• Gregory posted an update 3 weeks, 5 days ago

    Hello, I would like to know how Gael smooths his ABS parts. I’ve read many online discussions about using acetone and various vapor systems, but all of them appear to be somewhat unsafe since the efficient ones tend to incorporate heat. I’m looking for something where acetone can be brushed on or wiped on with a cloth, but that may not be possible. There doesn’t seem to be any commercial device available to buy, probably because of safety concerns.
    Gael, if you tell me your secret, I won’t tell anyone ;)

    • Hello,
      I do not smooth my prints for InMoov, the parts are straight from the printer. If the printer is well calibrated it all fits very nicely and the finish surface is very clean.

      When ever I need to smooth ABS for some other jobs, I put a bit of acetone in a jar with a closed lid. I set the part inside the jar on a small support, so the part isn’t directly in contact with the acetone. Then I just let the part a few hours in the vapors until I consider the surface smooth enough.

      Big secret.

    • Thank you for your feedback Gael. I was aware of the “acetone in a jar” technique but unfortunately it doesn’t work well for large (tall) pieces because the acetone vapors tend to stay at the bottom of the jar so the polishing is rather uneven. I shall endeavor to perfect a better method, hopefully without setting my house on fire :)

      • Gregory, I use the “Jar-Vaping” method as well. My parts are usually less than 200mm tall, however, this tip may help…

        1) Line the inside of the jar with paper towels, from bottom-to-top and secure them to the sides. ( i am using a paint can, so i just use magnets to pin the towels down. This will act as a wick and the Acetone will travel up the towels, allowing the vapors to spread more evenly.
        2) Fill the jar (about 20mm) with acetone.
        3) Use a metal (or similar) platform that will sit HIGHER than the Acetone level ad place it in the jar.
        4) Place your part in the jar, on the stand.
        5) Cover the jar with a (preferably air-tight) lid.
        6) Gael recommended waiting an hour, however, I would suggest checking your part every 10 – 15 minutes! I’ve left a part in the jar too long before and the Acetone makes them very soft and mushy. So, depending on your part, you may only need a few minutes (I usually start with 20 minutes, then check every 15 after that.) Remember, you can always keep it in longer, but if you destroy the part, you’ll have to start over.
        7) TIP: If your part comes out of the printer with a lot of rough edges or little nodules that don’t need to be there, Sand the part first (hand sanding works fine). This will help the smoothing process.
        8) TIP: After you’re done with the smoothing, re-cover the jar! the Acetone will dissolve in air quickly if you leave it open, but covering it will save the Acetone for later use… usually for days or weeks!

        Hope this helps!!!!

        • Hi Jeffrey,

          Thank you for your detailed rely. I have seen this “paint can” method before (I did mention that I’d seen various vapor methods). I was hoping to avoid using vapor and to use either a “brush on” or “clothe wipe” method. Your method does work well and your substitution of a glass jar for the metal paint can is an improvement because you can see what is happening inside. I would also add that you can use magnets (one on either side of the glass) to suspend the paper towel inside the glass so that it stays at the top and doesn’t fall down onto the object you are polishing. You’ll need rare earth magnets (super strong) to use with a glass jar (as apposed to the simple single magnet used with the metal can.

          I’m thinking there has to be another way to do this and my first thought is dissolving acetone in water. Acetone is quite soluble so it should be possible to experiment with various concentrations and time spans to see if a “dip” or “soak” method will work. This may have already been tried before, but I couldn’t find anything about it online.

          Gregory :)