I picked up an 80lb piece of railroad rail that's about 2 1/2 feet long. I'm trying to decide if I should mount it vertically and use the cross section of the rail as my surface or use it horizontally. As rail goes, the top of the track (the hard surface) is not too badly radiused and one edge is pretty straight and sharp. But still a bit radiused. Vertically, in cross section, it has a very flat surface with nice sharp edges, but it is only 3"x2". And it would have the advantage of more mass beneath it since I wouldn't be pounding over the webbing. I know that you don't need a ton of area to work on... but is 3x2 TOO small for anything other than tiny blades???