Does Acetone also work for welding and smoothing PLA 3D printed parts?

Does Acetone also work for welding and smoothing PLA 3D printed parts?


Wha’s up every one, Tom here. And at this point it can be considered pretty
much common knowledge that you can smooth out the layer lines of 3D printed parts made
from ABS, HIPS and delikes with an acetone vapor bath. But I was told that this should also work
on some type of PLA like the ones from Dasfilament. I was intrigued because the common understanding
is that PLA shouldn’t be affected by acetone at all. But I mean I’ve got plenty of PLA printed
parts laying around so why not just try it out. So acetone is actually pretty cheap to get
hold of. This 1-liter bottle cost me just 2.99€ and
I use it liberally for things like cleaning paint stripping and anything that’s similar
to that. As a first step just to try and see if acetone
had any effect on PLA at all I decided just to dunk a piece in the acetone liquid and
after leaving it in there for a few seconds it started to get really sticky and gewy on
the surface and you could feel that layer coming off when you are rubbing it with your
fingers. Parts that are dunked in acetone like this
for an extended amount of time do get smoothed out but they do loose a lot of their stiffness
and I also think they loose a lot of strength so that not really recommended, but it got
me thinking before we even get in to the acetone vapor smoothing part I wanted to try out if
we could actually solvent weld two parts of PLA together. Essentially the way you do that with ABS or
PLA in this case is you take both sides brush some acetone on it let it dissolve just the
surface and the press those two parts together, it should get tacký and sticky right away
but it takes a few minutes or hours depending on how much acetone you put on there and how
big the surface is to reach its full final strength so I tried exactly that with two
clean surfaces of PLA pressed them together and while it was clear that they were immediately
sticking together I just set them aside for now. For the vapor smoothing i’m going to use the
tissues in the bucket method this is not a method I came up with I picked this up from
someone else and essentially what you do to get a very thick and consistent acetone vapor
is you take a few pieces of tissue paper use magnets to snap them to the inside of an old
paint bucket and then soak those tissues with acetone. If you want you can use some heat to speed
up the acetone evaporation but in general that is not really needed if you get the bottle
a good shake beforehand and turn it around a bit since what you dunk into the vapor bath
is going to have a dissolved and ideally a liquid surface to it you need some sort of
carrier to lift it out once your smoothing process is done I decided to just use this
angle bracket put the benchy on there dunked it in and pulled it out after about 30 seconds
or so, at that pont it was clear that the acetone was doing something the part felt
soft and squishy on the surface but there wasn’t any noticable smoothing going on
the one thing I did notce was that the surface was getting a bit dull but that was about
it so I gave the bucket a good heatup again refilled some acetone and set the timer to
five minutes put the benchy back into the bucket and waited it out after five minutes
it was obvious that the effect was a bit stronger that with the shorter test but other than
a softer and even less glossy surface there wasn’t really any smootging going on yet so
I decided to dunk this part in and just leave it for about an hour now while that is soaking
in let’s check back on the acetone welded PLA parts and see if we can seperate them
and by the feels of it these have really bonded well even hammering a screwdriver between
the two parts didn’t seperate them the screwdrived did deform the parts but they didn’t come
apart in this case I’d say these are very properley welded together there were no extra
adhesive used there was no super glue or epoxy or anything else involved there was just two
natural non sanded even PLA surfaces now let’s check back on the vapor smooth zoid buddah
this print has been in the acetone vapor for a good hour or more and still it dosen’t look
like the acetone vapor really did smooth anything out yes the part is slowley becoming softer
and more squichey but there is not a lot of melting and smooting going on so I guess if
you would really submerge you parts in actual liquid acetone and the smere it around with
your fingers that could work but acetone vapor smoothing for PLA is prittey much busted at
this point and just to cross check if the acetone bucket was even working at all I took
a part printed from regular ABS dunked that in there for twenty seconds pulled it out
and boom perfectley smooth I mean just look at that isn’t that an attracktive look for
the most part the trick was the vapor smooting ABS was not to leave the parts in there for
to long just let him soak but to give it quick dunkes in a highley consentrated acetone vapor
that way you only dissolve the surface and don’t get the entire part muchy but that in
detail is a topic for another video this video is sponsored by AlephObjects inc a free sofrware
libre innovasion and an open source hardware company headquarted in Loveland Colorado USA
and makers of Lulzbot 3D printers watch my review of both Lulzbot 3D printers here and
check the links in the video description for more info on these machines straight from
AlephObjects so okey while acetone dosen’t really do much for PLA when it comes to vapor
smoothing other than maybe making the surface a bit reflective it does work perfectley for
welding two PLA parts together witch I didn’t expect honestley so I hope you learned something
today aswell if you did leave this video a like subscribe and maybe even consider this
channel with a monthley pledge over on Patreon altso if you want to buy some acetone you
can acually do that on amazon the affiliate links that are in video description below
that’s it for today thanks for watching and I see you in the next one.

