If you’re an engineer or product designer creating concept models, a prop or set designer, artist, or an educator looking to add incorporate a bit more creativity into your classroom 3D printing activities, painting your models can be a great solution.

 

This tutorial will show you how to create a nearly automotive quality paint job on any of your 3D printed objects.

 

Working time will vary depending on your model. Including drying time, this process took about 6 hours from start to finish.

 

Supplies Needed:

- 3D print
- Rubbing alcohol
- Paper towels
- Spray primer/filler
- Spray print
- Hanging cord
- 80, 120, 240, 200, 1000 grit sandpaper
- Needlenose pliers
- Bondo
- Sanding block & sandpaper
- Gloves
- Eye protection
- Respiratory mask

 

Step 1: Prepare & Print Model

 

When preparing models for painting in MakerBot Print, keep in mind how your print settings will affect the quality of your paint job.

 

Consider: Print settings, print orientation, number of build plates

 

Tip:
Surfaces printed in the Z axis will have the smoothest surface finish.

 

Tip:
Printing models in 100 micron layer resolution will result in a slightly smoother surface finish, but will take significantly longer.

 

Tip:
If possible, avoid placing support material in places you intend to paint as they will require more post processing to remove completely.

 

Step 2: Remove Support Material & Rafts

 

Supplies used: Needle-nose pliers or flush cutters

 

After you remove your print from the build plate of your printer, you will need to remove any raft or support material.

 

A. Remove prints from the build plate

 

B. Remove rafts

 

C. Remove large pieces of support

 

D. Approach smaller pieces and fine details

 

Step 3: Sand, Glue & User Filler (Optional)

 

Supplies used: Sanding block, electric sander, 80,120, 240, 400, & 1000 grit sandpaper, Cyanoacrylate glue (super glue), Bondo

 

For the highest quality paint surface, an optional next step is to sand your model.

 

Make sure to wear eye protection, gloves, and a respiratory mask.

 

A. Dry sand the model using 80-240 grit sandpaper

 

B. Wet sand the model using 400 & 1000 grit sandpaper

 

C. Glue the parts of your model together

 

D. Apply filler to any gaps or blemish in your model and sand once dry.

 

Step 4: Hang

 

Supplies used: Hanging cord

 

Once your model is ready for painting - hang it in an open, dust free space with plenty of ventilation. This will allow you to paint all surfaces evenly without having to handle the model while paint is drying.

A. Tie hanging cord around the model

 

B. Hang the model in an open room with a tarp

 

Step 5: Primer/Filler

Whether you have chosen to sand your model and apply filler or you are simply painting a rough PLA model printed at high resolution, a few layers of primer/filler will fill any small surface imperfections before painting.

 

Primer filler is a high build spray filler that comes in aerosol form and can be purchased at most local hardware stores.

 

 

Tip:
Before spraying remember to wear gloves, eye protection, and a respiratory mask.

 

Be Sure To:

Shake well before use
Use wide strokes beginning and ending in space outside of the model
Hold the can 10-12 inches from the model
Paint in thin layers using a misting technique

 

Avoid:

Painting in thick layers
Holding the can in any spot for a long time
Holding the can too close to the model

 

Step 6: Allow Model to Dry

Once you’ve sprayed 2-3 layers of primer/filler, allow your model to dry for 30-40 minutes.

 

Step 7: Sand

A. Lightly sand your model with 1000 grit sandpaper (dry). This will smooth the surface of the model as the primer filler tends to create a rough surface texture similar to sandpaper.

 

B. Evaluate for quality.

 

C. If there are still surface imperfections you would like to smooth, continue to apply consecutive layers of primer/filler, and sand.

 

Once you are happy with the model surface, move on to painting.

 

 

Step 8: Paint

When choosing paint, you typically have a large degree of freedom as to which colour and type of paint you use. Make sure to pick something that adheres well to plastic.

 

A. Choose a paint

 

 

B. Test for colour in an inconspicuous location before painting the entire model

 

C. Let the paint sit overnight to cure

 

 

Tip:
Typically, the paint will be dry to touch within an hour or so, and ready to polish within 24-48 hours.

 

Tip:
If you’d like to protect the surface of your painted model, you can also apply a thin clear coat at this point.

 

Final Product:

In the end, you’re left with a beautiful painted model ready for approval presentation, enhanced for sets or galleries, optimized for better classroom learning, or simply improved for better innovation.

 

Here you can see just how far we have come.