Chris,
Nice story about using asphalt for sandpaper. It made me feel a little better about listening to the guy that told me to put a tap in the muffer and crankcase. Supposedly if you put a line between the two it would supercharge the engine. ??? It might have been the same guy you talked to.

Here's my 1/2a prop balancer. Magnets came from happy meal toys and the rod is 1/8 music wire.(I think) To make the points on the end I put the rod in a drill and stuck it to a running bench grinder. The rod seems to be balanced very well. Anyway, it does get my props close enough to eliminate vibration problems.