100 thoughts on “Does Acetone also work for welding and smoothing PLA 3D printed parts?

  1. I wonder if a redesigned 3D printer could apply a solvent vapor during printing to make the layers adhere better? I see there could be complications to this, I'm just trying to think outside the box a bit.

  2. Hi Thomas, just wondering: you put your fingers in the acetone without any gloves on. I thought acetone is bad for the skin?

  3. Not to be a drag but please be careful heating acetone! Acetone liquid and vapor are highly flammable, and over-exposure to vapors can cause nasty side effects. Especially using a resistive heat element to warm it, popping the top at the wrong time could bring a nasty surprise. And wear gloves to avoid contact dermatitis! Safety Officer lecture over, thanks for the video!

  4. I make an acetone-abs slurry and paint it on my parts when i need a really strong piece but don't need quality. you should try it.

  5. Real pla doesn't melt with acetone.. it does degrade tho. What it does melt is the pigment added to it.

  6. Just use any PLA solvent for smoothing and welding. "PLA is soluble in chlorinated solvents, hot benzene, tetrahydrofuran, and dioxane." THF isn't too bad to work with. Just don't let it sit around and crystalize.

  7. I use chloroform for smoothing PLA and making PLA glue to bind parts together. Allegedly DCM will work too, but never tried it. To be safe about it you have to vent the fumes somehow…If you don't have access to a fume hood, then you can build one, certainly not more complicated than the 3d printer itself.

  8. We have Patented PLA filament which is suitable for smoothing in Acetone, we also produce patented 3D reusable adhesive for printing.

  9. No, Acetone does not work for pure PLA. And not with good PLA Filament (nearly pure). Use THF instead.
    Though Acetone works on PETG, ABS, PMMA, ASA …

  10. FAKE NEWS!!! I tried to weld parts and it didn't work. Didn't even get soft. Disliked omg so fake??

  11. the welding technique you use , is actually the same technique we used at my shop to weld abs binding strip to wood for decorating guitars body and necks . and it works very well !

  12. keep in mind that about 90% of the plastic wich is sold as PLA is infact NOT 100% pure pla but a wild mix of different plastics they basically cut the relatively expensive pla with cheaper plastic waste to increase profit margins.

    i have had several types of pla all of wich werent pure and had vastly different propertys and melting temperatures .

    i obtained a certified pure PLA part and did some experimenting and acetone does not really affect it in any positive way it doesnt melt but it does tend to get softer as the plastic absorbs the acetone to a certain degree . after evaporation the pure pla becomes a LOT more brittle and has a dull coarse finish wich i assume is because the pla dissolved some ingredients of the pla while it left the superstructure intact

  13. I acetone all my pla prints. They are smooth and retain far more detail than vapour and abs. I simply dont understand why people dont experiment more.

  14. stop trying all those chemicals and try with the classic pvc glue of the plumbers, with a picel you give both sides to join and press lightly if effort then pass your finger through the union to remove the surplus and let dry about 10 minutes

  15. We found, by accident, that Acetone glued white PLA instantly. Brush some on, stick them together and presto! They were one. But later we discovered it had no usable effect on any other color. Maybe it was just the white pigment that was doing the bonding?

  16. I am expecting Acetone to be removed from retail shelves any time now. Until then, I'm glad I can still find it for the little that I need. I've been using it occasionally since the 70's when I was fabricating fiberglas kayaks and accessories and buying it by the gallon. It's nasty stuff on several counts and handling it like in this video like it's paint thinner or varsol just makes me cringe.

  17. I would like to see a robotic arm as a 3D printer attachment, with high speed polisher to polish external surfaces of the 3D print.

  18. I appreciate that you do the experiment yourself instead of simply accepting unexamined answers from the forum quagmire. Too often people simply don't try. Of course, it turns out that it doesn't work well for smoothing… but the fact that it can be used successfully for welding is huge for me. Acetone is so much cheaper than cyanoacrylate! And I already have it in my printing tool chest, so it's nice to know I can depend on that when I need to bond together a halved print. Cheers!

  19. I have heared at scool long in the past that aceton is toxic but I don't know how. Is there any risk of slow and progressive poisoning when tuching directly without gloves, is there a trick to remove all the remainings of aceton ( recomanded time of évaporation ? )

  20. Has anyone tried MEK (methyl ethyl ketone) or methylene chloride? Those are two solvents used extensively in plastic work. Either should work better than acetone for welding.

  21. Acetone, goes through your skin, and into your blood stream.
    It can even be used to deliver medicine without an injection.
    Wear latex gloves and never touch acetone with your bare skin.
    Now you know.

