Working With Boron-Alloyed Steel– Removal (Air Chisel)
Ever here how an air chisel is for mechanics and nothing more than a crude tool for cutting a hole in a part to gain access? Would you ever use it to remove an exterior body panel from a reinforcement?
Well you should start to consider trying this air chisel technique. In the past, when all the steel was mild steel, this technique would not work because the flanges were soft and would be severely deformed if you tried to use an air chisel to remove spot welds. But with boron-alloyed ultra-high-strength steel (UHSS), if you need to take off a thin outer panel from thicker high-strength steel (HSS) reinforcements, an air chisel will work great.
Think about it, on the flange you can see the different thicknesses and the location of the reinforcements. The reinforcement is so strong that a 10-ton pulling tower has a hard time moving the part. So why would you deform the flange separating a weaker outer body panel?
To remove the outer panel, use a sharp flat chisel, feather the trigger lightly, going about halfway into the spot weld, and then switch to the other side of the spot weld. Care must also be taken to not go to deep by staying in the flange area only. Once you go to the second side of the spot weld it should pop right off, leaving only a small nugget to be dressed.
But don't take my word for it, try it out on a scrap part of a vehicle and see for yourself, you may be pleasantly surprised.
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