Hand Sanding and Polishing for PolyJet 3D Printed Parts

Sanding and polishing 3D prints can be tricky. This tutorial demonstrates how to handle post-processing for printed parts when using the Stratasys J750.

  1. Step 1: Overview

    The Stratasys J750 offers appearance capabilities that are relatively advanced in the world of 3D printing. To fully realize the appearance of a printed part or mimic an injection molded part, sanding and polishing by hand is recommended.

    Featured in the picture is a stick shift with a combination of a few colors and surface appearances, all achieved in one print: 

    • Wood grain texture
    • Simulated leather over-wrap with stitched binding 
    • A mock color LCD screen featuring a VeroClear screen surface

    Learn how to polish only the LCD screen and wood grain to produce a more realistic finish – without the need for a lacquer application.

  2. Step 2: Gather Your Materials

    Straight off the printer, the part featured the following matte finish:

    To polish this part, assemble the following grades of waterproof sandpaper:  400, 800, 1000, 1200, 1500, 2000, 2500, 3000.

    You will also need:

    • Turtle Wax polishing compound
    • Silicone Spray
  3. Step 3: Sand Using Varying Grades

    Beginning with 400, carefully sand the screen and wood surface in even, circular motions, being careful to avoid harsh sanding over a single spot that can remove the surface texture layer altogether. 

    Avoid sanding onto the leather texture, but try to get as close to the boundary line as possible – use small circular motions up to the boundary line rather than lateral strokes which can leave unwanted scratch marks (see image):

    Spend 10-20 minutes per sandpaper grade – ideally using wet sanding – with regular rinsing of the paper and part to prevent particles from accumulating and scratching the surface. This becomes more important as you progress to the finer sanding grades. 

    Move on to the next sanding grade when the surface of the part feels completely smooth and gives little "sticking" or resistance to the paper.

    Note: The part surfaces will remain matte until the very last sandpaper grades – 2500 or 3000. 

    Finally, use a Turtle Wax polishing compound (light to medium cleaner) with a soft cloth to remove and even out remaining micro scratches. Scrub the LCD screen and wood grain vigorously with circular motions until the part begins to exhibit a gloss shine and full transparency of the LCD screen (see image):

  4. Step 4: Optional Finishing Touches

    Once you've sanded the part to achieve the polished look you desire, there are still several different finishing options you can employ:

    • Apply a silicone spray to the leather texture to improve the evenness of the leather effect.  
    • Sand the white base of the gear stick lightly with each sandpaper grade – to give a more finished look to the base.  

    If you'd like to learn more about the Stratasys J750 printer or how to achieve multi-colored and textured effects for your workplace, sign up to get more information here.

    Hope this helps! We'd love to see you comment if you used this method and hear about how it worked out for you.