when welding 1/4" thick or over you need to apply a root weld.Once you have beveled out your metal all the way and cleaned it up,you begin with the root pass this is the main BITE of the weld. You can start outwith an 1/8" rod, BUT to really get true penetration start with a 3/16" rod. the rate of travel depends on your base work thickness.adjust your amp. to at least 200 amp. and weld in a WISP motion and continue filling the bevel with passes ending with the CAP weld.