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Acetone smoothing 3d print


How To Easily Cold Acetone Vapor Smooth & Finish 3D Prints [Step by Step]

Acetone Polishing (Smoothing) of ABS and ASA – a step-by-step guide

FDM (FFF) 3D printers often produce a final object that while being mechanically sound, tends not to have that ‘professional look’ that you or a customer want to see. You need a reliable, easy method of 3D print finishing. 

That’s where the Cold Acetone Vapor Bath process steps in. Finishing 3D printed parts the easy (safe) way. Yes, this was actually 3D printed…

Can I acetone vapor bath my 3D prints?

All ABS 3D prints can be acetone smoothed. Filaments that can be polished using this process are: ABS, ASA, PMMA, HIPS and Polycarbonate.

Other filament types are either unaffected by acetone or are damaged by it. If you’re looking for other 3D printing post-processing techniques, check out our PLA polishing article for details on smoothing out 3D prints that can’t be acetone smoothed. 

The following photograph is of a shower tray system consisting of a frame and different color removable trays before ABS Acetone Vapour Smoothing. The frame is made of Black ABS, and all trays are made in ABS of varying colors.

The following photograph show the same system after the ABS Vapour smoothing process. 

Not only do the finished parts look better, they now have a higher resistance to water ingress, and they can often be stronger than their non-polished earlier selves once fully hardened.

This is definitely our preferred method when we’re asked how to finish 3D prints – there’s just no better way to easily smooth ABS prints.

SAFETY WARNING!

Before continuing further, please make sure you acquaint yourself with the safety regulations pertaining to acetone (propan-2-one) and its use. It is your responsibility to use this solvent safely.

Obvious things to note for safety are:

  • Only use in a well-ventilated area
  • NO NAKED IGNITION SOURCES – acetone is extremely volatile and the vapors are Highly Flammable
  • *NEVER EVER* heat the acetone!! [See above]
  • Avoid breathing the fumes
  • Avoid skin contact
  • Keep away from animals and children
  • Be careful that you do not spill any liquid onto surfaces that might be damaged by acetone – most common household plastics are susceptible to some kind of damage from liquid acetone

The principle behind Vapor Polishing

You can acetone smooth ABS filament & ASA filament, both with acetone liquid or as vapor.

They dissolve readily in the liquid, and a concentrated atmosphere of the vapor will eventually have the same effect. It’s that ‘eventually’ part we are interested in (and not the acetone 3D print mess you’ll be left with if you leave it too long).

We want to melt the surface of the object just enough that the surface tension of the molten plastic smooths out any surface inconsistencies and then halt the process at that point before any structural damage occurs.

In some cases, it is possible to quickly dip an object into acetone liquid to get a polished surface, but this can be very messy and gives inconsistent results.

If you use the vapors instead you have much more control over the ABS smoothing and the final results. As the vapors can get to all exposed surfaces equally, there are fewer areas of uneven melting. There are also no run-off channels or drip marks induced into the surface of the object that direct exposure to acetone liquid may cause.This is our clear ABS filament, acetone smoothed.

What you will need –

  1. A well-ventilated area to work that has no exposed ignition sources.
  2. Wear the appropriate PPE – Safety glasses/goggles, mask, gloves, etc…
  3. An acetone-proof container (a large glass vase or a tin) big enough to hold the parts you wish to polish – preferably with at least 30mm clearance in ALL directions around the object to be polished – top, bottom, and sides.
  4. A loose-fitting lid, also acetone-proof. If your lower container is not transparent, you may wish to use a sheet of glass as a lid – this removes the need to keep removing the lid in order to see how the polishing is progressing (and not letting the vapours escape or dust get in).
  5. A flat, non-porous plate such as glass or metal, to raise the object being polished above any liquid acetone in the bottom of the container – This really needs to be at least 10mm above the surface of any liquid acetone in the container and much larger than the object to be polished as this reduces the chances of liquid acetone creeping up the sides and onto the object itself.
  6. Some sheets of plastic-free kitchen roll to use as a ‘wick’ for the liquid acetone.
  7. Somewhere dust-free to allow the surface of the polished object(s) to harden.
  8. A TIMER! Seriously.

You will walk away, forget it, only to return later to find that amazing print that you were once so proud of has now turned into a hideous misshapen lump of plastic, or at worst some kind of acetone ABS mess.

It might not happen this time or the next, but it will.

