This is an instructable to do Acetone smoothing of 3d prints in a simple manner that works and is relatively cheap and simple without heating and being able to judge how its gone so far.

I have previously tried putting the print above a pool of acetone and letting it passively vapourise, but the vapours never seemed to go very far up inside and the print would come out half smoothed. So I went looking for another way. I didnt really want to heat the Acetone due to the nastiness of the product and just wanted something simple.

I saw somewhere along the lines (and cant find it anymore) where someone put a layer of tissue around the inside of a can, to allow the flow of acetone vapours, which are heavier then air, to form and flow down to the print. I tried this and it worked fairly well, though was hard to work out how it was going due to not being able to see. After much trial and error, I came up with the glass vase method.

Items needed:

Glass vase with narrow waist - $6 Au
Acetone - $10 au
Cheap Glass Chopping Board or two - $2 Au each
Tissues or similar absorbent paper - Free?
Syringe and Tube (optional) - $4 Au for the tube from a pet shop, $2 Au for the syringe from a chemist

Step 1: The Vase

To find the vase, I went to a homewares type shop. One of those shops that has lots of stuff to strategically place around the house that do nothing functional and look pretty.

Find a vase you like, then flip it over in the shop and make sure that the top is ground down level, some are better then others, even amongst the same batch. Once you have one you like purchase it and bugger off home.

Mine was about $6 Au.

Step 2: Pack the Dispersion Material

ie. Push a bunch of tissues or similar material into the bottom. The waist shape of the vase holds it all in place quite nicely. There shouldnt be any need to replace this anytime soon. The stuff I have has been in there for quite a while now and shows no signs of deterioration.

Step 3: Spacing

Put your parts to be smoothed on the glass chopping board, and space them so that they are not touching each other, yet still fit under the vase.

Step 4: The Acetone

Any form of Acetone will do, I bought it in a 1 Litre bottle as not much is required.

I also got a 25ml syringe with a piece of tubing that had a 4ml interior diameter from a pet store (used for air lines on fish tanks) so that I could accurately use a small amount each time. The hose and syringe is also quite useful for filling up nail polish bottles!

I use a whole syringe of acetone per run and it seems to work quite well, feel free to change the amounts to suit.

Squirt the acetone all around on the tissue, and flip the vase over and place on top of the items. I pump the syringe a few times to clear any leftover acetone and then pull it apart to dry. It hasnt melted yet!

Let it sit until you are happy with the level of detail still left on the model. Once done, simply take the vase away and leave the chopping board somewhere to dry.The time will depend on the ambient air temp. The above took about an hour due to winter kicking in here (Northern Australia) and it being early evening. It was down to about 17 degrees Celsius. Normally I do it during the day and it only takes 20-30 mins. Adding some warmth would of course decrease the time required, but this is simple and easy method!

If you liked this instructable, please vote for it in the competition!

If you want a faster method, MechEngineeringMike has an ultrasonic smoother - https://www.instructables.com/id/Ultrasonic-Misting...

Models shown were

Firefly ship - http://www.thingiverse.com/thing:11348

Iron Man Ring - http://www.thingiverse.com/thing:112672

Viper - Scratch built, working on making some really small vipers for Full Thrust rules, this one was way too big.