Do you want to start smoothing a 3D print but don’t know how to do it? At Imprimy.com, we’re here to explain everything to you.
How to properly prepare a 3D print before smoothing?
To properly prepare a 3D print before smoothing, you should start by selecting the right print quality, then perform deburring and an initial sanding.
Choosing the right print quality from the start
To achieve a high-quality 3D print and minimize defects requiring post-processing, it is essential to properly configure your printer from the start. Choose a layer height suited to your project: a low height (0.1 mm) provides a more detailed finish, while a higher height (0.2-0.3 mm) speeds up printing at the cost of finer layers.
Also, ensure you use a moderate printing speed to avoid vibrations and maintain a consistent filament extrusion. Selecting the right infill—typically between 15% and 25% for a balance between strength and material consumption—along with proper bed and extruder calibration, are key factors in preventing visible defects and achieving optimal results straight from the printer.
Deburring and Initial Sanding
Deburring and Initial Sanding are essential steps to improve the finish of a 3D print by removing visible imperfections. First, carefully remove supports and excess material using a precision cutter or flush cutters, making sure not to damage the piece.
Next, perform progressive sanding with coarse-grit sandpaper (120-200) to smooth out the most pronounced layer lines. It is recommended to sand in circular motions and adjust the pressure based on the fragility of the part. This initial phase effectively prepares the surface for further finishing steps, such as fine sanding, applying a primer, or adding a coating.
What smoothing methods should be used depending on the materials?
Some specific 3D print smoothing methods, such as mechanical smoothing and chemical smoothing, can be applied depending on the materials you used for your 3D prints.
Mechanical smoothing
Mechanical smoothing of a 3D print involves using abrasive tools, such as sandpaper, files, or rotary discs, to remove the striations left by layer-by-layer printing. You can start with a coarse grit (around 100-200) to remove major irregularities, then gradually refine with finer grits (400-1000) to achieve a smooth surface.
Using a vibrating sander or a Dremel can speed up the process, but care should be taken to avoid overheating or damaging the piece. For optimal results, you can then apply a primer and wet-sand with a very fine grit before painting or varnishing.
Chemical smoothing
Chemical smoothing of a 3D print involves exposing the piece to vapors or liquid solvents that react with its surface, slightly melting it to remove the printing striations. This method is particularly effective for materials such as:
- ABS, which can be smoothed using acetone
- PLA, which reacts with tetrahydrofuran or other specific solvents.
You can suspend the piece in an airtight container containing the solvent in vapor form, making sure to carefully control the exposure to avoid any deformation. It is also possible to apply the solvent with a brush or a cloth soaked in it, although this approach is less uniform.
This technique requires precautions, including proper protective equipment and adequate ventilation, due to the toxic fumes from the solvents used.
What are the other existing methods?
Other existing 3D print smoothing methods include applying putty or adding a primer coat followed by painting on your 3D printed piece.
The application of putty
The application of putty is an effective solution for smoothing a 3D print by filling in striations and imperfections before finishing. You can use a spray putty, like a filling primer, or a paste putty, such as polyester or epoxy putty, applied with a spatula. After application, it is important to let it dry completely before sanding with medium-grit sandpaper, then fine-grit, to achieve a smooth surface.
This method is particularly useful for prints with large irregularities or those requiring a perfectly smooth finish before painting. For optimal results, it is recommended to apply several thin layers rather than a single thick layer, to avoid overloading and better control the smoothing process.
The primer coat and painting
The application of a primer coat and painting is an essential step to perfect the smoothing of a 3D print and achieve an aesthetic and durable finish. Applying a primer coat helps to even out the surface, reveal any imperfections, and improve paint adhesion. It is recommended to apply several thin layers, lightly sanding between each coat with fine-grit sandpaper (600-1000) for a perfectly smooth result.
Once the primer is fully dry, you can apply the paint in several thin and even layers, preferably using spray paint to avoid brush marks. Finally, to protect and enhance the result, a finish with a matte, satin, or glossy varnish can be added, ensuring better resistance to scratches and wear.
Conclusion: Smoothing a 3D Print
Smoothing a 3D print is a crucial step in improving the appearance and texture of your printed object. Whether you choose mechanical smoothing, chemical smoothing, putty application, or a primer and paint finish, each method offers distinct advantages depending on the material and desired result. By carefully selecting the appropriate technique, such as sanding, using solvents, or applying coatings, you can achieve a smooth, professional-quality surface. For optimal results, a combination of methods—such as using putty followed by a primer and paint—can further enhance the finish. Ultimately, smoothing not only improves the aesthetic appeal of the print but also increases its durability and functionality.
Picture by Freepik.
The articles published on Imprimy.com are for informational purposes only. They are intended to provide general advice and information related to 3D printing. Imprimy.com cannot be held responsible for the results obtained or the consequences arising from the application of the shared information. We recommend always checking the specific instructions for your hardware and materials before use.
