Robb Gunter recomends using 3/16 inch stoody 2110 for buildup, and 1/8 inch stoody 1105 for the face. Grind all surfaces to be welded, Preheat the anvil (or whatever chunk of metal you decide to use) to 400-450 degrees. You can put down an unlimited # of layers with the 2110 in order to build up the surface or replace any missing metal. With the 1105 you have to be sure to not exceed 3 layers, so use it sparingly. after welding re heat the anvil to 400 degrees and pack it in vermiculite or wrap it in a welding blanket (anything that will help it to cool verry slowly). Once it has cooled, just grind to shape and your done.
Another way to do it is with Rankin hardfacing wire in a MIG welder. You can use Rankin BB-G for buildup, and Rankin DD-G for hardface. You still have to grind the areas to be welded, preheat, and post-heat, but only to 200 degrees. The wire is a ton faster, but you need to have a machine capable of running .045 wire at 250 amps (Big machine).
If you are planning on welding on rail road track you really should preheat and post heat (or at a minimum slow cool) the chunk of track no mater what filler metal you chose to use. this will help to prevent the underbead cracking that is common when welding on steels with carbon contents higher than .5%  |