ABS 3D Print Smoothing Explained

Whether you offer 3D printing as a service or if you simply enjoy 3D printing projects at home as a hobby, it’s important to understand print smoothing and the use of acetone in 3D print vapor smoothing.

Overview and Terminology

The abbreviation ABS stands for “Acrylonitrile butadiene styrene”. It is an industrial plastic that makes up the second most common printing material in 3D – behind PLA.

Acetone is used to smooth 3D prints made of ABS. Acetone dissolves ABS – if it is applied correctly, only the corners of the individual print layers dissolve. This results in a smooth surface. The best variant for smoothing ABS is an acetone steam bath (‘vapor smoothing’).

Vapor smoothing is a technique for improving the surface finish of 3d-printed parts. It uses acetone vapor to smooth the surfaces of ABS prints, removing the layer lines that result from the printing process.

Acetone is very flammable, so don’t use it near fire or something that can cause a spark. Also, be sure to work in a well-ventilated area since the vapor can cause headaches, dizziness, and a sore throat if breathed in too much. See full safety precautions here.

ABS Acetone Vapor Smoothing Simplified

Faster than sanding, Acetone vapor smoothing takes advantage of the fact that ABS melts very slightly when in contact with acetone fumes.

To create your own acetone vapor bath, you’ll need the following materials:

3D Print Vapor Smoothing Checklist

• A glass or metal container that is large enough to hold your print without touching the sides, bottom, or top.
• Strong kitchen roll
• A timer
• Something non-reactive to stand your print on, such as glass, metal, or aluminum foil.
• 100% pure acetone (not nail varnish remover)
• Safety equipment such as eye protection, nitrile gloves, and a well-ventilated area to work in.

Once you have all the materials, you just need to follow the steps below:

1. Place your non-reactive base in the bottom of your container.
2. Soak your strong kitchen roll in acetone and plaster it to the sides of the container so it surrounds where the print will sit.
3. Place your print in the container, on the base, without it touching the acetone-soaked kitchen roll.
4. Close and seal the container.
5. Leave your print for about 15 minutes. The acetone vapor should have caused the surface to become visibly smoother and shinier.
6. If this has happened, remove the print, being careful not to touch any of the details as the surface will be soft, and leave it to harden for at least an hour in a well-ventilated space.
7. If the print is still matte and rough, leave it in the container, checking every five minutes, until the desired result is achieved before removing it and leaving it to harden.

Once your print has hardened, it should be smooth, shiny, and stepping line-free.

Tips & Tricks – ABS/Acetone Vapor Smoothing

Here’s some tips and tricks that may help simplify your process of smoothing a 3D print and improve your 3D print quality.

Finding the Right Container

Glass is very suitable for the steam bath, but it is often not easy to find a glass bell with the right dimensions. Try using glass bell jar covers or similar items. Alternatively, a metal box can give a similarly good effect, but finding the right size is key.

Fan Increases Effectiveness

A nice feature for the container is a fan.

This is certainly not a must, but it can increase the effectiveness by improving air circulation. The fan should be attached to the underside of the lid so that the airflow is directly directed at the respective model.

Heating Pad Accelerates the Process

And one more optional feature, which can prove to be helpful. A heating pad will better saturate the air inside, speeding up the entire process. Alternatively, the container can also be placed on a warm surface – but this must not be hot under any circumstances! Only warm.

Metal Plate as an Ideal Base

The base is an important factor in the steam bath. The ABS 3D print must have a good base and it can find it through a metal plate, which can be placed on cardboard.

It is important that it has a few centimeters from the surface. As a basis for smoothed models, an old printer steel sheet is very suitable. So you can work well without touching the model.

Related Questions:

What role does acetone play in smoothing ABS 3D prints?

Acetone is normally used for cleaning purposes, but it is an ideal solvent for smoothing 3D prints. This is especially true for ABS printing, as ABS is very reactive to acetone and dissolves in it.

What are the methods for smoothing ABS 3D prints?

Three methods in particular are common. First, the acetone can be spread on the 3D print with a brush, but the result is often not smooth and glossy – and thus not satisfactory.

An acetone bath promises more success in some cases but has the problem that there is little control and the result can vary.

Therefore, the ideal method is vapor smoothing with an acetone steam bath, which is most likely to guarantee a smooth and shiny final product.

What do I have to consider when vapor smoothing ABS 3D prints?

The method requires good preparation, patience and a good strategy. However, the process itself is quite simple to implement. Before getting started, safety guidelines should definitely be established. The most important is that there are no open sources of ignition (flames or similar) – because acetone is highly flammable. For this reason, the solvent should not be heated under any circumstances.