How do I give 3D-printed parts in ABS a shiny smooth finish?
Acetone can be used to smooth ABS.


The left has been smoothed by an acetone bath and the right is the original model. (Image credit: Andrew Sink)

Take note: acetone is dangerous to breathe in, so work in a well ventilated area. It is also flammable.

Warm acetone vapour bath using stove

This method involves suspending the model in a glass jar of boiling acetone that is heated up by a pot of boiling water.


Attach the model to the lid of the jar with some string, keep the string short, so the model is close to the lid.
Put a few centimetres of water in a pot
Place a rag at the bottom of the pot (to keep the jar stable).
Place the glass jar in the pot, on top of the rag.
Place the pot on the stove and heat to 110°C.
When the acetone is boiling place the dangling model into the jar.
After a few seconds, remove the model.


See here for a step-by-step guide with pictures.

Warm acetone vapour bath using printer bed

This method elevating the model in a glass jar of acetone that is heated up by the printer's heatbed.


Find a non-soluble object that the 3D model can stand on.
Put a teaspoon of acetone in jar.
Place the jar on the heatbed and heat to 110°C.
Place the stand into the jar.
Place the model on the stand, the stand should not let the acetone touch the model.
After a few minutes, remove the model.


See here for an example.