Removing broken & rusted studs: mill or weld?

[rcx132]

There are two decent methods for removing a broken and rusted in manifold bolt. One is to weld a washer and nut to it, the heat of the weld crushes the rust. Apparently very reliable but I dont have experience doing it. Another is to use a centre point drill and left handed bits to drill it out in a mill. I fell more comfortable doing this but apparently less reliable.

What are your experiences, which would you go for?

At the moment I've just glued a reservoir around the studs so it's sitting in a pool of penetrating fluid (acetone + ATF).

 

[Morrisman]

I’ve used the weld method a lot more than drilling, but I’ve not done 100’s, just a couple dozen over the years.
Use a washer with the hole same diameter as the stud, then a nut that is also bigger, so you can get a good hot puddle of weld in there.

 

[barracuda816]

I would also go for the weld method first quicker with no setting up in the mill. If it fails you will have to set it up in the mill and might swell drill it out then.

 

[Nederlands]

the use of a drill is way more difficult
And a lot of hobbyist dril off center or break the drill
After that a diamont (dremel)bit is you're last chance.

Welding is faster and easy.

And yes i did hondreds off them,
And mostley on expensive car's

 

[rcx132]

If youre interested, this is how I'm doing the penetration soak.

 

[Nederlands]

Never did that
When welding the oil burns in bad for you're health stuf.

But if you don't need to weld its great

 

[rcx132]

Never did that
When welding the oil burns in bad for you're health stuf.

But if you don't need to weld its great

I know. I dont weld much, so I just use a low profile charcoal filter that fits under my mask and a slow fan nearby to blow stuff away gently without affecting the shielding gas. Bit worried about the penetration fluid messing with the weld.

 

[Nederlands]

Weld does'nt have to be pretty

Mig will do better than tig when there's oil

 

[Pigeon_Droppings2]

How about a bit of both...use a large drill to slightly dish out the bolt and then go with the weld.

 

[Nederlands]

Just weld

When the first nut breaks off
Just weld another one on

You don't want it to break off
(The bolt)

 

[pint]

yeah the washer trick, works every time*

*99.99% at least

 

[Keithmac]

Steel fasteners corroded into aluminium is a nightmare.

I go all our now to remove the nuts, half an hour cutting and splitting the nuts is time well spent.

Suzuki had a phase of using stainless Allen bolts to secure exhaust manifolds, they seldom came out without issues.

I like watching people milling these out to the point of pulling the thread out like a spring, very satisfying!.

 

[indy4x]

If you a putting it in the mill, try using a slot drill instead of a normal drill bit. Drill bit always seems to want to wander but the slot drill you can plunge straight in.

Have done several snapped of bolts and studs using this method, take the bulk of the stud out with cutter and then pick the threads

 

[dave h 2]

If you do weld, make sure the bolt gets red hot the alloy head will whip the heat away so will not melt.

 

[winchman]

I have heard Mouse Milk is good but never used it.
I heat them up or weld something on to them, I do have a set of left hand drills which have saved me a few times.
I do remember someone making a holding pot like yours but using something that ate away the steel but didn't touch the ally butI may be dreaming?

Mousemilk Oil LAS Aerospace Ltd

www.lasaero.com