Sorbothane record weight?

I have an older b&o rx2 turntable that I am not comfortable putting much weight on, the spindle will probably not work with a clamp, and the tone arm is not adjustable so I am not interested in adding a mat.  It occurred to me that maybe a "puck" that doesn't weigh much could be made out of layers of sorbothane sheets and used as a low mass "weight" to damp record vibrations.  I have googled and searched forums and haven't found any hint that anyone has tried this. 

Is this a really bad idea for some reason I cannot think of?  I am certainly no expert.

Steve