Sanding and finishing of parts
To make the surfaces of a print off the J850 glossy, some post-processing work must be done in the form of sanding and polishing
Before and after sanding and polishing
1. Sanding
Wet sanding with different grits (aggressiveness) of sandpaper will be done. We will start with the coarsest (most aggressive) and work towards the least aggressive
The lower the grit number, the more material the sandpaper will remove
Depending on the amount of material you will either start with 180-grit or 220-grit sandpaper. The first step is to wet the sandpaper with water
If you are sanding one of the dice or something else with a thin outer layer of material/color, you need to be careful not to remove too much material or the dots will disappear, so start with 220-grit in that case
Sand each face that you would like to have a glossy finish on, sanding each side for a few seconds, and potentially the corners.
Once done with the first sandpaper, move up to the next least aggressive grit
The order of grits is 180 -> 220 -> 400 -> 600 -> 800 -> 1000 -> 1200 -> 1500 -> 2000 -> 3000
Do not skip any of the grits in the process or the small scratches from the previous grit might not be removed, leaving the end result not glossy
Do not forget to use the 3000 grit sandpaper even though it looks different. It must also be watered before use.
Ensure to rinse off all of the sandpapers that you used afterwards to remove any debris from the sanding process. Lay the sandpaper out to dry
Note that the part surface will not be perfectly glossy by the end of the sanding process
2. Polishing
Begin by turning on the buffer using the power button. Then press the 900 button
The buffing wheel on both sides should begin to rotate
Next we will add some buffing compound to the wheel. To do this, select the blue/purple bar and hold it up to the edge of the wheel as shown. You should do this for 5 to 10 seconds
Note that there should not be any color change on the buffing wheel while adding the buffing compound
Next begin to polish your object by applying light pressure initially against the wheel edge with the part. Examine the part frequently as you go to ensure you only remove as much material as you need to
Before polishing
After polishing
When finished with the buffing wheel, press the power button to stop the rotation. Once rotation stops, press the power button again to turn off the machine