When rebuilding a worn component to size, remember that for applications subject to high compressive loads, the final hard surfacing must be adequately supported by a strong build up alloy or added section. Soft materials such as mild steel may collapse under service loads causing premature failure of the surfacing by spalling.

The use of copper chill bars can assist in drawing excessive heat from thin edges or in maintaining satisfactory edge build up contours.

Buckets and shovels should receive chequerwork in clay areas, dot technique or chequerwork in straight quarry work as illustrated. While this book deals mainly with arc welding, the oxyacetylene or air propane methods of hard surfacing should not be overlooked, particularly when considering very thin deposits on small sections. The greater heat control with these processes can then be used to advantage.

Finally, if you value your time the cost of the electrodes (within reason) should not be a major criterion for selection.

Hard surfacing underside and leading edge of shares and tines maintains shape and self sharpening action. Lay on copper chill bars to assist surfacing right to edge using Abrasocord 43 or Abrasocord 700. Grind clean the areas to be surfaced and finish grind on edges and to remove high spots.

For Water Boring and similar drill bits, forge or rebuild to shape using preheat 250°C, buffer layer Austarc 16TC and buildup of Abrasocord 350. Surface chisel point with two or three (max.) layers of Abrascord 700 and reaming edges with Abrasocord 43.

For post hole augers use Abrascord 700 on the blade, Abrasocord 43 for edge and top of flight. Use jig to rotate auger at angle for welding in flat position. Use same approach on all screw type conveyors surfacing wearing face of flights

Repoint badly worn teeth with new section with double vee preparation to ensure full penetration butt weld. Use Austarc 16TC on carbon steel teeth, Abrascord 309 on austenitic manganese teeth. Hard surface all round as shown with Abrasocord 10 or Abrasocord 43 for quarry work, top face and sides only with Abrascord 43 for clay operation to ensure self sharpening.

Rebuild badly worn areas with Abrasocord 350 on carbon steel components, Abrascord Mn‑Ni for Aust. Mn. steel sections (nonmagnetic).