Finishing a 3D-printed part: ABS smoothing and coloring without chemicals

When printing with a FDM printer, such as our Solidoodle, the surface becomes kind of “liny”. We use this priniting technology to create different system parts, where surface appearance is not of importance. But what to do if you want a smooth part?

ABS can be treated with Acetone. The Acetone chemically melts the plastic, so yes, details will/can be lost. A common method is to give the part a Acetone vapor bath treatment, which will result in a (hopefully) supersmooth part, looking a lot like an injection molded one.

But there exist at least one other method to smooth out the surface: Sanding.

If you sand and plaster the part, you also need to coat it to hide the filler. Compared to the Acetone process this concists of at least three steps:

  1. Applying filler
  2. Sanding
  3. Painting

And sanding can be really difficult on complex surfaces!

I’m finishing something that is pretty simple to sand: the Havtek logo.

Printed logo
Printed logo

Yes, I printed the logo on a pretty uncalibrated machine. But since this part was going to be sanded, that didn’t matter..

Sanding before applying filler
Sanding before applying filler
Applying filler
Applying filler

Spray-filler will be used next time. Less messy..

Sanding
Sanding
Sanding
Sanding
Spraying
Spraying

The trick with applying spray paint is to be patient. Apply many thin layers. I was kind of impatient, resulting in some roughness in the paint, which I had to sand down before applying more paint =/

Roughness in the paint job
Roughness in the paint job

The paint cloud coming out of the spray I used consisted of fairly large drops, resulting in a kind of rough surface. But that’s cool:)

Finished logo
Finished logo

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