09-09-2016, 01:47 AM
yrs ago when I had my mech shop we used to get a lot of cars/trucks with broken bolts in heads and gearboxes .
we use to get the mig and place a washer with the hole over the broken bolt/stud ect then put a tack weld from the broken bolt to the washer then cool it down and slowly build up the weld from broken stud to washer . once the weld cooled we then put a nut over the weld an weld it on the inside so you could get a spanner/socket on it an slowly unwind it .99percent of the time we could get the broken stud/bolt out an hardly no damage to the thread or the head/gearbox .I still do it that way on some Harleys an jap bikes I work on and have taken 1/4 unc taps that my son broke off in his alloy rocker covers he made for his car
we use to get the mig and place a washer with the hole over the broken bolt/stud ect then put a tack weld from the broken bolt to the washer then cool it down and slowly build up the weld from broken stud to washer . once the weld cooled we then put a nut over the weld an weld it on the inside so you could get a spanner/socket on it an slowly unwind it .99percent of the time we could get the broken stud/bolt out an hardly no damage to the thread or the head/gearbox .I still do it that way on some Harleys an jap bikes I work on and have taken 1/4 unc taps that my son broke off in his alloy rocker covers he made for his car