opsled
Active member
I've been removing broken off studs and bolts for years with a welder and have always had great success. I usually clean up the broken bolt/stud, weld a washer to it then a nut to the washer. Usually with a mig welder. Most often it works great and with a little back and forth, some light tapping and a penetrant the bolt/stud will screw right out. Some can be buggers but most will give up with good technique and patience.
The new twist I tried the other day was to use a Tig welder instead of a mig. This one was an exhaust manifold stud on an ISM Cummings diesel that had been broken for some time. Steel bolt cast iron block.
The manifold was removed so I could tell by looking at the other bolts that this one was about 3/4" deep into the block and was slightly below flush with rusty threads. The bolt was metric and about 7/16 in diameter. I drilled an 1/8" pilot followed by a 3/16" through the center of the stud. I then took the tig torch with the tungsten extended, shielding gas cranked up and set on about 90 amps to my predrilled hole.
I lit the torch at the stud and pushed the tungsten into the hole enough to really heat and just barely start to melt the stud. I did this three times with a short cooling spell in between. I could visually see the broken stud shrink down and separate from the block. The intense heat from the tig on the stud caused this shrinking and the hole in the center of the stud gave it room to do so. After the final cool I just relit the torch and dabbed the end of the stud with filler rod closing the hole and building it up so I could get a hold of it with a vise grips. Screwed right out super easy.
The heat from a tig is much more intense than that of a mig, stick or gas type torch. You can also pin point the heat with a tig much more accurately than the rest. The high heat, accuracy factor and the ability to add filler only when wanted is so much better.
I've done two more smaller studs in aluminum in the same fashion since with the same results.
My tig torch is not just a welding tool anymore.
opsled
The new twist I tried the other day was to use a Tig welder instead of a mig. This one was an exhaust manifold stud on an ISM Cummings diesel that had been broken for some time. Steel bolt cast iron block.
The manifold was removed so I could tell by looking at the other bolts that this one was about 3/4" deep into the block and was slightly below flush with rusty threads. The bolt was metric and about 7/16 in diameter. I drilled an 1/8" pilot followed by a 3/16" through the center of the stud. I then took the tig torch with the tungsten extended, shielding gas cranked up and set on about 90 amps to my predrilled hole.
I lit the torch at the stud and pushed the tungsten into the hole enough to really heat and just barely start to melt the stud. I did this three times with a short cooling spell in between. I could visually see the broken stud shrink down and separate from the block. The intense heat from the tig on the stud caused this shrinking and the hole in the center of the stud gave it room to do so. After the final cool I just relit the torch and dabbed the end of the stud with filler rod closing the hole and building it up so I could get a hold of it with a vise grips. Screwed right out super easy.
The heat from a tig is much more intense than that of a mig, stick or gas type torch. You can also pin point the heat with a tig much more accurately than the rest. The high heat, accuracy factor and the ability to add filler only when wanted is so much better.
I've done two more smaller studs in aluminum in the same fashion since with the same results.
My tig torch is not just a welding tool anymore.
opsled