I read all of your posts. I do have a problem with being direct because I very often come off abrasive. I'm not good at confrontation.
I am the PhD student who has been in the lab longest. Maddie and I share a bench, and we get along well.
This morning I told Barney I needed to talk to him, and in a calm, quiet voice told him the following:
"Please take your things and move to other bench. I'm asking you to do this for two reasons: one, the bench is becoming very crowded and two, I am not at ease working next to you.
I am still angry about what happened last week. Your behaviour was unprofessional, irresponsible and frankly, rude..."
At this point Barney interjected with "But I apologized for that!"
I continued, in the same calm, quiet voice:
"Actually, no you didn't and please let me finish what I have to say. I don't know what you were thinking when you decided to work in Apparatus when you knew perfectly well I was in the middle of working there. That kind of behaviour is not acceptable in our lab, and cannot repeat itself. You endangered me, yourself and the rest of the people in the lab by not following regulations. If you are unsure of how to work with something, ask someone to help you or to supervise you as you work. Now, please take your things and move to the other bench you will be more comfortable there."
He kept nodding and saying "OK, OK, OK." I normally doubt people actually understand when they reply like that, but here's hoping.
He has been avoiding me all day since. Maddie thinks he is afraid to come near our part of the lab.