A few days ago I responded to a request for suggestions as to how to 
remove broken bolts from a block.  I described having heard and once seen 
the process of using an electric arc welder to fuse a welding rod to the 
broken end, and using the newly formed single piece to screw the 
remaining bolt end out.
  Well, I just had a chance to ask this expert and practicer of many 
strange and unexpected tricks, just how it's done.  I'll leave out the 
references to pregnant female dogs, their offspring, and sexual acts, but 
my lack of precision in this description is largely due to the fact that 
my source understands, feels and acts in an artful way rather than as a 
calculating engineer.
  He covers the outside of the rod with something nonconductive, some 
thin tubing or even tape will do.  Then he selects some rod that's really 
large for the hole.  He selects an amp range using his AC welder that 
will easily deliver some good "fire."  Then he starts and briefly 
maintains an arc, enough so there's no doubt that he has two molten ends. 
 Next he "sticks" them together, and instantly releases the rod from the 
rod holder by depressing the spring loaded holding clamp.  Then, he bends 
the rod 90 degrees compared to the part that's stuck.  "Now, you have to 
wait for a bit, so the heat will work its way down into the part and 
disturb the frozen surfaces.  Then you just turn it out using the bent 
part of the rod as a handle."  He's done it a lot in the last 40 years, 
and he says those 5.7 liter GM diesels needed it a lot.  He also reports 
that it seems to work better on stuff that's not too small.  
  Well, that's it folks.  I tried to pump for more specific measurable 
descriptors, but that's just not the way he does things.  Hope this adds 
something usable to a stuck persons arsenal.  Lots of us have struggled 
with "easy outs," and the success rate is reported to be better for this 
technique.  Failure will leave the familiar artful drilling etc.
	Good luck,
	John