Getting started

Make sure your container is free from contaminants (this will be your acetone bath), then place a few sheets of the kitchen roll up the side and along the bottom of the container. This will allow the liquid acetone to wick up the kitchen roll, helping to produce a strong concentration of vapor at all levels within the container.

Find somewhere to work that has surfaces and materials that will not be damaged by acetone or the fumes. Acetone is a superbly-powerful solvent – you don’t want it dissolving things that you’d rather keep. It is a low-density liquid that has very little surface tension, so it splashes and ‘wets’ surfaces very easily.

To hold the kitchen roll sheets in position, place your metal support (plinth) onto them. Make sure that you arrange the kitchen roll in such a way that when it gets wet with liquid acetone it cannot fall down onto your printed objects, as that will destroy any chances of achieving an acceptable finish.

The following photograph shows the setup used in the acetone bath ABS of the soap trays seen above.

The soap dish is sitting on top of a plinth made from a small piece of glass stood on three 22mm diameter copper plumbing joints – an arrangement that stops any chance of liquid acetone reaching the dish via capillary action (or surface-wetting).

Things to consider about the process of 3D printing acetone finishing itself

Not all filaments are the same, even from the same supplier. For instance, due to secondary effects from the pigments that go to make up the colors of ABS filaments, different colors polish at different rates. This means you will need to monitor the polishing of different colored objects so that you can remove them at the correct time.

The polishing process not only softens the surface of the object, the fumes also penetrate into the body of the object. Depending on the period of exposure, you will need to ‘air’ the object for a period of time that is commensurate with the time that the object was exposed to acetone vapour.

Usually, this takes a few days. However, in some cases, the full mechanical strength of the object may not be realized until a significant time has passed – for high-density objects, this can take weeks, or even longer!

The polishing process continues for a while after you remove the object from the container – usually for about ten minutes. So don’t be tempted to leave it in too long.

The following photograph shows what happens to a part when exposed to the fumes for an extended period.

The hole in the center at the bottom is supposed to be round, and the lower edges are all supposed to be straight.

The ambient temperature affects the speed of the process – you are evaporating a volatile liquid after all.

  • Too cold and it can take ages.
  • Too warm, and the process goes too fast.
  • Too hot, and you may be looking for a new place to work/eyebrows, so NEVER apply heat.

Finally – you need to have somewhere totally dust-free to place the polished object while the surface hardens. If you don’t, any dust that falls onto the surface will become embedded in it. Permanently.

Polishing

This is the really easy part.

  1. Without getting any on your plinth, pour the acetone over the kitchen roll sheets you placed up the side of the container. You need to have enough acetone to cover the bottom of the polishing container to a depth of a millimeter or two.
  2. Ensure that there is no liquid acetone present on your plinth.
  3. Make sure that you have a fool-proof way of removing the object from the container after polishing without the need to touch it, or you will leave marks all over the surface where you make contact.
  4. Quickly place the object in the center of the plinth – try not to touch it again – you have just a few seconds to adjust the final position. The polishing process has already started – it is that quick! You don’t really want to leave fingerprint impressions on your work, do you?
  5. Place the lid on the container and start your countdown timer. I personally set the timer to 15-minute intervals for finely-detailed objects, and 30 for large solid objects.

Depending on how rough the surfaces of the object are, and how polished you want the object to be, the process can take from around 15 minutes to several hours.

There is ALWAYS a trade-off between the required surface finish and the loss of fine details. Only you can decide what is acceptable.

Once you are satisfied that the polishing is almost complete, carefully remove the object to a totally dust-free environment that has good ventilation. This stops most of the ever-present dust particles that are suspended in the air from falling onto the semi-molten surface of the object.

Note: The reason you remove the object from the container at the point just before you get the surface finish you require as the polishing process continues for a short while even after the object has been exposed to fresh air.
You can always put it back in the chamber later if you are not satisfied, but once the process has gone too far, the damage is irreversible.

After about 30 minutes, a ‘skin’ will have formed on the polished object that will stop dust particles from becoming embedded in the surface of the object.

Remove the object from your dust-free chamber without touching it, and put it somewhere that has good ventilation to allow the acetone to further leach out of the object. The object at this point has little to no structural integrity so be careful how you do this.

Depending on the solidity and size of the object, the process of removing the acetone can take from a few hours to many weeks before the full strength of the object has been regained.

