfaces like the top of the head are still clearly visible.

My personal feelings about the finish are that it generally looks a little to melted for my tastes. I’ve seen a few situations where it was preferred, but most of the time I’m fine with the ridges. However, I wanted to learn this and get the process down because you never know when you’ll need it. I like having this “tool” in my toolbox of skills.