Finishing 3D printed parts

Very visible layer lines on these UFO models

3D printing leaves a clear layering pattern on finished parts due to how the models are constructed. This layering is sometimes not acceptable aesthetically for finished parts, so what can you do?

Printing at 0.1mm leaves much smaller layers than printing at 0.3mm. These smaller layers have smaller ridges, and will make all of the following steps go so much faster. if a nice smooth finish is your goal, take the extra time and print at as low a layer height as you can.

Next, you need to actually get rid of the ridges. You can either sand the ridges down or build up some other material over them. I’ve had much better luck with the latter approach. I’ve used XTC-3D with some success, although it takes hours to days to cure fully and it’s easy to overdo it. Use several light coats instead of one large one, and set the part aside for several days before use or painting.

Bottom of Cobra

I’ve also had some pretty good results just using regular primer and sandpaper. The Elite: Dangerous Cobra model here was printed at 0.1mm and:

• Primed with regular black spray primer (lightly)
• Sanded with 150 grit sandpaper
• Another layer of primer
• Sanded with 150 and 400 grit
• Another layer of primer
• Sanded with 400 and 800 grit sandpaper

As you can see, the layer lines are all but gone, although the surface is still somewhat textured. I could have gone up to 1500 grit sandpaper for an incredibly smooth finish but that would have been overkill for this project.

Finished “onionhead” paint job – top of Cobra

I then finished up the model with some miniatures paints, which I am admittedly not very skilled at.