Once you are certain that a good skin has formed on the object, you can speed up this process of solvent evaporation considerably by using a fan continuously blow air across the surface of the object – smoothing 3D printed parts effortlessly. 

Summary 

To recap, the filaments that can be polished using this process are: ABS, ASA, PMMA, HIPS and Polycarbonate.

Other filament types are either unaffected by acetone or are damaged by it.

Acetone 3D Print Smoothing: 6 Easy Steps

Estimated reading time: 2 min

In this article

  • 1. What Is It?
  • 2. What You'll Need
  • 3. A Word of Caution
  • 4. Smoothing Steps

Normally, FDM 3D prints show layer lines. Learn about acetone 3D print smoothing and create a totally smooth surface finish in just 6 easy steps.

What Is It?

An acetone-smoothed ABS print. (Source: Alexander Issal / All3DP)

One of the many things that fused deposition modeling (FDM) printers lack is the smooth finish you always get from injection-molded parts. Instead, you often get a matte, rough finish with visible layer lines. A popular way to get rid of these layer lines is to sand and fill until the surface is smooth. This method, however, takes ages to get anywhere close to smooth.

Another way that’s not only faster but also much better in preserving accuracy is acetone smoothing, which can be applied to any material that can be dissolved in acetone. The most popular filament to acetone smooth is ABS.

In this article, we’ll take a look at how you can acetone smooth your own prints. Follow along as we show you the process of smoothing the pictured BuddaYoda.

What You’ll Need

Materials for acetone chamber. (Source: Alexander Issal / All3DP)

There are countless methods of acetone smoothing your 3D print, some more dangerous than others. We have therefore constructed a simple design with normal household items. Here’s what you’ll need:

  • Towels
  • One transparent glass vase (a glass jar also works fine)
  • Magnets (at least six)
  • A plate
  • A small clay saucer (any structure that acts as a platform will do)
  • Acetone

Optional:

  • Aluminum foil

Acetone is a great tool for everything between cleaning your hot end to welding together two 3D printed parts. However, you need to know that acetone can also be very dangerous if used incorrectly.

Acetone is very flammable, so don’t use it near fire or something that can cause a spark. Also, be sure to work in a well-ventilated area since the vapor can cause headaches, dizziness, and a sore throat if breathed in too much.

Smoothing Steps

Acetone smoothing process. (Source: Alexander Issal / All3DP)

Now that you have prepared all of the materials, you can finally start acetone smoothing your prints.

  1. Fill the plate with water and place the clay saucer on it with the flat side facing up. We have added a layer of aluminum foil on top of it so that the model doesn’t stick and so that we keep that shiny surface from printing on a glass bed.
  2. Attach the tissues to the inside of your vase with the help of magnets. Then soak the tissues by pouring in small amounts of acetone and rolling the vase until everything is covered.
  3. Place your 3D printed model on the platform (clay saucer) and slowly lower the upside-down vase over it. It’s important that the water on the plate makes a seal so that the acetone won’t leak. In the beginning, you will see some bubbles coming out from the water, this is normal and nothing to be afraid of.
  4. Now you just have to wait until the layer lines have disappeared. It can take anywhere from half an hour to a couple of hours. (The Budda Yoda took just under two hours.) If you choose a transparent vase, it’s much easier to see the progress of your smoothing process (where there is no tissue) without guessing or having to remove it.
  5. When you feel happy with your print, you can carefully remove the vase and remove the print from the platform. Place it on something that doesn’t react to acetone. We recommend using a failed PLA print, preferably the ones that have stopped mid-print and left behind a flat surface with infill acting as an anti-sticking platform.
  6. The last step is to let your print dry from any acetone leftovers. Sometimes it just takes a day, but it can take many days for it to cure. When the part has been cured, you now have a 3D printed part that looks like it was injection molded!

 

Source: https://all3dp.com/2/abs-acetone-smoothing-3d-print-vapor-smoothing/

Tags: 3D printing actone fdm material post-process

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Processing of 3D printed models

One of the problems that all fans of FDM 3D printing, without exception, encounter is the ribbing of external surfaces. Since the technology itself is based on the sequential application of layers of plastic, this effect cannot be avoided. You can, of course, make it less noticeable by increasing the vertical resolution of the printer (i.e. applying thinner layers), but you won’t be able to completely get rid of the ribbing.


