Welding a nut onto a recessed broken stud.

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At 13:00, the stud is recessed down in a hole.How does the nut get welded to the recessed stud?You just put the nut above the stud, and the melted wire will just pool inside the nut and melt onto the top of the stud?How long do you do it for?   Do you fill up the entire nut cavity with the melted weld wire?  Last edited by punxbond; 12-19-2015 at 06:01 PM.
Reply:I've never used MIG to do that. With TIG it's relatively easy to deposit a drop of metal onto the top of the broken bit, then let it cool and stack another on top until there's enough protruding to set a nut onto, at which time you can go back and melt the drop into the threads of the nut and add more filler up to the point it's flat. I suppose with MIG you can just align the nut over the broken stud and pull the trigger.-Chris
Reply:In the video, I think he just positioned the nut above the stud, and filled the hole.  Oh yea.
Reply:I'm  a talentless hack and I've  done this with my tool-truck (off brand) mig. Desperation can be very inspirationalEventual master of the obvious, practitioner of "stream of consciousness fabrication".  P.S. I edit almost every post because because I'm posting from my phone and my fingers sometimes move faster than my brain.
Reply:if you have a little carbon paste to coat the threads with it goes good as well, but you  put the nut over the stud and then aim the wire right at the stud through the nut, crank up the heat if its bigger than 5/16 or 8mm and pull the trigger until there is enough melt to fill the nut with the weld starting on the stud. Now wait a few minutes for the intense welding heat to loosen the stud and you might get lucky and be able to just wrench it out. I have about a 60% success rate on the first pass.  I had one piece where someone torched off 10   3/4 inch bolts darned near flush, so got some 3/4 nuts and started welding,  If it sheared off cause its frozen, you might not have any luckLast edited by fast*st; 12-19-2015 at 06:47 PM.
Reply:I have used mig several times with good success...if its deep down in a hole, you can cut copper tubing and put it in the hole, flush with the top and put it in first to protect the threads in the hole, then fillerup right to the top of the nut, let cool and try wrenching it off, if its still really stuck, a few heat cool cycles usually loosens up the most frozen stud or bolt..Of all the things I lost I miss my mind the most...I know just enough about everything to be dangerous......You cant cure stupid..only kill it...
Reply:I didn't watch the video, but I do it a lot to remove recessed bolts, taps, ex-outs, etc.  Lets say you're removing a 3/8" recessed bolt.  I just simply put a 5/8 or larger nut (Black preferred) centered on the hole. I blindly center a mig nozzle on the nut and pull the trigger, trying to center the wire. I keep going until the weld fills the nut.  The heat basically concentrates on the center, then builds up and out in a cone shape. They almost never hurts the base metal, aluminum or iron. After it cools a little, I take it out.  Sometimes it breaks.  If it does, do it again.  Each time it shrinks the stud a little, eventually it comes out. I have a worse case senario on a bulldozer track if you search my posts.  That time I actually used a stick process called Xtractalloy for a bolt broke 2" deep in a hole, which is a rod designed for tough stud removal.
Reply:Its not that far in. Get a 5/16 nut and grind one side to a point so it looks like a lug nut. That will get the nut in closer to the stud shank. Zap a few slugs of the mig to build a slight nugget in bottom of the stud. Then run a bead and puddle up. Let it cool and go for it. When they are that small it can take a few tries and some practice.Ive had to do plenty of diff cover and other small bolts.esab 260 multimasternew tech 150 invertorlincoln 140 cheapo
Reply:I just googled the Xtractalloy rods. I'm ordering a small supply for future use.Eventual master of the obvious, practitioner of "stream of consciousness fabrication".  P.S. I edit almost every post because because I'm posting from my phone and my fingers sometimes move faster than my brain.
Reply:Xtractalloy and other "stud removal" rods are 312 stainless steel. The idea is that the slag will coat the threads and prevent the weld metal from sticking to them. It still requires care and experience to do it properly- if you strike the arc against the threads, you're screwed.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Originally Posted by Silicon-basedXtractalloy and other "stud removal" rods are 312 stainless steel. The idea is that the slag will coat the threads and prevent the weld metal from sticking to them. It still requires care and experience to do it properly- if you strike the arc against the threads, you're screwed.John
Reply:I have a buddy who runs a garage tell me one day that he had just finished a Walker Exhaust clinic on exhaust repair and the topic of the broken manifolds studs on the 6.0 Chev came up. The Walker rep told him it's an easy fix, take your stick welder, hook your ground up the block, turn it up to about 100 amps, hold your rod to the broken stud ,then turn the welder on and off a few times and that old stud will turn right out!............He as much told me I had been doing it wrong for years.........so I asked him to let me know that works for him, haven't heard him mention since! haha
Reply:there are 100 ways of doing it right..what ever works for the person doing it...Of all the things I lost I miss my mind the most...I know just enough about everything to be dangerous......You cant cure stupid..only kill it...
Reply:You guys will probably tear me apart like a pack of Hyenas, But I use my little 90 amp Hobart Handler and .023 wire to take broken exhaust manifold studs out of Cat 3406 engines on a regular basis. Zap, Zap til you have a "bump" to weld a nut onto. It may take 3-4 tries to get one out, but it usually works. The really stubborn ones get drilled  with a 3/16" bit then the hole gets welded from the bottom out, that shrinks the stud to where it screws out with your fingers.
Reply:Originally Posted by 12V71You guys will probably tear me apart like a pack of Hyenas, But I use my little 90 amp Hobart Handler and .023 wire to take broken exhaust manifold studs out of Cat 3406 engines on a regular basis. Zap, Zap til you have a "bump" to weld a nut onto. It may take 3-4 tries to get one out, but it usually works. The really stubborn ones get drilled  with a 3/16" bit then the hole gets welded from the bottom out, that shrinks the stud to where it screws out with your fingers.
Reply:Originally Posted by blackbartI'm not one of the anti 120V machine crowd.  Depending on the size of stud, the Hobart Handler would probably be my first choice of machines for this job. I do try to run it hot and non stop though.