Our roof has these wooden support beams which are a pretty rough cut wood, I was wondering which electrical sanding tool would be the best for something like this, an orbital sander, belt sander...? Thanks!
Unless they are going for a distressed finished look, this is a horrible idea. Even with experience there is no way you'll get a flat finish; without experience you'll have deep pockets and very uneven, rounded corners. Maybe slightly faster than a belt sander, but it'd be negligible and definitely not after all the finish sanding that will be required after.