Sanding
By Gregorio Rios – 3D Modeling
3D printed objects, whether they are ABS or PLA plastic will require a method to smooth out the surface. There will always be visible lines on the surface of the printing objects. These lines on the surface are from the layers of plastic being printed one on top of another. There are different methods for smoothing the surface, but at this time sanding will be our choice.
Before sanding, check for imperfections since printed object will always have small parts that stick out and will have to be removed. Knifes, pliers, scissors and abrasive files will come in handy for the imperfections before sanding. Remove any plastic strings or imperfections that stick out with a small sharp or little scissors.
If there are any bulges on the print, use files to remove these imperfections. Using a Dremel multi tool could also be very useful for grinding, cleaning to remove imperfections and even sanding. Now that the imperfections are gone, now it’s time to get to sanding.
As a precaution use a mask or respirator when sanding. Start by sanding the surface of the 3D printed part with a 100 or 150-grit sand papers (of Dremel wheels) then 220, 320 fine, 500 super fine, and then use a micron-grade grits to erase sanding marks. When sanding the surfaces, do so in a circular motion until it is smooth and flat to the touch. Pay attention to the act of sanding and do not rush just finish sanding the surface. Do not go too fine too fast or you will round over the plastic ridges without actually flattening them.
Use a heat gun after sanding the surface. Gently warm the surface until it melts slightly, which will erase many of the smaller scratches and restore the original printed color.
If you would like to paint it use 3 to 4 coats primer before color paint. Make sure that the primer is completely dry before masking off any undesired parts that you do not want to color. Be sure that the masked edges are firmly taped on and sharp. Start with a light color coat as well as a light sanding (600 grit) between each coat. Spray 3 to 4 more coats of color spray paint (or airbrush) on desired areas.
REFERENCES:
http://edutechwiki.unige.ch/en/Post_processing_of_3D_polymer_prints