I have seen many options concerning conduit, has anyone tried sanding/polishing conduit? painting or coating conduit? I would love your thoughts. I am planning on using the standard but want to consider all options and I know there have to be others who have tried something different.i intend to build a machine 18 x 18 (28.4 x 28.4). how much benefit will you really gain from options other than standard?

Unless they did a really crappy job on the galvanizing, I wouldn’t worry about sanding. The small amount of roughness isn’t going to cause an issue. It may flake off some, but that’s about it. Paint will flake under the bearings, which will look bad after a while.