Glenn
Well-Known Member
Different metals expanding at different rates I guess.
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- Thread starter Jokenring
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crash2
-Oh no I picked a side-
But the heat transfer is instantaneous so I would think expansion would happen both with the bolt and the surface around it. Now granted yes I could see the different metals expanding at different temps--but the bolt would expand faster.
Thats how I would see it by basic physics
Bodaciouscj7
Well-Known Member
True but it always seems to work at the shop. I always spray it with pb blaster after the weld so maybe its the heat quench that helps in that case.
psychodelicdan
Well-Known Member
This is a bit wordy but bear with me.:76:
The stud will heat much faster due to the insulating properties of the corosion.When the stud expands it in essense compresses the corosion. Then when the stud cools
and shrinks much like in flame straighting. it can help to release the grip on the threads You can help it to cool with a gental squirt of water to help "shock" it.
From my years doing field service of heavy equipment I learned a great trick a removing bigger studs.They can be broke off rather deep in the hole, even on aluminum castings. This method works well if you have the nerve to try it.
Step 1. Get a stick welder.A rod like 7018, not a 6010 like rod is best.
This can also be done with duel shield if your good. The big trick to this is the flux will fill in and protect the threads while you build a nice new stud on it to weld to the nut as mentioned earlier.
Step 2. When using the stick, you disconect the ground, insert the rod down in the bore centered on the stud.
Step 3. Very carefully hook up the ground to start the arc. This is best done by a helper so you can keep the rod centered.(You at ALL COSTS do not want to strike an arc on the threads!!):loosero this and its time to head to the drill press and good luck drilling through what you just did.:fawkdancesmiley: and feed the rod STRAIGHT down on the broken stud.let the flux flow out into the threads .I will build weld up on the stud and the flux will flow in to the threads to protect them for the stud to screw out on.:cheer: This like all welding takes some practice.
best of luck I hope this passes on something usefull.:nana1:
The stud will heat much faster due to the insulating properties of the corosion.When the stud expands it in essense compresses the corosion. Then when the stud cools
and shrinks much like in flame straighting. it can help to release the grip on the threads You can help it to cool with a gental squirt of water to help "shock" it.From my years doing field service of heavy equipment I learned a great trick a removing bigger studs.They can be broke off rather deep in the hole, even on aluminum castings. This method works well if you have the nerve to try it.
Step 1. Get a stick welder.A rod like 7018, not a 6010 like rod is best.
This can also be done with duel shield if your good. The big trick to this is the flux will fill in and protect the threads while you build a nice new stud on it to weld to the nut as mentioned earlier.
Step 2. When using the stick, you disconect the ground, insert the rod down in the bore centered on the stud.
Step 3. Very carefully hook up the ground to start the arc. This is best done by a helper so you can keep the rod centered.(You at ALL COSTS do not want to strike an arc on the threads!!)
:loosero this and its time to head to the drill press and good luck drilling through what you just did.:fawkdancesmiley: and feed the rod STRAIGHT down on the broken stud.let the flux flow out into the threads .I will build weld up on the stud and the flux will flow in to the threads to protect them for the stud to screw out on.:cheer: This like all welding takes some practice.best of luck I hope this passes on something usefull.:nana1:
psychodelicdan
Well-Known Member
If you do it right you can use this methodto pull out a broken easy out first to let the presure off the threads
ain'tstuckjustresting
RIP Mister 12/5/12
Being heavy equip. tech myself I agree with you, the trick is definitely to let the bolt/stud cool before you try to back it out. It also helps since the weld is very soft when warm and will tend to twist off (captain obvious).
I have found on very large bolts that are broken off deep in a bore, stuff a piece of pipe in the hole 'till it touches the bolt/stud. Crank your 7018 up and jam it down the middle of the pipe. You weld the pipe to the bolt with very little worry of damaging the threads. You can then just use a pipe wrench to spin the bolt out. :cheer:
I have found on very large bolts that are broken off deep in a bore, stuff a piece of pipe in the hole 'till it touches the bolt/stud. Crank your 7018 up and jam it down the middle of the pipe. You weld the pipe to the bolt with very little worry of damaging the threads. You can then just use a pipe wrench to spin the bolt out. :cheer:
Binder
Well-Known Member
When I was a youngin, like 13 my uncle had a business doing field work on heavy equipment and I would help him on some jobs. When replacing the rollers on a Cat the bolts would often break, these are larger bolts. What he would do is dig a hole in the center with a cutting torch then while hot drive a large easy out in the center. Take a very wet rag and try to quench it which is a bit tough to do being it's upside down but this would get those large bolts out...
zukkev
Cornfuzzled yet again...
That was a long time ago huh!!!:fawkdancesmiley:
Binder
Well-Known Member
:flipoff:.....I turned 13 in '78..
The '80's were in between now and then too. It's amazing I remember any of it!:haha:
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psychodelicdan
Well-Known Member
That pipe trick is the stuff.I've never thought of that one.I wonder how many hours that would have saved.
Yep digging out track roller bolts late at night laying in the mud in the freezing rain sure are fond memories:cheer: Yea you got the track backed off, wood blocks or what ever you have or can find holding the machine up off of them. Your head shoved in there 4" from the hole over your face burning slag dripping on you the torch popping and snapping all the while in the back of your mind hopeing the blocking dosent fail.:shaking:
Hijack over.:haha:
.I wonder how many hours that would have saved. Yep digging out track roller bolts late at night laying in the mud in the freezing rain sure are fond memories:cheer: Yea you got the track backed off, wood blocks or what ever you have or can find holding the machine up off of them. Your head shoved in there 4" from the hole over your face burning slag dripping on you the torch popping and snapping all the while in the back of your mind hopeing the blocking dosent fail.:shaking:
Hijack over.:haha:
CHOP SHOP
Well-Known Member
ain'tstuckjustresting
RIP Mister 12/5/12
We had a run for a while where the Deere/Hitachi shovels were breaking rotex bolts left and right. They were 24MM bolts and usually broke off 2-3" up inside the bearing. They almost never had a flat face so drilling was a real bitch. The pipe trick was the only way we could get them out w/o undecking the machine.
Broken Again
Well-Known Member
FWIW...I have used nitric acid to remove steel studs in alum heads...
Just don't use too much and flush like crazy when done.
Another method I use for removing broken taps etc, is to grind a carbide bit to a chisle point then plunge the hole at about 2000 rpm with .3 IPM feed...lots of coolant..
Gonna need to pull the head for that thou.
Just don't use too much and flush like crazy when done.
Another method I use for removing broken taps etc, is to grind a carbide bit to a chisle point then plunge the hole at about 2000 rpm with .3 IPM feed...lots of coolant..
Gonna need to pull the head for that thou.
