How well do monitor arms work with glass computer desks? I want to get an adjustable arm to bring the monitor closer when gaming or other scenarios. If I just get some rubber to make sure any metal parts touch will this work?
Way too many factors to say when it becomes dangerous. For example, the distance is the monitor away from the mount - the longer the distance from its center point, the greater the torque applied to the desk from the mount. What you could do I think is to get some plywood and put above and below where you mount the arm - such that the force applied by the mount on the tabletop is disturbed and not focused onto one area.
I think Vega used a monitor arm with a glass desk for awhile. There might be some pics in his latest build thread, actually.
As long as you aren't clamping down on the glass with needle-sized points, I don't think you'll have any issues. Glass desks are a lot stronger than most people think.
I'd be very careful with it, those 13lbs + arm weight get significantly more in terms of forces when the arm is moved forward much like the lever-effect.
Also, why would you need an arm to move the screen closer towards you?
Been contemplating on getting a larger monitor to play a couple games with. Being able to get the monitor closer to me, I will not have too. These particular games use my pc 360 controller and I feel better about sitting back in my chair and when using a monitor arm at work I find that moving the screen closer and higher so I am almost glancing upwards is helping. Because I can rest my head on the back of my chair by doing this.
It mostly boils down to being able to tilt/pull the monitor forward. Since the keyboard is in the way at the moment, I presently can not do this.
I would be afraid of the arm slipping and crashing the monitor into the glass. Plus if it slides at all your going to have a huge gash in your glass or worse... shattering. If you can, I'd recommend wall mounting. I just did it with 3 23" in eyefinity and it turned out perfect, just make sure to hit the studs.