3D Printing, Applications

How to Finish a 3D Printed Part to Look Like a Production Part

By TriMech on October 4, 2017

Painting and finishing can transform your 3D printed parts to be more aesthetically pleasing, giving them appearance of production parts. Prototypes, concept models and end-use parts can all be finished to presentation-quality in a matter of hours. Our blog outlines how to finish a 3D printed part to look like a production part in four main steps: 1) Preparation, 2) Sanding, 3) Priming and 4) Painting.

Unfinished Part

See our sample part below, which was 3D printed in ABS-M30 plastic at 0.010” layer resolution on a Fortus 250mc printer. It is fresh off the printer, so it still has support material on it (which is white).

Unfinished Part

4 Steps to Finishing Part

Step 1: Prepare

Preparation is the first step to any finishing process. Start by removing support material. This can either be done by hand or by dissolving it away if necessary. Rinse part thoroughly in warm water until the part is clean.

Cleaned Part Without Support Material

Step 2: Sand

Next, sand the areas of the part that will be painted. Start with a rough sandpaper like 150 or 220 grit. Once most of the layer lines have been smoothed out, move to a 300 to 400 grit sandpaper. Keep in mind starting off with a part printed at 0.007” or 0.005” layer resolution will be a smoother part requiring less sanding. On the other hand, you can print a part much faster at 0.013” layers (if your machine allows), but the larger layer height will require more preparation to get smooth. Once sanded thoroughly with a 300-400 grit sandpaper, wash the part with warm water to remove any dust from sanding and allow to completely dry.

Step 3: Prime

After sanding, hang the part in a well-ventilated area. Use a “high-fill” sandable primer. Apply several light coats, allowing for the appropriate amount of time in between coats as directed by the can. Once fully covered in primer, inspect the part. If striations are still visible, go back to sanding. An 800 grit sandpaper is good for smoothing primer. If there are any large irregularities in the surface that can’t be sanded out, use a modeling sanding putty like Tamiya Putty or Squadron Green Putty to fill in gaps, let dry and sand smooth. Re-coat with primer if sanding putty was used or too much primer was sanded off.

Step 4: Paint

With the part still hanging in a well-ventilated area, coat it with several layers of paint. Canned spray paint or paint from a spray gun can be used to paint 3D printed parts. Allow for appropriate time between coats. Inspect the surface of the part to make sure you have 100% paint coverage where you need it. Apply several coats of clear enamel gloss to add shine, protection and a deeper contrast to the part’s appearance. Allow to fully dry about 24 hours before handling.

Watch this video to see these steps in action:

 

Want to learn abotu more 3D printing applications like post processing? Browse our library of blogs by clicking the link below.

Learn More