cracked slant block

The kind of nickel-based rods for this work like Machineman63 referenced melt at low Amps, I used General Alloys EA201 for all kinds of cast repairs & out-welding. A bit
of preheating is a good idea, but You needn't be fussy about that, most of these alloy/special flux rods simply require You to peen the deposit right after You draw off to
stress relieve the area. Brazing and thermo-kinetic or "spray welding" both will work as well. With cast the risk of porosity is always there, but common chemical sealers
will easily put the stop to that if any. Prep is the key to problem free...........