I have a request to build a gong out of 1/4 plate. Maybe 3 or 4 feet in diameter. Any clues onto how I can make it convex? I don't have a forge yet but if this project requires one, why not build one. I do have a set of ace/oxy torches. I was thinking of heating it with a torch and then sledge hammering it into the dirt. I would carve a bowl out of the dirt. please help me guys. much thanks greg