Sharpen up your knife throwing skills, more respectfully known as Impalement Arts, at the Diablo Rod & Gun Club in Concord. The next class is on July 23 and not limited to pitching knives. You will improve your accuracy in throwing tomahawks, screw drivers, shovels and various other devices. $2 fee. The Club also offers instruction in trick roping, pistol fast draw, pistol twirling and whip-cracking.