A hot plate, a mason jar, and a small amount of nail polish remover have been MacGuyvered into a workable solution to smooth out those rough edges on your homemade 3D printed items. The technique comes courtesy of two makers who, after observing others attempting to create a smooth look, began experimenting with the process themselves.
Makers Austin Wilson and Neil Underwood set out to improve upon the general method of using acetone (nail polish remover) to tame the rough edges. Acetone was applied either by hand with a brush, or the object was dipped into an acetone bath. Neither technique provides particularly elegant results - and then there is that messy business of acetone being a pretty toxic solvent with a low evaporation point that can be overinhaled easily.
After seeing some interesting (think a deep-fryer and cooling systems), but complicated ideas their goal was to make it simple. Their solution involves simply placing an ABS-based printed part in a mason jar with a few ounces of acetone on a hot plate. When heated to 90 degrees Celsius the acetone evaporates, but creates a cloud that is heavier than air. The cloud surrounds the model and melts the surface; after a couple of hours for cooling and solidifying the item has a mirror finish.
Wilson and Underwood are members of a hackerspace called Fablocker and clearly this isn't their first time around the block with creating alternate solutions to these kind of problems. They aren't keen to rest on their laurels with their tests involving 3D printed model squirrels; they are still experimenting with temperatures and exposure times.
They are quoted in Wired as also being interested in further exploring how the process changes the physical properties of the item:
"It doesn’t really seem to change the shape of objects or alter the dimensions, but we haven’t had time to do test cubes and measure them with calipers,” says Wilson. “If anything the smoothing out process might make things work better. People have tried to use 3-D printed models as bushings and axels before, but they never work because they’re too rough.”
While the duo have easy to follow instructions on their site, it's probably a good idea to remember these guys have been in the game for a while and they are familiar with the volatility of acetone. They even have a video (posted below) which shows what happens when an experiment doesn't go to plan.
The moral of this story? There are some great solutions out there for all you DIY'ers and makers looking to achieve that perfect 3D printed item; just don't go into it without goggles, gloves and a fire extinguisher nearby.