Thanks for all the helpful suggestions. I've been holding the maul perpendicular to my forearm, as I seen other folks do, but I'm trying to hit the stamp, rather than just using the maul's weight. I've broken my marble stone twice so perhaps I'm hitting it too hard?
Perhaps someone could show their foil hats so I can make one correctly. Is it like the hat the guy on Monty Python, whose brain hurts, wears?
SkipJ