Making Your 3D Printed ABS Parts Smooth With Vapor Treating

Since people print with RepRaps, they also treat their ABS parts with acetone. This usually involves either dipping the part into liquid acetone, which causes white streaks in the parts, or brushing the acetone onto the part but that is a messy process (needs to be mixed before it can be applied).

Neil Underwood thought it was crucial to invent a way to do this cheap, clean and fast. And he came up with one. To do this process you will need your RepRap’s Heated Build Plate (must be able to reach 110C), a glass jar, some aluminium foil, and a hanger to bend into a hook to get the parts out with.

Take a look at the video:

Do please be careful with the use of acetone. Acetone’s flash point is −20 °C (−4 °F) and air mixtures of between 2.5% and 12.8% acetone, by volume, may explode or cause a flash fire. Also be careful that Acetone has slight toxicity in normal use, and acetone vapor in work areas should be maintained at or below the Threshold Limit Value of 750 PPM. At very high vapor concentrations, acetone is irritating and, like many other solvents, may depress the central nervous system or cause irritation of the respiratory tract, headache and loss of memory.

When you follow these steps explained in Neil’s blog, you should be alright:

First place your glass jar on the heated build plate and put a liberal amount of Acetone into the bottom of the jar (3-4mm deep). Initially you need to ramp up to 120C, especially if you have a heavy jar.  As the jar comes up to temp you will see the meniscus from the edge of the vapor cloud slowly creeping up the jar.  Once the vapor is to the top of the jar, turn the plate back down to 90C for the treatment.

Place your sheet of aluminum on your table, and your part on the sheet.  Lower the object into the vapor bath (very carefully, you don’t want it falling off).  Leave the object in the acetone until you are happy with the amount of smoothing (the object continues to smooth out over the next few hours).

Once the parts are in process you can not touch them at all, the easiest way we have found to get the parts in and out of the jar is to fold aluminum foil  into a make shift table and use another smaller sheet of aluminum to act as a base for the part.  You can fish the parts out of the jar using a wire coat hanger bent into a make shift flat hook. 

When done, carefully remove the object from the bath.  If you’re done processing put a lid on the jar loosely and as the vapor cools it will condence back into liquid to be stored in your acetone jar again. Allow the part to sit for another ten minutes, the surface will be very squishy while the residual acetone dries off.