Painting your 3D printed parts can be a surprisingly easy process, capable of transforming rough prototypes into presentation ready parts. Product designers, artists, engineers, and hobbyist all benefit from spicing up their prints with a bit of color.
Painting parts may seem daunting to some and the spray painting process can seem crude to others. The technique we’ll be showing you today is surprisingly easy and can produce professional quality results to elevate your designs to the next level. In this tutorial, we will paint the Destiny Ghost designed by Adrian Tanner that we printed on the Formlabs Form 2 3D Printer.
Gather Your Materials
There are a few different things you’re going to need to get started with painting your parts:
3D printing materials vary significantly in their material properties, and a primer will give us a base to do the rest of our painting on. Primers are designed to stick to a large number of materials and serve as a coat for paint to stick to later. Choose a primer that specifies compatibility with plastics.
For parts with rough surface finishes, sanding is an important step to smooth out deformities prior to painting. Bumps that remain after painting require additional sanding and re-application of primer and paint afterwards.
Tack Cloth (optional)
After sanding, a tack cloth will help to remove any dust from the surface. You want to avoid using oils or other compounds after sanding as they inhibit paint from sticking.
Painter’s Tape is designed to adhere firmly to surfaces but remove cleanly without leaving residue behind. We’ll use this to mask areas of our part.
Choosing the right spray paint for your application can be a daunting task. If you’ve used a plastics primer, most standard spray paints will be compatible. We recommend Tamiya Spray Paints which are designed to perform well with plastics and come in a variety of different colors and finishes.
Preparing your part
We’ll get started by removing any surface imperfections from the 3D printed part. Carefully sand down imperfections in your part prior to painting as any defects will be highlighted after you’ve finished painting.
Starting with a coarse 80 grit sandpaper and moving to higher grits can be helpful for speeding up the sanding process. Remove any large imperfections with 80-100 grit sandpaper and then smooth out finer imperfections with 180-200 grit sandpaper. Using finer grits than 200 is often unnecessary with painting as the primer will help to improve your parts surface finish.
After sanding, run a tack cloth over your part to remove dust from sanding. Err away from using compounds like mineral oil to improve your parts surface finish as these inhibit the paint from sticking.
Plastics vary significantly in their material properties and are notoriously challenging to find compatible paints for. We’ll be using a primer designed specifically for plastics, to serve as a base layer for our paint.
We’ll be using the Rustoleum Grey Primer as the base coat for our test part which is a Destiny Ghost designed by Adrian Tanner. Many people choose to use a primer to improve the surface finish and aesthetic of their part without doing any additional painting afterwards.
When designing and printing your part, you’ll want to keep in mind how the part is going to be oriented for painting. Adding a small hole to accommodate a dowel allows you to hold and rotate your part freely while painting.
For most paints, the best technique is to sweep across your part with quick and rapid bursts. This keeps paint from building up in certain areas and dripping. Multiple thin coats provide the best surface finish so don’t worry if your first layer of primer is sparse. Allow your primer to dry before adding additional layers. For most primers, 2 layers is sufficient for a clean surface finish but check your paint for specific instructions.
Before starting with painting, make a plan for what you want the final color scheme of your part to be. Our Destiny Ghost will be Grey with Black accents for the stripes. For this, we’ll start by painting the entire ghost Black and then the Grey will be added afterwards.
We’ll use the same techniques for painting as we did for priming. Coat your part using short bursts of paint making sure to move rapidly across the part. You want to avoid staying in one area as this will cause paint to build up and drip. Use 2-3 sparse coats of paint or continue until your part is fully coated with a smooth surface finish.
Masking is the process by which areas of the part are selectively covered to create patterns or highlight features. Negative features are easier to mask than positive features so we did the stripes first because they’re embossed into the Destiny Ghost model.
To create a mask, apply a strip of painter’s tape over a large section of the feature you’re looking to mask. Use a hard object like a credit card to force the tape into the creases of your part. Next, take a sharp blade and slowly cut along the crease making sure to apply only as much pressure as is needed. Applying too much force can cut into the paint below. Lastly, peel away the tape on the outside of your mask and repeat for as many sections as is needed.
Painting Pt. 2
Our final step is to go over the part with our grey paint. Use the same techniques as listed above to fully coat your part using several light coatings. Don’t worry about coating your mask as the tape will prevent any paint from seeping through. After your paint has fully dried, peel away the mask to reveal your finished part.
Some users will opt to use a clear coat after this step to seal their part and protect it from wear. Clear coats can also be used to add a variety of finishes from glossy to matte. The technique for applying clear coats is generally the same as each of the other paints with several light coats being optimal.
To wrap things up, we’ll provide a quick list of each of these steps for you to reference when painting your own parts:
- Sand down any surface imperfections working your way up to 200 grit
- Use a tack cloth to remove sanding dust from your part
- Apply a primer by spraying across your part in rapid thin coats. Use multiple layers allowing the primer to dry in between.
- Determine the different colors your part will use and plan out the masks
- Apply your base color using multiple thin coats of paint
- Mask your part by applying large strips of painter’s tape and lightly cut away extraneous tape with a sharp blade
- Coat your part in the next paint color
- Allow to fully dry and remove the mask
- Repeat steps 5 – 8 as many times as is required
- Optional: Seal your part in a clear coat for increased wear resistance or to change the surface finish.
That’s all there is to it! We hope this tutorial helps you to add some flare to your printed parts and we’re looking forward to seeing your results.