Are you interested in smooth PLA 3D prints but don’t know where to start? You’re not alone! Many people are interested in getting glossy prints without the hassle of working with ABS.
While you can’t use ABS acetone smoothing on PLA prints, there are several other ways to make them look smooth. Whether you just don’t like the 3D printed look, want to sell your prints, or need a smooth piece for certain applications, PLA smoothing is fast and easy.
This article explains the different methods people use to smooth PLA plastic, how to use them, the pros and cons of each method, and when it is better to use one method over another.
What is PLA Smoothing?
Smoothing PLA is the process of removing the lines that are visible on 3D printed parts during the printing process. A smoothed 3D print becomes just that: smooth. The outside of the print loses the 3D printed look and appears more like injection-molded plastic.
PLA is one of the most common 3D printing materials because it is easy to use, cheap, and readily available. PLA prints at a low temperature and does not have a strong tendency to warp (unlike ABS filament), making it a good choice for beginners.
There are many ways to make a PLA print look smooth. usually, you remove the plastic that is visible and makes the layers look like stairs. Another way is to fill in the tiny gaps between the layers with some kind of brush-on coating. Each method has its own benefits and drawbacks, and some methods are better for certain projects than others.
Why Smooth PLA 3D Prints?
There are several reasons to smooth PLA 3D prints. The most common one is for aesthetics. Many people don’t like the lined look of 3D prints and would prefer to remove them. This is especially true if they are making money with their 3D printer by selling 3D prints, since their customers may not appreciate the rough texture.
Sometimes you will need to fill in or remove your layer lines for certain applications. For example, if you are using the print to make a mold out of silicone, you might want to smooth it so the texture isn’t transferred and so that casting materials like resin end up being glossy instead of matte.
There are several ways to make your PLA prints smoother. One way is to coat them in epoxy. This will seal the layers and protect them from moisture and dirt. It is especially helpful if you plan to use your prints outside. Another way to make your prints more resilient is by sanding and spray painting them. This will give them more water and heat resistance.
Epoxy coatings can also help to make your PLA food safe.
Methods to Smooth PLA Filament Prints
A popular method to get rid of roughness and defects in 3D prints is using epoxy resin coating. One of the best epoxy resins to achieve a smooth finish is XTC-3D. This two-part epoxy is known to generate heat while curing, making it capable of working well with low-temperature PLA prints without the risk of warping. Not only does XTC-3D cure at a lower temperature, but it is also engineered to avoid damaging your prints.
XTC resin is a unique type of resin that solidifies once mixed with a hardening agent, moving from liquid to solid. To achieve a smooth finish, paint a thin layer of the liquid on the print, and let it cure.
Resin coatings like XTC are not only straightforward to use but also produce outstanding results. They fill in the crevices between layers and grant a lustrous sheen. After the application, you can sand and paint the print for your desired look.
Be cautious when handling epoxy resins like XTC-3D. Always use it in well-ventilated areas, and put on gloves and goggles to avoid direct contact with your skin and eyes. Make sure to review the MSDS of the product for more information about safely handling epoxy resins.
Another useful product to smooth PLA, ABS, or PETG 3D prints is 3D Gloop, a versatile adhesive that works as a brush-on coating. Although primarily designed for coating the print bed and gluing 3D printed parts together, 3D Gloop is a fantastic option to produce smooth PLA prints. 3D Gloop’s formula works best with different filament types, so ensure you purchase the PLA product for smoothing PLA prints.
Unlike XTC-3D, 3D Gloop does not require mixing. You can easily apply it on your print bed with a brush in thin layers straight from the bottle and let it dry.
When handling 3D Gloop, you should also be mindful of the fumes produced during the process. You should use it in a well-ventilated area or with a respirator. Additionally, wear gloves and goggles to avoid contact with 3D Gloop. If you’re already printing with resin, you might have this equipment on hand.
Sanding and Painting
Sanding PLA can give great results
One way to make your PLA 3D prints look better is to sand and paint them. This process takes a lot of time, but it’s worth it because the results are excellent. When you sand, you remove the layer lines physically. When you use other methods, you fill them in.
Sanding and painting will give you the most control over your finished piece. This is the best way to go if you want to 3D print a helmet or create 3D printed cosplay armor.
Start by sanding your print with a rough sandpaper, like 100 grit. Sand down all the layer lines and areas you want smooth. Then use a finer sandpaper, like 200 grit, to do it again. Keep repeating this process until you’re done.
Make sure you don’t skip grits when sanding PLA
If you want a very smooth surface on your 3D print, you can keep sanding until you reach 2000 grit paper. But this may be more than you need. If you plan to prime and paint your piece, it is likely that you will not need to go that high. Assess your print after each grit and stop when you reach the texture you want.
You can use a wood filler or other filler primer before sanding to fill in some of the layers. This will help you avoid having to sand as much and it will also give your print a nice surface texture for holding paint.
You can use any type of paint you want to on your print. If you want to use spray paint, it will work well for a large print. If you want your print to look shiny, you can use gloss paint.
Remember that wet sanding (using wet sandpaper or keeping your print submerged in water while sanding) is best for PLA prints since it keeps the friction from melting the plastic and keeps you from inhaling the dust particles from the PLA. It can take a while to finish using this method, but it holds paint very well and looks great.
Be careful not to overheat your PLA prints when smoothing with a heat gun
If you want a non-chemical way to smooth your 3D prints, you can try using a heat gun. This method can be very effective, but it is difficult to do without accidentally melting your prints. Be sure to practice on failed or broken prints first.
