Broken bolt extraction - how would you handle this?

[pen15]

I have removed many broken exhaust studs in aluminum heads by Placing a flat washer slightly smaller than the broken bolt over it and welding thru the center onto the stud. Much easier than the nut method because you don't have to reach all the way thru the nut. When the washer is welded securely pick any random nut to weld thru the center to the washer. Wait 30 seconds for weld to harden and back it out. Never failed.

[sc_rufctr]

Originally Posted by Charles Freeborn

Carbide tipped masonry bits are intended for hammer drills - not what you want here.
Google "Diamond Grinding Burrs", and be prepared to heli-coil the holes when you're done.

Did you watch the video?

[billybek]

Originally Posted by sc_rufctr

Did you watch the video?

I was surprised they worked as well as they did....
Cool, more tricks to pull out of the bag when all seem to be lost!

[1990C4S]

Desperation trick that can work:

Drill a 1/4 or 5/16 hole down the center.

Drive a piece of 1/4" or 5/16" cold rolled shaft into the hole you drilled, leaving 3-4" protruding.

Connect a stick welder ground to the case, the other lead to the cold rolled material.

Toggle the welder on and off. This will the bolt safely, no flames required.

Pull the cold rolled material out with vice-grips (it might even extract the bolt). Then use an easy out.

[Geary]

Would suggest you die grind away the small portions of the flange required to do the welded nut extraction.

[widebody911]

I opened up the hole a bit using a carbide rotary burr, which cut through it like butter - once i had a hole up the middle opened. If you look closely you can just make out the original threads.

[Joe Bob]

EMS, some of them do onsite removal....

[scottmandue]

Originally Posted by Joe Bob

EMS, some of them do onsite removal....

I was about to ask about this, a long while back my brother broke off a stud in the head of his Mercruiser (saltwater).

He took it to a shop that drove it out electronically, is that what you are talking about JB?

Thou it looks like WB is doing pretty good so far.

[sammyg2]

EMS, EDM, elox, lots o'names out there for this process.
I used a company called The Hole Shop for 30 years, they'd show up and get any bolt out no matter what, and never left a mark.
The owner retired a couple years ago, Lots of em on google.

Pretty pricey tho. over $100 an hour with 4 hour minimum for most shops.

Cheaper if you can take it to them. faster too.

[javadog]

Originally Posted by scottmandue

Thou it looks like WB is doing pretty good so far.

Well...

He's gone a little too far with the grinding. He's at risk of damaging the threads in the case.

What he needs to do is to apply some heat to kill the loc-tite and to unscrew what remains of the stud threads from the hole. It would be nice if he hadn't ground through the thread roots of the stud already, but maybe he's got enough left of the stud at the bottom to drill a (smaller) hole all the way through it and use an easy-out type of tool.

[scottmandue]

Originally Posted by sammyg2

EMS, EDM, elox, lots o'names out there for this process.

Is that the electronic process we were talking about?

My brother worked on that head for weeks then someone turned him on the a shop that did that.

[sc_rufctr]

Here it is...

Porsche 911 EDM Broken Bolt and Stud Removal | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article

[john70t]

Originally Posted by javadog

He's gone a little too far with the grinding. He's at risk of damaging the threads in the case.

What he needs to do is to apply some heat to kill the loc-tite and to unscrew what remains of the stud threads from the hole. It would be nice if he hadn't ground through the thread roots of the stud already, but maybe he's got enough left of the stud at the bottom to drill a (smaller) hole all the way through it and use an easy-out type of tool.

Totally agree.

I once had one of those beautiful round grinding bits (S&K was my brand I think) and they worked on everything flawlessly.
They never failed to remove any steel material but they do bounce around quite a bit.
Not precise at all.

This might be a swing in the dark..but:
1). What about marking the thickest portion of the remaining material to determine angle change and your progress.
2). Getting a 1/4 rounded piece of sheet metal and placing it over the exposed threads to protect them, maybe some grease under.
3). Use a left handed easy-out with heat, making sure all the junk metal inside the hardened sleeve or timesert in the case (consisting of all former stud material +sheet metal) turns as one unit within the thread bore.
4). Or cut a line into the thickest part and drive in a screwdriver to turn everything.
5). Followed by a tap to clean up threads and go from there. May need a helicoil after if threads are damaged.

[widebody911]

I spent a little more time on it tonight, mostly straightening up the hole using the carbide burr, and then ran the tap through it. I got in 18mm, (which is better than I did on Prom Night) but the threaded portion of the original studs is 25mm. Now I must decide if I rest on my laurels and stop here, or try to get another 7-8mm and risk buggering up what threads I have left.

[Jandrews]

Originally Posted by widebody911

...(which is better than I did on Prom Night)

LOL!!! Classic!


JA

[javadog]

I think you need to remove the whole thing. That's what I would do.

Sometimes when people face a problem they've never dealt with, their solutions are limited to what they have on hand or what they've done before. I feel this is a short sighted approach, particularly when you're dealing with something that is expensive or rare and the chance of ruining it is too high.

If I had this problem of removing the remaining piece, the first thing I would do is take a bolt of that size down to my favorite machinist and have him make me a drill bushing out of it. It would take him about two minutes, cost me maybe five dollars, and then I would have something I could use to drill accurately through the center of that hole. I would then hit the stud with some heat, and remove it using an easy out.

Ironically, when I first saw this thread the other day, I was dealing with a similar situation. I wasn't working on an engine case but I was working on a used part that had a bolt snapped off in a hole, and within two hours, I had the thing out and was on to bigger and better things. Trust me, you can get this thing out.

[Neilk]

Can you get a steel sleeve/bushing the size of the bolt and use that as guide for your drill bit, something like the picture below?

[javadog]

Possibly, he could go down to his local hardware store and rummage through all of the bushings they have and see if he happens to find one that's about the right size. Or he could spend the same amount of time and get one made, like I suggested.

The horse has been told where the pond is, now it's up to him to mosey on down there.

[VincentVega]

good idea with the bushing

Get it out and be done with it. Center punch, small drill, bigger, bigger... use the bushing. I've used a piece of whatever I've had around in similar fashion. Once you get close heat it up, use penetrating oil, wax, heat it up... sometimes you can peel the remaining bits away from the threads.

Take it easy with the die grinder

[widebody911]

I like that bushing idea; if I get a chance tonight I'll try it.

Unfortunately my first priority when I get home from work today is to address my SMG failure