Introduction: ABS 3D Printing Finishing Technique Comparison

this is a comparison of ways to acetone finish 3D printed materials that i saw other people uses.

  1. The "fan in glass"
  2. The "lined bucket"
  3. Combination
  4. (extra) Clear nail polish coat

And i'm also comparing 2 different materials, ABS and PLA. They say that PLA wont react to acetone, but why not try it anyway.

I printed the form with various kinds of surfaces, edges, points, and shapes to see if the acetone will have different effects on them.

Step 1: The Form

I made this form to see the effects of the acetone on different types of shapes.

It has:

  • cones
  • pyramids
  • concaves
  • round
  • organic
  • scale texture
  • pointy & dull cones
  • prism
  • channels & valleys

Step 2: Materials

  1. acetone proof receptacles.
    • any container that can be somewhat sealed, large enough to fit your printing, and acetone proof can be used. I'm using pet bottles because it is acetone proof, easily modified, and disposable.
  2. cotton / tissue paper / paper towels
    • things that can line the insideof your container with and absorb acetone. It will absorb and release the acetone vapor slowly in your container.
    • i recommend to use paper towels because they are the most durable. Cotton and tissue breaks apart to easily
  3. acetone (i used a can of paint thinner)
  4. your 3D printings
  5. a small computer fan
    • i rewired mine to work on a phone charger

Step 3: The Fan in Glass (building)

The concept of this technique is to maximize the usage of acetone by having it circulate within the rig, so even just a small amount of acetone should be enough. The circulating gas would also create an even finish on the entire surface.

Building:

  1. cut the top and base of a PET bottle, forming a tube
  2. suspend the fan in the bottle in such a way so it will also fit with your printing (here i used bamboo skewers)
  3. use the cut base part of the bottle and stuff it with cotton/tissue paper
  4. drench the cotton/tissue with acetone
  5. cap the modified base at the top of your tube
  6. put the printing inside the rig
  7. turn the fan on
  8. check the printing every hour or so

Step 4: The Fan in Glass (result)

ABS:

After 3 hours of treatment, there is no noticeable difference on the printing. No shine, no melted layer, nothing.

I think this is because the rig is not air tight enough so the acetone vapor leaks, and adding the fan also accelerates it.

And having only the top part of the rig to be lined with acetone dipped cotton/tissue isn't enough to create the minimum amount of acetone vapor.

PLA:
No difference whatsoever after 3 hours of treatment

Step 5: The Lined Bucket (building)

The concept of this technique is to basically have the maximum amount of vapor possible, by lining the entire inside of the rig with acetone tissue/cotton. A brute force approach, if you will.

Building:

  1. cut a pet bottle in half
  2. line the inside of it with acetone dipped tissue/paper towel
  3. cut another pet bottle at the base
  4. flip the cut base
  5. put the printing on the base, use a flat service like a piece of cardboard or art carton
  6. put the half pet bottle over it, covering the whole thing
  7. check the printing every hour to see if there's a difference

Step 6: The Lined Bucket (result)

ABS:

After 3 hours and 30 minutes of treatment the result are very clear. there are very few visible printing lines.

It works really well on round and organic surfaces, having equal quality to injection molding

There are visible at large flat areas and wide concave parts. But it is most visible at "valleys", narrow spaces between protrusions, this is because the air there doesn't move, so the acetone didn't have the chance to react.

Theoretically you can let it soak in the vapor for a bit longer and those areas will eventually shine, but it will over saturate other areas with the acetone and melt them completely.

Finishing with acetone also get rids of any pointy shapes, the all get rounded off.

And keep in mind that you have to let the printing rest for around 2 hours after taking it out of the vapor, as it is still soft and easily deformed. Pointy and thin parts will reharden the slowest, so try not to touch them.

PLA:

No difference whatsoever after 3 hours of treatment, just feels a bit slimy, like a very thin film.

Step 7: Combined (building)

The combination of the 2 aforementioned techniques, it uses the large amount of acetone vapor and circulating air. The best of both worlds.

Building

  1. cut 2 pet bottles at 2/3 from the bottom.
  2. line one of them with acetone tissue/cotton at every side
  3. line the other one just at the base and find a way to hold the papers there,since were gonna turn it upside down
  4. some how hang the fan in the middle of the now upside down bottle.(again with the skewers from me)
  5. put the printing on a small surface, then put it in side the right-side-up bottles, and make sure the printing touch the acetone tissues.
  6. combine the 2 parts together.
  7. turn on the fan
  8. wait till its finish, check every hour or so

Step 8: Combined (result}

ABS:

After over 6 hours of treatment, there is very little acetone vapor left. And the results are a bit different than the bucket technique.

Whereas the bucket creates very smooth surfaces in most areas and unfinished in some, the combined technique makes a more even finish across all surfaces, but not as good or as fast as the bucket lining technique.

I'm still sure that this is because the rig is not airtight, and if it was it would have made the best finish of them all

It still has the same effect on edges and points, they got rounded and lose their acute angle.

P.S. this experiment shows that it is not ideal to use tissue paper as a saturation medium for the acetone. When i tried to get the printing out, the lining on the sides are starting to collapse and grazed the sticky surface of the printing. And it resulted in small pieces of tissue fused on to the surface of the printing. Use a more durable medium, like paper towels. and if you really want to use tissue paper or cotton, make sure to have something to hold them down and prevent them from collapsing

PLA: No difference whatsoever after 3 hours of treatment, just feels a bit slimy, like a very thin film, then returns to normal texture after a few minutes

Step 9: Extra: the Resilient PLA

Since nothing I tried work on the PLA, i decide to completely submerged one in acetone, and coat one in clear nail polish.

1. The coated piece didn't turn out very well. It's shiny, but it has brush marks all over and looks cheap.

2. After 3 hours of soaking there is no immediate noticeable difference in texture, but the printing became more flexible, able to be squeezed and return to its original shape. The bond between layer also became weaker, easl=ily separated and split. After the excess acetone is gone, the surface although look the same, feels very sandy compared the original.

Step 10: Final Notes

  1. use an airtight container so the actone wnot leak. If you are using one that is not, usage of a fan will accelerate the leaking.
  2. make sure there's plenty of room, you don't want the printing to touch the inside of the container
  3. don't use mediums that easily break apart to soak the acetone with, try using paper towels
  4. using fans will create a more even finish, especially in little nook and crannies
  5. pointy tips and sharp edges will become rounded, and especially prone to be deformed because they took the longest to re-harden
  6. use a flat, easy to peel off surface to put the printing on, the printing will be sticky, so you want to out it in something that is easy to pry from
  7. more suited to round and organic shapes
  8. usage on geometric shapes will cause uneven and imperfect wave and bumps