3D printed panels have layer lines and need some sanding in order to achieve a smooth surface finish.

When sanding your parts, you want to pay attention to the right technique.  This will save time and get the best result.
Sanding the wrong way will ruin your finish or cost a lot of time..

Following steps are recommended:

  1. Dry sand the 3d printed part with 180 grit
  2. Apply a filler / primer (Grundierfueller) base coat
  3. Overspray lightly with any color paint
  4. Wet sand until the overspray is gone (grit 400 – 600)

This article focuses on the dry sanding or the raw 3d print.

Below are some guidelines if you’re not familiar with model making techniques.

What you need

  • your fantastic 3d print
  • some background music
  • Sandpaper, 180 grit works well at this stage
  • a small tool to keep you sandpaper in shape

Use a sanding Block

First of all: don’t sand a rough surface with your bare hand. Not only is it slow, but you also risk making uneven spots worse instead of better.

Always wrap your sandpaper around a fixed shape, like a small piece of wood or plastic.  This way you’ll have control over the outcome, and it is much quicker. For very round shapes, use a more flexible support tool, like a piece of rubber or cork.

A support tool ensures that you sand only on the high spots when you have an uneven surface. This way you’ll even out the surface in a controlled way.

Follow the curvature

When sanding a curved area, your sanding movements should follow the curvature of the object. This way you’ll keep the shape intact.

If you sand against the curvature, you will create a flat spot!  Flat spots will be visible in the reflections when the part is painted.

Sand away from the edges

Try to stay on the flat surfaces while sanding, and don’t sand over the edges, otherwise the geometry will lose its definition.

Don’t inhale the dust

Have you heard the saying ‘sanding 3d printed CY sidepanels is the new smoking’ ?

Me neither.

Nonetheless, your lungs aren’t the best place to store fine plastic dust from sanding. Work outside if you can and wear a dust mask.