I am currently planning a small blacksmith shop, and I would like to build a power hammer of either the Krusty/Rusty or Tire variety (still undecided, I like the simplicity of the Krusty, but the space savings of the tire hammer is a big draw). My question is about the anvil. My idea is to use 36" of 12"x12" square tube with a .5" wall, with a 36" piece of 1.5" 1045 bar centered and then filled with aluminum and capped with a .5" plate. By my calculations, the overall weight would be roughly 676 lbs (228 for tube, 18 for the bar, 20 for the plate, and 410 for the aluminum) which would allow me to use a 30 lb hammer and still maintain a little better than 20:1 ratio. So do you fine gentlemen think this would work?
The idea of the bar in the center is to help absorb some of the force and better distribute it throughout the depth, I was worried that the aluminum alone under the plate would possibly deform with heavy use. The main use for the hammer will be larger tools and eventually pattern welding as well.