  22. You say (1:14) that a lot of strength is lost after treating with acetone. This is due to the acetone which has been absorbed into the plastic. I'm sure the part will regain its previous strength after all the absorbed acetone has evaporated away, perhaps after 24 hours?

  23. Perfect ! Exatly what i needed, Thanks Tom, Keep up the awesome vids, tips n tricks coming ! very grateful for the help being a n00b lol

    Hmmmmm… thinking…. Vapour smoothing with a modified water-humidifier device ? USB Humidifiers from Aliexpress like $3-4 and they make vapour, alot of mods needed though i think converting the humidifier parts to be resilient to Acetone, but ima gonna give this a try 🙂

    https://goo.gl/vVFtQJ

  24. I bought some isopropanol (isopropyl alcohol) from my local electrical store, just for cleaning the printer bed, but Apparently it can smooth PLA. I believe it's what the Polysher is based on.

  25. I've found acetone is pretty decent for paint prepping pla parts when I'm not smoothing them and want to pain parts en masse, I'll pour some over a part or dunk a part in and then let it all air out for a day or two and it ends up, at least with the white pla I use, with a nice matte finish that paint sticks to really well and while it takes longer to get all nice and ready it's more thorough and involves less effort than priming for a pretty similar effect.

  26. I have 99% iso alcohol can I use a paint brush to smooth and weld the lines together?
    And if I put it in a spray bottle and put it on mist would that work as well?
    I also got some ABS filiment so not sure if that can even be done using 99% iso alcohol?

  27. Try paint stripper. The stuff that has the warning not to use in a bathtub. Make sure it's done with a garage door open or outside though. The fumes are hard to stay safe from in an enclosed space. Even a respirator is only effective for a short period of time. It's known to punch holes in filters…so if u need to actually strip a bathtub I recommend a supplied air system lol. I know from welding acrylic that stripper is much stronger than acetone. I also know the little bottle acctached to the side of large cans is misleading, it said stripper sprayer …idk why the club bouncers escorted me out ?

  28. I like to use Nitrocellulose Clear guitar laqure spray. if you spray heavy it does melt the PLA layers whilst also giving your print a smooth shiny waterproof hard surface

  29. You did another video where you strength-tested various adhesives for PLA – it would be REALLY useful to test the strength of acetone welded PLA compared to your preferred LocTite superglue solution.

  30. You should really be careful touching solved plastic with your bare hands! You don't want polymer molecules entering your skin via the solvent. Who knows what havoc it can play in your body.

  31. What about cyclohexanone? I used to use that when I built disposable blood collection kits. We bound vinyl to acrylic, and there were other plastic parts, but I don't know if it was PLA, ABS, or PVC.

  32. Please be careful while working with acetone and wear gloves. Acetone absorbs carcinogens and poisons from surfaces and then this acetone mixture will be absorbed through the skin. Touching a print wet with acetone is equivalent to injecting the surface material including its dust and bacteria.

  33. How to utilize acetone after using this bath? It's not a very friendly substance for many species… Can it be neutralized by some easy way?

  34. PLA is just too vegan for me. I don’t like vegan stuff.

    It is way cooler to print with oil based stuff, dead dinosaurs 😀

  35. The acetone is probably acting more on the modifiers the manufacturers use in their PLA recipe than on the actual PLA resin.

  36. If I want to have something squishy, but not want to set up all the annoying things… than I just print something in PLA and let it about 5 h in the Aceton-Vape-Chamber. That gives me a squishy but nice looking print

  37. One thing that works for me is pouring acetone on a paper towel and rubbing PLA vigorously – it really polishes the surface quite well, but for thicker lines, you will still need to use sandpaper.

  38. Beside using acetone, is wet sanding a good move for finishing a PLA printed part or is water going to compromise its internal structure?

  39. For strength you dunk the part in acetone for about 10 seconds. Make sure your part has at least 2mm of wall thickness. I noticed when sanding that there where no layer lines. The part came out exceedingly strong to say the least.

  40. Very cool Tom!
    I didn't know about this until well just now, I like that it can be used for adhearing two parts together??
    Thanks for sharing and as always keep building?

  41. Didn’t work for my Chinese PLA. There was no effect whatsoever on the surface after pouring acetone over it. Still haven’t tried with my new PLA from another, more reputable, manufacturer.

  42. be very careful, acetone does release the isocyanates from plastic (not sure there is in PLA though) that goes straight from your skin into your blood. Latex gloves can protect only few minutes, best is use PP plastic bags as gloves, but theses too don't last much longer with acetone).

  43. Thanks! I was looking for something to 'weld' two PLA parts. I tried methylene chloride and MEK. I never suspected acetone would do it. But now that I've read some comments I think I'll just reprint my part in ABS.

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