PLA 3D model before and after torch treatment. The internal structure is visible under the sagging outer layer

Almost from the very first days of the RepRap project, the search began for methods of processing finished models in order to smooth surfaces. Emphasis was placed on two features of thermoplastics: the ability to melt when exposed to high temperatures and soften on contact with the appropriate chemicals.

As a rule, heat treatment does not give good results - it is difficult to control the heating of the surface, and this eventually leads to plastic boiling, sagging or simply releasing toxic fumes. However, this method can be tried on solid PLA models.

Chemical treatment is more promising, but it also comes with its own set of challenges. In addition to technological problems, the problem of reagents is relevant - different plastics react with different solvents. If acetone perfectly dissolves ABS plastic, then it has almost no effect on PLA plastic. With limonene, everything is exactly the opposite.

The main chemical smoothing techniques still revolve around ABS plastic due to its high popularity and low cost of suitable solvents.

A typical ABS solvent is acetone. Its good dissolving power allows it to be used as an adhesive for component parts of ABS models, although a homemade mixture is usually used for this, produced by dissolving ABS chips in acetone. The same glue (only a thicker consistency) is often used to repair delaminations or cracks.

Along with increased aesthetics, an important factor in the development of smoothing methods is increased strength. The monolithic outer shell reinforces the models, preventing delamination and ensuring their tightness.

Hand shaping

Makeraser - a combination tool designed to also work on the outside of models models. However, processing with a brush is a laborious task, and even requiring a certain skill. After all, already softened plastic is easy to deform with the brush itself, that is, the hairs will leave a mark on the plastic, which may not even out before the acetone evaporates. It is possible to equalize pronounced irregularities with this method, but it is quite difficult to achieve a smooth surface.

The advantage of this treatment is the selective application of acetone, which avoids smoothing sharp corners. After all, a pyramid was built for Cheops, not a cone, right?

An attempt to create a special tool for manual processing was a device called Makeraser. Basically, it's a simple felt-tip pen with a reservoir filled with acetone or acetone glue and a built-in scraper to remove models from the platform. From a practical point of view, this tool is best suited for gluing parts of a model or applying ABS/Acetone glue to the build bed just before printing to combat underlayer curl.

Acetone dip

Failed surface leveling by dip

A more promising and simpler method is acetone dip. Exposure of the ABS model in undiluted acetone for about 10 seconds is sufficient to dissolve the outer layer of the model. The specific exposure time may vary depending on the quality of the original model and the concentration of acetone. Since the sale of pure acetone is regulated, a technical solvent can be used.

After exposure, the model must be exposed to air until the acetone has evaporated. The process may take about half an hour.

Although this method is quite fast, it is difficult to control the process. With excessive exposure, the model will simply begin to dissolve, quickly losing small features. In addition, contamination of acetone with plastic of the same color can lead to streaks on subsequent models dipped in the same solution. A more controlled process is acetone vapor treatment.

Probably the most efficient way to get glossy ABS models. This method requires placing the model in a container with a small amount of acetone at the bottom. The model itself should not come into contact with acetone, so the model should be placed on a platform or hung above the surface of the solvent. When installing on a platform, the material properties of the stand should be taken into account. Wood is not suitable for this task due to its porosity: the bottom surface of the model will stick to the wood, and it will be quite difficult to separate it. The best option is to use a metal stand.


It is advisable not to use wood as a platform

After placing the model, the container must be heated to increase the temperature of the acetone. Acetone also evaporates at room temperature, but too slowly. Please note that boiling acetone is not recommended, as this will cause condensation to accumulate on the model, which in turn can cause streaks. Thus, for best results, do not exceed the temperature threshold of 56°C.


A safe, homemade steamer that uses boiling water in an external pot to heat the acetone in an internal one.

Holding time varies greatly with the temperature of the acetone. So, when boiling, only a few seconds can suffice, while experiments at room temperature required up to 40 minutes of exposure. Fortunately, using a transparent container, you can determine the readiness of the model "by eye".

As with dipping, the completed model should be aired out before the outer surface hardens, avoiding unnecessary physical contact.

Both when immersing models in acetone and when working with steam, the wall thickness of the models must be taken into account. The shell must be thick enough to withstand the inevitable loss of the outer layer. In addition, especially subtle features may simply dissolve, and sharp corners will be smoothed out.

