Safe Way to Do Acetone Bath

Acetone bath is a great way to make your 3D-printed models look awesome. However, since we are dealing with acetone vapours the whole process is quite dangerous to perform.

This is the fastest and the safest way to do acetone bath that I have developed so far. You will need common household tools and items. It is the safest way I know but still don't forget to open windows and don't use open fire! Or you will experience a HUGE fireball.

Acetone vapour is probably the best medium to polish/smoothen 3D-printed models. Acetone boils at 56°C/133F. We need to hold it in slightly higher temperature to make it boil slowly and continuously. The temperature needs to be not too low but not too high either.

Water seems to be a perfect medium for this purpouse. It can hold temperature from 56 to 100°C/133 to 212F quite a long time.

So the principle is:

1. Pour acetone in the inner pot
2. Put model in the inner pot above acetone level
3. Pour boiling water in the outer pot
4. Wait a while. It should not take more than one minute
5. Take the model out.

Acetone will only work with ABS or PET items. If you are using PLA or Nylon you will need some other solvent.

Step 1: Prepare the Items You Will Need

1. A pot and a cage that fits inside it.
2. Kettle
3. Another larger pot. We will put the first pot inside it. Let's call them inner pot and outer pot.
4. Acetone

Step 2: Boil Some Water

Pour about 0.5 liter of water in the kettle and make it boil.

Step 3: Prepare Acetone

Meanwhile put inner pot in the outer pot and pour some acetone in the inner pot. About 0.5 deciliter should be enough. The larger the model the more acetone you will need. The model must not touch acetone level!

Step 4: Prepare Your Model

1. Put your model in the cage.
2. You can put aluminium foil on the bottom to prevent the model to merge with the cage while it is being etched by the vapours.
3. Put the cage in the inner pot with acetone.
4. Cover the pot.

Step 5: Make It Boil!

Pour boiling water in the outer pot. You should immediately hear acetone boiling. Model should start to look wet and you should see the edges are more and more smooth. Don't let the model in the vapours for too long or bubbles will start growing on the surface of the model. When you see the model is smooth enough, get it out with the cage.

Don't freak out when you put your hand inside the inner pot. The vapours inside are hot but not dangerous and it is a very strange feeling.

This step should not take more than 1 minute.

Step 6: Dry Up

Now we want the model to dry up. Put the cage with the model outside and wait about 10 minutes.

Step 7: That's It

Model is now smooth and shining. Since I know this method I am not printing at .1mm resolution any more. I am only using .3mm layer height and then I boil it in acetone vapours. The final result is the same but printing process is much faster.

As you can see, large holes are still not smoothened properly. You will need to use some other technique to make them look nicer.