TIG use case - remove broken bolt in manifold

[Olli]

@pod70 - yes they are. I thought about putting a bit copper paste in exposed thread of the manifold to prevent this melting in conjunction with the short bursts mentioned above.

 

[Olli]

Here are the pictures as it is now (nothing removed) ... May be one bolt (first picture) is only missing.

 

[gordon stephenson]

Another method that I have used with very good results, is to drill down the centre of the stud then grind an old allen key etc to a square with nice sharp corners and squared off bottom, Then drive it into the stud, cutting the drilled hole to suit your ground square, with no added expansion it should now wind out, (in all my years in industry i have never known easy-outs to work on a seized broken bolt/stud)

 

[mtt.tr]

Another method that I have used with very good results, is to drill down the centre of the stud then grind an old allen key etc to a square with nice sharp corners and squared off bottom, Then drive it into the stud, cutting the drilled hole to suit your ground square, with no added expansion it should now wind out, (in all my years in industry i have never known easy-outs to work on a seized broken bolt/stud)

Torx bits are really good for that.

 

[Olli]

I thought about how to gather experience for the TIG welding approach. Here is my test scenario:
I bought a threaded rod M8 (imperial sizes are hard to get - at least in a hardware shop here in Germany) along with suitable nuts. I cut the rod in small peaces, welded it on a plate an bolted nuts on them, so that there is a recession left. Then I began to weld a tower on the rod so that I was finally able to weld a second nut to the tower. If the lower nut is freely movable and the upper can’t be torn off then this should be similar to the situation of the bolt in the cylinder head.
I chose a 2.4 Tungsten and around 100A short bursts and it worked (upper right) ... I can’t simulate the rust, of course. However, what do you think?

 

[Turbo]

I thought about how to gather experience for the TIG welding approach. Here is my test scenario:
I bought a threaded rod M8 (imperial sizes are hard to get - at least in a hardware shop here in Germany) along with suitable nuts. I cut the rod in small peaces, welded it on a plate an bolted nuts on them, so that there is a recession left. Then I began to weld a tower on the rod so that I was finally able to weld a second nut to the tower. If the lower nut is freely movable and the upper can’t be torn off then this should be similar to the situation of the bolt in the cylinder head.
I chose a 2.4 Tungsten and around 100A short bursts and it worked (upper right) ... I can’t simulate the rust, of course. However, what do you think?

Good idea to practice. A tip I can give is to put a washer at the top of the hole before you start, saves you accidentally arcing onto the cylinder head!

 

[Pete.]

Pull one of the other studs and measure the depth of the drilling in the head. Get a tapping size drill and grind all the edges of the flutes rounded so it doesn't cut on the sides, except for the very last bit under the lips. Used that to spot the top of the broken stud. Get a slightly smaller drill, left hand if you can. Mark the drill shank at the depth of the hole so you don't run into a gallery then use that drill to drill out through the bottom of the broken stud. Go up in sizes up to the tapping size until the remainder is loose enough to pick out.

 

[Dcal]

Looks good @Olli can you post the photos full size so we can zoom in, but I think you've got the hang of it.

See the post in the link below, where I've done something similar in a steel flange (easier to weld to the flange by mistake, but it worked fine)

If it doesn't work do as @Pete. suggests in his post but the tig trick is well worth trying first. The intense localised heat really helps free it up.
I have a few photos of doing it with a washer first somewhere but can't find them.

https://www.mig-welding.co.uk/forum...the-brink-hopefully.81348/page-9#post-1336251

 

[cianh91]

I drill them and hammer in spline bits have done loads and had very little fails with this method .
Using a left hand drill if you can get one (works with normal right hand aswel but sometimes the left hand bit will catch it enough to do the job) smaller than the spline bit drill as close to centre as possible then gently hammer bit in . Torx bits work but I found they don’t like being hammered in as much

 

[Olli]

My challenge is nil experience with any method. So something that I can practice on is my preference to either gather confidence or realise that a pro is the better choice :-) . @Dcal - I have got no better resolution at the moment.

Olli

 

[Dcal]

I have got no better resolution at the moment.

When you upload a file it gives you the option of Thumbnail or Full Image.
Chose the "Full Image" option.

Is the head on the bench?
When you have got the hang of welding washers to a stud give it a go, but make sure you can get at it comfortably before you try to weld it.

 

[Olli]

@Dcal - all preparation at the moment. October will probably the start of the actual tasks on the engine.

Olli

 

[RichardM]

On the subject of drilling, you could make a pilot guide out of a cap head screw with a hole drilled through it (preferably on a lathe) screwed in to the hole to allow the first hole to be drilled correctly. Then carried on as above by @Pete.

 

[Olli]

@RichardM - thanks.

 

[Olli]

I ordered this, too, regarding drilling:
https://www.amazon.com/BIG-GATOR-TO...6763&s=gateway&sprefix=big+gat,aps,208&sr=8-9
This is the metric not imperial version because the core bore of 3/8" is 8mm ... and left-drill metric bits are easier and faster to come by here in Germany.

 

[Dcal]

I was changing bearings in an electric motor tonight and broke a screw in an end plate, so took a few photos of the process of removing it using the tig method.

Not the same as yours (3mm screw broken in aluminum) but the procedure is the same.
For this I used a really sharp 2.5mm tungsten and about 35 amps (No idea if this is anywhere near right but it worked for me)

There is a slight step in the end plate which stopped me welding a washer over it so I just built up the top of thread with blobs of weld.

Then put a 5mm nut over it and welded it to the blob.

Put plenty of heat into it to heat the seized thread
I let it cool a bit and it just screwed out.
I didn't even need to run a tap down it to clean the threads.

Job done in about 15min

 

[northwest]

in all my years in industry i have never known easy-outs to work on a seized broken bolt/stud

They are guaranteed to fail. Think about it, you drill a hole then drive a wedge in (Tapered left handed, hardened pin that spreads the hole wider the more force you apply). How is this going to work?
My vote for a) the most inappropriately named tool and b) the most ineffective tool - ever.

 

[Pete.]

Easi-outs are for removing broken bolts/studs, not seized ones.

 

[angellonewolf]

^^^ but the only reason for the snaping is there seized ?

 

[Dcal]

Not so, they can snap because of overloading or fatigue any other number of reasons.

I agree that easyouts are useless and I've never had any success with them.
I just throw them in the scrap now or keep them for when I need a bit of high carbon steel.