There are many reasons to coat and paint FDM parts. Whether it’s for UV protection, sealing, or just to make them aesthetically pleasing, painting can bring a product to life. In this tutorial, we will give you steps and tips on how to paint your FDM model.
The following is a tutorial taken from Stratasys’ YouTube channel:
Start by removing any support structures on your print. This can be done using your hand or a tool that can get into crevices. If your part has soluble supports, rinse thoroughly in tap water to clean the part. Then, let your part dry.
Once dry, prepare your surfaces by lightly sanding with a 220-Grit sandpaper. Remove any dust or debris using a small towel or cloth.
Step 3: Optional Step
An optional step is solvent smoothing. Solvent smoothing can reduce the amount of sanding time. If you are working with an ABS or ASA part, you can either dip it in a methylene chloride solution, such as IPS Weld-On 4, or vape smooth it in a Finishing Touch Smoothing Station.
Now it’s time to fill the voids between extrusion path layers with a filler. A light coating of fast drying primer fills small voids and reveal minor imperfections. This may add some time, but by doing this, it draws attention to areas that need additional sanding or filling.
Once the primer is dry and areas that need to be filled are indicated, spread a filler to cover depressions. We recommend using a 3M Acryl-Green Spot Putty as a filler. Avoid applying thick coats. Once the filler is dry, inspect the part for areas that need additional filler.
Next, sand all surfaces using 220-Grit sandpaper until they are visibly smooth. Then sand all surfaces with 320- to 400-Grit sandpaper. Be careful not to alter the part when sanding.
Using a degreaser, remove dirt, oil, and dust (recommended: PPG Acrylic-Clean DX330).
Now it is time to pick your method of painting. Spray painting is easy and with the right ventilated area, can be done by anyone. Make sure it is a good quality enamel paint. Thin coats and steady sweeps of paint are key.
Start by spraying a light coat of primer on the part. Let the primer dry for two to four hours. Apply a second coat of primer and allow that to dry.
Once the primer is dry, sand the part.
If the part requires a matte or textured finish, sand with 320- to 400- Grit wet/dry sandpaper.
If the part requires a glossy finish, start with a 320- to 400- Grit wet/dry sandpaper and then move to a 600- to 800- Grit wet/dry sandpaper.
Using a degreaser, remove any dust or debris. Once the part is dry, it is time to paint. Apply the first coat of paint and allow to dry for 15 to 45 minutes. Then apply second coat. Repeat as necessary.
Important: if you are using multiple colors on a model, it is important to use the same brand of paint for all colors.
Once the desired amount of paint is dry, apply a clear coat to protect the painted finish.
Step 13: Conclusion
Whether it's for aesthetic purposes or for protection, painting an FDM printed part is quite simple. Following the correct painting procedures helps to keep the paint from chipping or fading and ensures that you are not damaging your part in the process.