Safety Instructions

Successful Acetone Vaporization of an ABS Model

Acetone is not considered to be highly toxic, but care must be taken nonetheless. Inhalation of vapors can lead to pulmonary edema and pneumonia. A sign of poisoning is a feeling of intoxication, accompanied by dizziness. In addition, acetone causes irritation of the mucous membranes. When working with acetone, do not neglect personal protective equipment - goggles and gloves.

Particular attention should be paid to the flammability of acetone. Air mixtures with an acetone concentration of up to 13% by volume are explosive - when processing with acetone vapors, it is strongly recommended to work in a well-ventilated room and, if possible, use an exhaust hood. Do not use an open fire to heat acetone: since solvent vapors are heavier than air, they will displace air from the vessel, and once outside, they will cool and come into direct contact with the fire with all the ensuing consequences. It is also not recommended to tightly close the vessel, especially with strong heating, in order to avoid destruction under pressure.

Commercial options

Stratasys Finishing Touch Smoothing Station

In addition to the Makeraser described above, there are commercially produced units for steaming both acetone and other solvents - dichloromethane, butanone, etc.

Stratasys manufactures a little-known but successful Finishing Touch that can process any variation of ABS to a quality virtually indistinguishable from injection molded models. The process is facilitated by the presence of a recirculation system, which saves on solvent and prevents air pollution by potentially hazardous fumes.


Future installation Sky Tech MagicBox

The developers of the new Sky Tech MagicBox device promise compatibility of their device not only with ABS plastic, but also with PLA. True, they intend to achieve this using the same acetone, despite the low solubility of polylactide (PLA) in this solvent. However, even with the ability to work only with ABS, the new device will be a good tool, especially for companies using FDM 3D printing for small-scale production.

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How to smooth 3D printing?・Cults

Objects created with a 3D printer don't always look as good as they should. Even if visualization of 3D printed parts is usually acceptable, this may not be enough if the object is for sale or display. Some people just want a perfectly smooth and shiny surface for 3D printing. Fortunately, it is possible to achieve this level of perfection with the help of some suitable tools. This guide will show you how to smooth out ABS and PLA 3D prints for the best results.

The FDM 3D printer opens up endless possibilities for creating PLA 3D prints. However, parts may be printed with bad layers that need to be removed. If you're looking to give your 3D printed parts the shinier look, there are some easy ways to align your 3D printed PLA.

Use spray paint and polyurethane

The sanding method used to be the most common technique for leveling 3D printed PLA. Today there are new alternatives. You can use spray paint mixed with polyurethane to line up 3D printed PLA parts. To do this, you need to purchase the right tools:

  • spray paint,
  • polyurethane,
  • fan for drying parts.

The smoothing process is one of the simplest. First of all, it is necessary to clean the product so that dust or other dirt does not linger on the surface of the object. Use a spray can to cover the 3D print with a layer of paint. Then a layer of polyurethane can be applied to the part. Be very careful and place the freshly coated 3D print under a fan to speed up the drying process .

After a few minutes, you will find that the mixture of polyurethane and paint starts to fill in unwanted holes and imperfections on your PLA 3D print. Once completely dry, the part can be recoated with mix to remove any remaining surface imperfections. This method is less tiring than sanding.

Opt for XTC-3D Clear Epoxy

Although highly effective, using a mixture of paint and polyurethane to line a room can be too messy for some people. There are other alternative methods for anti-aliasing PLA 3D printing. Transparent epoxy resin XTC-3D has been specially designed to align PLA 3D parts for an optimal finish . The product consists of two bottles that need to be mixed for 3D printing.

Remember to mix the product well and follow the instructions correctly. Using a brush, apply the resin to the printed parts. The dried product will harden into a smooth transparent layer. PLA 3D printing becomes smoother and shinier. XTC-3D can also be mixed with dyes and stains if you wish to color your parts. You can also add effects such as metallic highlights or palettes.

Use 3D Gloop

This adhesive has been specially developed for smoothing PLA 3D prints. 3D Gloop can be used for various purposes. To smooth out a 3D print with this product, simply apply it to the printed part with a brush. It works like the XTC-3D, except it only has one bottle. This is a great advantage if you only want to use a small amount of glue. However, 3D Gloop is not without flaws. The product contains a number of toxic components. It should be used in a well ventilated area.

Acetone is a chemical stripper used by professionals to sand and clean certain materials. Due to its high toxicity, it should be handled with care in a well-ventilated area. Acetone can be used to level ABS 3D printing.

Learn more