Broken stud repair problem !!!!!

[Pitbully]

Hi Guys,
After an extensive search lasting a good few months, I found an untouched A12 aluminium GX Head.
New guides and seals fitted, new valve seats, new valves. Then fitted it. Found a small leak at the rear welsh plug. In the process of taking the head off again to fix the welsh plug, then I broke one of the studs off. Tried with a vice grip and wrench to get the remaining stub out but it then broke off flush with the metal surface. OK no problem drilled a small 6mm hole inside the stub to get it out with an easy out.

I never knew steel could adhere to aluminium so strongly as the other studs came out very easy.I liberally applied penetrating liquid and left it for more than four hours to penetrate.Then heated it with a torch to get it out, and in that process I managed to break off the easy out again inside the original stud flush with the metal surface.... It wont drill out as the metal is probably even harder than the drill bit itself . I have tried tapping it with sharp punches to get it to turn. no luck. I have even tried to cut a 2 mm crosscut in the stub with my die grinder to get it to turn with a screwdriver, 4 stuffed screwdrivers later no luck.

I am outta ideas/plans to fix this....Please help !!!!!!!!:sad2:

 

[Yugguy]

Is a welsh plug like a normal plug only it hates the english?

 

[Pitbully]

Yugguy,

hahahaha!

I actually came across another thread on the net aswell about someones mom really being welsh and also wanted to know what it was.
normally refferred to as a welsh plug, no connotations actually. Also spelt as a "welch" plug.

I used a whole lot of other abbreviations today while getting the welsh/welch plug out, little did i know what was about to happen with that darn stud !!!!

 

[boostnturbos]

the only other thing i no that might get it out is to TIG weld a very short (25mm long) bolt onto the easy out and to the stud. try un-screwing it very slowly. if it brakes off, weld it back on and put it all in the freezer over night. take it back out, heat around the stud and try again straight away. failing that ur gona have to put it in the mill vice an use a magnetic drillblit in the mill. choose a size that drills out the threads exactly, dont bore any deeper than the depth o the stud otherwise it wont come out. fill it in with chemical metal, re bore and re thread. worked for me.

 

[Yugguy]

I had to do something similar on a vectra gearbox casing a few years back, I was skeptical about wether liquid metal would work but it did, quite amazing stuff.