If you want to make your PLA 3D print look smoother, you can use a heat gun. The heat will melt the outside layers of the plastic and remove the layer lines. Make sure to move the heat gun around the print so that it heats evenly. When the surface of the print looks wet, turn off the heat gun and let it cool.
This is a technique to make your floor look smooth. You can use this if you don’t have a tool to make it smooth. It might not work the best, so you should only use it if you don’t care about the results.
PolyMaker PolySmooth PVB Filament
Printing with PolyMaker’s PolySmooth PVB Filament is a process that simulates a PLA filament, but with a low-temperature filament that can be smoothed using isopropyl alcohol. The process involves the implementation of an ABS acetone smoothing process, but with the added benefits of usability with PLA or PLA+ filaments.
Notably, PolySmooth is a convenient filament due to its ease of use. The temperature at which it prints is low, like a PLA filament, and it does not require the use of a heated bed or 3D printer enclosure. What is more, a smooth print is achievable within minutes by spraying alcohol onto the finished model. The alcohol works by breaking down the outermost layer of plastic, leaving a polished and refined surface much like that of a vapor-smoothed ABS.
The PolyMaker Polysher is a useful tool that can be used in conjunction with 3D prints. Its functionality depends on the even coating of prints with vaporized alcohol, a process that can be set to specific start and end times, ensuring that your prints come out smooth and polished with consistency and efficacy.
Yes, there are chemicals that can smooth PLA plastic similar to the way acetone smooths ABS. However, ethyl acetate is not ideal for many reasons.
We do not recommend using them because they are poisonous (especially when vaporized), expensive, and difficult to find. Ethyl acetate in particular is a health hazard if inhaled and is highly flammable.
You can smooth the layer lines on 3D prints without using hazardous chemicals with products like PolySmooth.
Abrasive Smoothing Methods
There are other ways to smooth 3D prints, such as tumbling and sandblasting. Tumbling uses different media to give you different results, while sandblasting uses a mixture of different things.
The printing process works better with metal-filled PLA than with regular PLA. However, the results vary depending on the brand of PLA filament used.
3D printing is not always successful when you tumble the object. Vibratory bowls work better than rotary tumblers. Using an actual tumbling media, like steel nails/shot or walnut shells, gives more consistent results.
In general, regular PLA prints tend to soften the layer lines but they are still visible. However, metal and wood-filled PLA filaments usually produce nicer results in a tumbler and the layer lines look smoothed and polished.
Sandblasting can be used to smooth out prints made from PLA. The results you get depend on the media used. Fresh sand usually produces the best results. As with tumbling, you won’t completely remove your lines, but they will be less noticeable.
What is the best way to smooth PLA prints?
It really depends on what you want to do with your finished print. If you want it to look smooth and nice with minimal effort, using XTC-3D resin coating is a good option. However, this will add another layer of material on top of your print. If you plan to paint it afterward, you will lose any small details.
If you want more control over the details on your prints, sanding is the best way to do it. You have more control over where the sandpaper goes when you do it by hand. This method is best for prints that will be painted after they are smoothed.
Another way to smooth your prints quickly and easily is to use PolySmooth filament instead of PLA. This will give you smoother results than using PLA, but it doesn’t take as long as sanding.
How do you smooth PLA without sanding?
To smooth 3D prints without sanding, you can use a liquid coating or filler primer to fill in and seal the layers. XTC-3D and 3D Gloop are the best choices for this, but there are other products available as well.
You can use the heat gun method detailed in this article to smooth your prints, but it can be difficult to do it well and it might not always produce consistent results.
Can you acetone smooth PLA?
No, acetone will not have the same reaction with PLA plastic as it does with ABS. ABS will dissolve in acetone, but PLA will not. This means that using a chemical smoother is not possible for PLA prints.
If you want the experience of printing with PLA and the easy smoothing of acetone, you will need to buy PolySmooth or some other filament made for easy post-processing.
Can you smooth PLA with heat?
You can use heat to smooth your PLA parts, but it is easy to damage your prints this way. The best way to heat smooth 3D prints is to only heat the outside layers of plastic. If you are too aggressive, you will melt or warp the inside layers, causing the print to deform.
Heating your prints in an oven or similar appliance often results in uneven heating. This is because the heat is coming from a static source, so it doesn’t distribute evenly within the oven.
Your results with smoothing PLA in an oven will vary
A heat gun is a better way to heat up your print evenly. Static heat sources produce inconsistent results, but a heat gun gives you more control. However, using an open flame can damage the prints, even if you move them around.
Does isopropyl smooth PLA?
No, IPA will not smooth PLA. However, you can get the desired results with Polymaker’s Polysmooth. This is a special PLA filament that has been treated to be more responsive to IPA if you want to smooth it out.
Can you vapor smooth PLA?
You can use a vapor deposition process to smooth PLA 3D prints, but the chemicals required are not safe for human exposure.
How do you smooth a 3D printed figure?
There are myriad techniques to attain a smooth surface on a 3D printed figure. One possible approach is to employ sandpaper and delicately abrade the jagged edges. Alternatively, a heat gun can be utilized to partially liquefy the edges, imparting a sleeker appearance.
How do I get a smooth finish with PLA?
For those seeking to smoothen the surface of a PLA printed model, a range of options are available. To begin, it is essential to ensure that the printer is precisely calibrated to ensure uniform layering. In addition, using superior-quality PLA filaments can enhance the probability of attaining a polished finish. Finally, experimenting with varied nozzle sizes could be advantageous in achieving an even smoother surface, particularly as smaller nozzle sizes correspond to thinner layer heights.
You have several options for making your PLA prints look great. One way is to use a product that fills in the layer lines and makes the print smooth. Another way is to use a special filament that helps with the smoothing process. You can also use sandpaper to make the prints smoother.