PLA is without a doubt the most popular type of filament in the 3D printing world right now for many reasons, such as being a simple material to print with, being budget-friendly, and not requiring advanced equipment for optimal results.
That being said, just as with any filament, models printed with PLA can also have slight imperfections and defects that require post-processing, where being able to dissolve the material is often a significant part of the process.
As a result, we often hear questions regarding the optimal solvents for dissolving PLA filament; since a chemical that dissolves another filament type, such as PETG, may not work for PLA.
So, which solvent works best for dissolving PLA?
Here are some of the solvents that can dissolve PLA, ranked from least effective to most effective:
- Acetone
- Propylene Carbonate
- Ethyl Acetate
- Tetrahydrofuran
- Dichloromethane
Even though they are the less effective solvents in this list, we do not recommend using anything other than acetone, propylene carbonate, or ethyl acetate unless you have the experience and equipment to work with dangerous chemicals.
In the next section, we will be analyzing each of these solvents in better detail and take a glimpse at the application process and the safety precautions you should take before working with them.
Table of Contents
Which Solvent Works Best for Dissolving PLA?
While there are many solvents you can use to dissolve PLA, each of these options are entirely different than one another in factors such as effectiveness, safety, and availability.
As ease of use and effectiveness are inversely correlated in this case, we have listed the solvents from least (safest, most user friendly) to most effective (most dangerous, requires experience and equipment to use).
Acetone
Out of all the chemicals in this list, acetone is perhaps the only familiar one for most as it’s a common household item that you can most likely find in every home.
While acetone cannot dissolve PLA itself, it’s possible to use acetone to dissolve PLA filament that often is a mixture of PLA and other substances (usually lower quality filament).
As the effectiveness of acetone isn’t guaranteed, and the process takes a long time in cases where the acetone can successfully dissolve the PLA filament, it’s on our list as the least effective solvent.
If you have enough time on your hands and are looking to dissolve minor defects on your model, we recommend giving acetone a try before moving on to stronger chemicals.
Risk: Low
Effectiveness: Low
We highly recommend working in a well-ventilated area and using gloves, a respirator, and eye protection to stay as safe as possible.
Propylene Carbonate
A chemical that you can often find in commercial cosmetic and skin products, propylene carbonate is mainly used to dissolve certain ingredients and reduce the product’s thickness.
Propylene carbonate is a fantastic option for dissolving PLA due to it having a considerable degree of effectiveness while being a safe, low-risk chemical to use.
Unfortunately, propylene carbonate isn’t a widely available chemical, which makes it a challenge to find it for the purpose of personal usage.
If you can get a hold of it, propylene carbonate is a definitive upgrade from acetone that will make it easier for you to dissolve PLA.
Risk: Low
Effectiveness: Medium
We highly recommend working in a well-ventilated area and using gloves, a respirator, and eye protection to stay as safe as possible.
Ethyl Acetate
Ethyl acetate is a substance commonly used in glues, nail polish removers, and even the decaffeination process of coffee and tea.
A chemical with low toxicity, ethyl acetate provides the ideal balance between safety and strength for dissolving PLA and is the solvent we recommend for scenarios where acetone isn’t doing the job.
As ethyl acetate is widely available for reasonable prices, you shouldn’t have any difficulty finding it, unlike propylene carbonate.
Due to propylene carbonate not being widely available, ethyl acetate is the most likely upgrade to acetone, but it also requires a higher degree of caution during usage.
Risk: Medium (Use with caution)
Effectiveness: Medium
We can only recommend working with ethyl acetate in a well-ventilated area with gloves, a respirator, and eye protection.
Tetrahydrofuran
As an industrial solvent, dissolving PVC is the most common use case for tetrahydrofuran.
While tetrahydrofuran is on our list due to its high effectiveness for dissolving PLA, we DO NOT recommend its usage in any shape or form unless you are a professional with the necessary equipment and experience.
Risk: High (Do NOT use)
Effectiveness: High
We DO NOT recommend using tetrahydrofuran for anyone who doesn’t have the necessary experience and equipment.
Dichloromethane
Another solvent with serious risks – dichloromethane is primarily known for being an ingredient in paint strippers in the past.
Similar to tetrahydrofuran, dichloromethane is only on our list due to its effectiveness as a solvent for PLA. We DO NOT recommend its usage unless you are a professional with the necessary experience and equipment.
Risk: High (Do NOT use)
Effectiveness: High
We DO NOT recommend using dichloromethane for anyone who doesn’t have the necessary experience and equipment.
How to Dissolve PLA with a Solvent?
There are many ways to dissolve PLA with a solvent, depending on the solvent you use and your use case for dissolving.
Here are some of the widely used methods:
- Vapor smoothing – Vapor smoothing is a technique that involves using the fumes of the solvent to smoothen the model. This technique is often combined with sanding to remove imperfections such as layer lines throughout the model.
- Applying solvent to an area – Applying the solvent to the region where a defect (such as a blob) exists is perhaps the most common way of using a solvent. With this technique, you can quickly get rid of slight imperfections on your model.
- Placing the PLA directly in the solvent – Placing parts of the model in the solvent is another way of dissolving it. Removing the supports of a model cleanly or making PLA slurry are the most common reasons for using this technique.
Does Acetone Dissolve PLA Filament?
Dissolving PLA filament with acetone is a controversial subject, as PLA itself does not react with acetone.
Whether acetone will dissolve PLA filament or not largely depends on the quality of the filament.
The higher quality filaments are less likely to dissolve in acetone due to their high PLA content.
On the other hand, lower quality PLA filaments often contain other substances that react with acetone, allowing the filament to dissolve.
That being said, even in cases where acetone can actually dissolve the filament, the process takes a considerably long time compared to most other solvents.
As a result, we only recommend using acetone in cases where time isn’t an issue and for small areas where you don’t need the plastic to dissolve entirely.
Does Isopropyl (Rubbing) Alcohol Dissolve PLA?
A common question in the community is whether isopropyl alcohol (IPA) can dissolve PLA or not, as it’s possible to observe plastic surfaces cleaned with IPA show a certain degree of reaction, such as the plastic discoloring.
Unfortunately, isopropyl (rubbing) alcohol cannot dissolve PLA, even if you leave the PLA in isopropyl alcohol for extended amounts of time.
While a phenomenal substance for cleaning your models and your print bed, IPA won’t have any noticeable effect for dissolving or smoothing your model.
Wrapping Up
Although numerous solvents can dissolve PLA, we can only recommend using safer options such as acetone, propylene carbonate, and ethyl acetate at home.
As chemicals such as tetrahydrofuran, and dichloromethane are extremely dangerous, we DO NOT recommend using them unless you have the necessary experience and equipment to carry the procedure out safely.
In a scenario where the safer chemicals don’t work for you, our recommendation is to consult a professional who can perform the necessary steps in a safe environment.
Finally, make sure to follow the necessary safety precautions regardless of the solvent you’re using, as safety comes before anything else.
Happy printing!
Mike started his 3D printing journey with the Anet A8 when it first came out back in 2017, and has been obsessed with 3D printers ever since. Nowadays, he primarily uses his Ender 3 to print functional parts that make his life more convenient whenever possible.