Carton 100mm f/13 "MD" OTA Construction - Preparing the Main Tube - Sanding (Medium Grit)
 

Medium grit sanding of the main tube. (Click to see an enlarged image)

 
With the arms getting a good workout, I moved to a medium grit sandpaper. In this case, a 220-grit sanding disk for my random orbital sander. I did the sanding by hand and not with the ROS. This effort produced a smooth brushed patina to the surface of the aluminum main tube. Quite a comparison to the previous coarse grit appearance. Well, there's more work to do... So I better get to it.