If you’ve been creating objects with your 3D printer you will have noticed the small ridges throughout the print that are caused by each layer of ABS plastic being deposited. One way to remove these ridges is by using acetone to smooth them out.
Neil Underwood, RepRap Blog, wasn’t satisfied with the results of existing acetone methods which can give inconsistant results; such as dipping the part into liquid acetone or brushing the part with acetone. Deciding to take the cheapest possible route to a solution he used his RepRap’s heated build plate, a large glass jar, aluminum foil and a wire hanger bent into a hook to retrieve the part from inside the jar.
To smooth an ABS printed part using the acetone vapor method, first pour acetone into the jar to around 4mm depth then place the jar on the RepRap 3D printer heated platform and heat the bed to 120 deg C. The acetone will vaporize and onces the vapor level has reached the top of the jar reduce the heated platform to 90 deg C.
Place the ABS object you wish to post-process on an aluminum foil platform and use the wire hanger to gently place it into the bottom of the jar. Leave the object in the jar until the ridges have disappeared.
As you can see in the above photo the results are quite impressive for a DIY solution. The finer the print resolution (layer thickness) of your 3D printer, the less time the vapor needs to smooth a printed object. If you want to try this, be careful, as acetone can be toxic and air / acetone mixtures of a certain ration can explode.
A DIY acetone vapor bath such as this might be the only option to smooth ABS prints as Stratasys have a pending patent application that covers this process. It’s not yet been granted, but don’t expect to see a product like this on the market anytime soon.