Due to the nature of most 3D printing technologies, printed parts are rarely perfect immediately after printing. Surfaces may appear rough, support structures are often present, and additional finishing is usually required.
That is why proper post-processing is an essential step in achieving a functional and visually refined final product.
Below are the most commonly used surface finishing methods.
Support Removal
Supports prevent parts from collapsing during the printing process. After printing, they must be removed.
If supports are located in hard-to-reach areas, removal can be challenging. Some support materials are dissolvable and can be removed chemically. Non-soluble supports must be removed manually, typically using tools such as pliers.
Advantages:
- Simplest form of post-processing
- Requires minimal equipment
Disadvantages:
- Risk of damaging the printed part during removal
- Surface areas where supports were attached must be smoothed afterward
Sanding
Sanding is the most common finishing method. It is typically performed using sandpaper of varying grit levels. Professional workshops often use small electric sanders. The process usually starts with lower grit and progresses to finer grit for smoothing.
Advantages:
- Requires only basic tools
- Even very rough prints can be smoothed
- Low cost
Disadvantages:
- Time-consuming and labor-intensive
- Manual sanding may be uneven
- Some areas may be difficult to access
- Should be performed in a workshop or controlled environment
Acetone Smoothing
The printed part is placed inside a sealed container and exposed to acetone vapor. The vapor reacts with the outer surface layer, slightly melting it and creating a smooth, glossy finish.
Advantages:
- Glossy surface appearance
- Relatively low cost
- Fast and simple process
Disadvantages:
- Suitable only for ABS materials
- Acetone is toxic and requires careful handling
- Difficult to precisely control material removal; therefore, professional companies often avoid this method
Painting
Before painting, the print should ideally be sanded. A primer coat is first applied to prepare the surface. Once dry, the final color can be applied using a brush or spray.
Advantages:
- Enhances product appearance and perceived quality
- Creates a smooth surface
- Allows multi-color finishes
Disadvantages:
- Relatively time-intensive
- Requires skill to achieve a uniform surface
- Should be performed in well-ventilated areas
Polishing
Polishing a sanded 3D print can achieve a high-gloss surface finish.
Advantages:
- Straightforward process using electric tools
Disadvantages:
- Fine particles may be released and inhaled
- Must be performed in a workshop using protective equipment
- Requires skill and caution
Electroplating
Electroplating provides a metallic appearance and enhances structural properties. Common metals used include copper, chrome, silver, nickel, and gold.
Advantages:
- Real metallic look and feel
- Improved structural strength
Disadvantages:
- Only certain materials (e.g., ABS) are suitable
- Complex and costly process
- Requires specialized equipment
Bonding
Multiple printed parts can be glued together to form a final product. This is common for larger components that exceed the printer’s build volume.
Advantages:
- Strong bond between parts
- Relatively simple and cost-effective
Disadvantages:
- Bonded parts are never as strong as a single-piece print
- Mechanical and physical properties may be affected
Cold Welding
Cold welding joins two ABS parts using acetone. The acetone partially dissolves the material, allowing a uniform bond to form. The larger the bonding surface, the stronger the joint.
Advantages:
- Creates strong joints
- Relatively inexpensive and simple
Disadvantages:
- Applicable only to ABS materials
- Bonded parts are never as strong as a single-piece print
Gap Filling
After sanding or removing dissolvable supports, gaps or surface imperfections may appear. These must be manually filled. Professionals typically use the same material as the original print for filling.
Advantages:
- Eliminates gaps and surface defects
Disadvantages:
- Requires additional sanding to achieve a smooth finish
Proper post-processing is what transforms a raw 3D print into a functional, professional-grade product.
Do not hesitate to collaborate with 3D printing specialists who can provide complete solutions — from printing to surface finishing and, if needed, integration with other manufacturing technologies.
We would be happy to discuss the most suitable finishing methods for your project in our showroom or remotely.
Contact us to achieve the highest quality for your 3D printed products.
