Topic: Broken Stud, What method of welding is best for removal?

[odin836]

Well, I've read about it, knew that it could happen and now it has...
I am however still a fan of the "bend at 90 deg method" to crack the bond, worked on 15/16, thats 93%...

After reading about the situation on the forum and possible solutions I've chosen to go with "welding a bolt" to the remaining stud method, it seems to make the most sense to me...

QUESTION - What is the best method for welding a bolt to the stud?  Arc, Tig, Mig etc?  Whats less likely to damage the case?
The answer to the question will allow me to find the best machine shop for the job...



Below shows the success and failure of 30 minutes work.






Cheers!

[bucky katt]

why not just grind the stud off at the deck surface and drill it and use an easy out?

[odin836]

Getting a professional to weld a bolt to the remaining portion of the stud seems the safest bet.
If that fails then I still have the option of grinding it flat & drilling it out, well thats the theory...

[bikebitzofvt]

IMO - Have a nut TIG welded to the remaining stud.  The intense heat will help release the stud from the case.  Once you try it and see how great it works you'll either:

A) Become really good friends with someone with a TIG
B) Go buy your own.

I'm still on "A" - I'm lucky that the owner of my local welding shop enjoys VMX as much as I do!  However, I'd like to make it to "B" one day.

Been there, done that with the easy outs - they're pretty pointless for a stress break.  They work great for mechanical hardware failure i.e. a bolt head snaps off while torquing or brake caliper bolts ground down on the pavement, etc.  That high tensile strength stud wouldn't just snap if it wasn't stuck securely into the engine case.  An easy out basically works like a wedge, forcing the remaining stud even tighter into the surrounding metal.

My only other suggestion would be to file it flat then cut a slot in the top with a hacksaw with a doubled blade.  Apply copious amounts of heat to the case, use a flat bit in your impact driver, and pray.

Good luck, and let us know how it works out!

[jpswino]

That heat idea I think is why welding a nut to the top works for most people. It seems to break things loose a little while putting that nut in place for the wrench. Good luck. Might just take it to a machine shop if all else fails. They can do it quick and easy for cheap.

[754]

A lot of muffler shop ( at least the one I deal with) use the weld method to get out broken studs... with a mig.

 Bet their min charge is a LOT lower than most machine shops.

 A lot of migs around should work fine.

[JohnG]

You still have a fair amount sticking out to hook onto so heat sounds like a good way to go.

If you dont have heat but are good with a drill or have a drill press,  start by drilling a small pilot hole right in the center.  1/16th inch for example.  Then drill progressively bigger holes using that as a guide.  At some point there is little enough left that the pressure on the hole ceases and you can remove it or even collapse it inward.  One advantage is your threads are still intact.

Quality penetrating oils like PB Blaster are good a day before the heat. Forget WD40.

[nokrome]

that very same stud broke when i was tearing down the engine on my project bike, must be something about the location
   +1 on the penetrating oil, let it soak for at least a couple days (be patient, it will pay off)
      looks like there might be enough stud sticking up to grab it with a good pair of vise grips, dont forget the heat

[JohnG]

same one that broke on me.... 

[odin836]

nokrome & JohnG,

What method did you both use to get yours out?

Cheers.

[nokrome]

i ended up taking mine to a machinist friend after i tried to get it out with an easy-out, he got the stud out but i had already jacked up the threads from my previous attempts, so ended up having to have an insert installed

[JohnG]

This was 30 years ago....  I used heat and an Easy Out.  I am not much of an Easy Out fan today.... but it did work.

[mec]

thats how it looks like when you TIG weld a nut to the stud and turn it out.

mec

[odin836]

I'm taking it to a local welding shop first thing tomorrow morning before I go to the office.

Hopefully its straight forward, seems simple enough...

I'll post results later tomorrow.

[Seamus]

Probably too late now, but I had a flat piece of bar, driller a hole to allow the stud to fit through and welded it to the top of the stud (with an arc welder) and it came out very easily.

Good luck

Seamus

[odin836]

Well, 1st attempt has failed.
Tig welded a 14mm nut to the top of the stud, long after it was welded the case was heated, and unfortunately it poped right off after applying pressure.



I'm uncertain that adding a T bar etc to the top of the stud will make a difference, as the force of the twist is still isolated to the top of the stud.

Someone at work mentioned they know someone who performs "Spark Erosion", so I may give that a try as it seems safe enough.

Anyone tried this and had success?

[cycleman]

Mig works fine.  If the first attempt failed just weld another on & I would weld it more secure.  Doesn't look like much of a bead was placed inside the nut.

If you have an air hammer, once the nut is welded on, give the nut & broken stud a shot with the air hammer.  The vibration loosens things up.

Impact's work really well at removing exhaust & head bolts because of the vibration.  You are much less likely to break the stud if you use an impact to remove.  With all the aluminium around I wouldn't use an impact to install any nuts, bolts etc.

[NickC]

Place the nut on there, and fill her up with the MIG. Don't be shy with it, you aren't going to hurt the block...

[754]

By Spark Erosion do you mean EDM ?

 Excellent method, cuts thru broken taps even!  They can, if set up right burn a hex hole into it so you can use an allen wrench

 Sometimes they are reasonable cost.

[MJL]

My method is welding a nut on. I use one size larger nut than would fit on the bolt or stud. I have had greater success that way. 99% of the time I have used a mig. It will get nice and red hot, wait until the redness goes away before you try to turn it. If you turn it too soon, the metal is hot and soft and will twist off. Waiting also gives the case some time to absorb heat and expand, helping to free the bolt.  I thought about this method with a stick welder and decided to change it a bit as I didn't want the slag in the weld. Instead I welded a washer to the stripped out screw in this case and then welded a nut to that.

[odin836]

Yes, EDM is what was meant.
I'll see if I can find someone who will attempt Mig whilst I wait, that way I can be sure of the bead being made etc.

If that fails EDM it is, I've got much better things to do with my time that re-visiting machine shops.
Like actually putting the engine back together! 

I'll let you know how I go and post results, especially if I use EDM.