Welding nut onto alloy bolt?!?!

[h3rman]

Ok, I've taken my manifold off my car and all 4 turbo to manifold bolts have snapped flush with the turbo flange.

I have tried welding no less than 10 nuts onto them and every time the weld breaks. It usually seems like it has a good hold at first, but after a couple of turns with the breaker bar the head comes off and the bolt has not moved at all. You can also see after doing the first tack that a lot of carbon is generated ontop of the bolt which surely doesn't help.

After a bit of digging I've come to the conclusion that these are some sort of alloy and not standard steel bolts.

Now I REALLY don't want to sit and drill 4 of these. Have already had the displeasure of doing one and it was a nightmare!!! Took the better part of 4 hours with brand new cobalt drill bits.

Also the 2 at the back have poor access due to being slightly slanted towards the engine. Car is an Evo 5 if that helps anyone, but what I really need to know is what gas and welding wire do I need to make a mild steel nut hold onto these bolts/studs??

I have a Clarke 151TE mig, CO2 gas, Argon/CO2 mix (86/14), mild steel wire (0.6mm) and stainless steel wire (0.8mm) at the moment.

Would the stainless wire and Argon/CO2 mix work? I have not tested it yet. If not can someone please point me in the direction of some proper wire and gas that will get it to hold?

Thanks!

 

[hotrodder]

I take it a couple of turns = a couple of 'bites' rather than complete revolutions? If you're managing to move the breaker bar some distance before the weld lets go it sounds to me like the weld is breaking in a ductile manner. If fancy alloy steels were messing with the welding a brittle failure would be more likely... not moving and then immediately snapping when you lean on it. The bolts could be a quenched and tempered carbon steel or an alloy steel, the issue with this sort of thing (why they snap and why they're a PITA to drill) is usually a mixture of heat cycling + corrosion from the environment the bolts live in

Dunno what flavour stainless wire you have but probably 308 or 316 L / LSi? It might fare better than the mild steel wire or it could go break in a brittle way instead. Going and buying different wire and/or gas is probably gonna end up close to, if not more expensive, taking the manifold to somewhere that can attack it with oxy i would have thought?

Instead of partially filling the nut with a tack try turning the welder up and hitting it in one go.

 

[h3rman]

Yes mate, like you said it's a ductile kind of break, not brittle. Yes I have stainless 308 LSI welding wire. As for taking it somewhere with oxy I had them all glowing cherry red before trying to remove but all 4 snapped flush with the turbo flange, so literally have 2x choices now. Drill or weld, and I would much rather weld!

Not to mention the car is in bits and I would have to remove the turbo to get it done by a machine shop, etc.

I will try using the stainless wire and Argon/CO2 mix and see how I get on. Oh, I have tried both tacking a nut on and hitting it with 1 solid hit and filling the nut with weld. Both fail the same way, the latter might be marginally better though.

 

[Tiggy_dorset]

after welding on a nut, are you letting it cool before attempting to turn it? When hot, the stud will be expanded making it even more difficult to remove. Ideally the stud needs to be cool and the manifold needs to be hot and expanded for a better chance of removal.

 

[wheresmejumper]

Yes mate, like you said it's a ductile kind of break, not brittle. Yes I have stainless 308 LSI welding wire. As for taking it somewhere with oxy I had them all glowing cherry red before trying to remove but all 4 snapped flush with the turbo flange, so literally have 2x choices now. Drill or weld, and I would much rather weld!

Not to mention the car is in bits and I would have to remove the turbo to get it done by a machine shop, etc.

I will try using the stainless wire and Argon/CO2 mix and see how I get on. Oh, I have tried both tacking a nut on and hitting it with 1 solid hit and filling the nut with weld. Both fail the same way, the latter might be marginally better though.

isnt that the opposite of what you need to do?

 

[h3rman]

Yes, I am leaving it to cool down and also heating up the flange with a torch.

 

[h3rman]

isnt that the opposite of what you need to do?

Not the actual bolts glowing, meant to say got the flange around all the bolts glowing.

 

[wheresmejumper]

the freeze spray that plumbers use might've worked,bit late though

 

[h3rman]

Getting quite annoyed with this now...and it's started to rain, so can't keep welding, however the stainless wire with Argon/CO2 keeps breaking in the same fashion.

Plan B is to drill out 1 more bolt (diagonal of the already drilled one), then refit the manifold with new gaskets, 2x bolts (with nuts on the other side) and simply weld the other 2 corners in place. It's a bodge, I know, but really don't care any more. Next time that manifold comes off the turbo will be going with it and both will get binned for newer/better items!

 

[wheresmejumper]

isnt that cast iron you'll be welding?

 

[h3rman]

Manifold, no, its aftermarket (not a hugely expensive one though, so don't care about it)....however I think you're right about the turbo!! Damn it! Plan B is out then.

EDIT: New plan B! Replace the turbo hotside! Simple!!

 

[pedrobedro]

The studs will be stainless, getting them hot makes them break even easier. I ended up buying a manifold for my Kia after the studs broke off flush and a drill wouldn't touch them.

 

[h3rman]

Yup, on the search or a new/used turbo hotside! If I can't get a used OEM one I have found a company that does excellent quality copies for good money. Reviews from Driftworks on them look excellent and those guys really abuse their cars. Have managed to remove the hotside, actuator, elbow & O2 sensor in 1 piece with the turbo still attached to the car.

Will be much easier to just cut the hotside to elbo bolts off and fit the elbow to the new hotside with new bolts. Will cost more money, but a lot less stress involved!

 

[dannyp]

on snaped studs / bolts that drill wornt touch in the past i've foun useing big pillar drill with powerfeed and plenty of suds dose the trick. or if that won't do it or cant use it for whatever reason it often possible to blow bolts out of holes in turbo houseings and manifolds with OA kit as long as the holes arnt blind

 

[outofthefire]

Try welding a nut on then spraying it with plumbers freeze spray the temperature shock should help free the stud plus the cold will cause the stud to shrink a bit. If it moves a fraction soak it in wd40 or another penetrating oil and tighten it back up then loosen it again. Work it in and out giving it liberal squirts of wd40 dont rush and eventually you should get them out.

 

[lincoln17]

Try building the sheared stud up with weld, I normally do this with a stick welder and 2.5mm 7018 rods. The important bit is to tap the welded stud with a hammer every 2 -3mm of build up. You also need to ensure you cover as much area of the stud as you can, which is difficult with small studs. The hammering will break the corrosion on the threads. Once you build it up enough, you can slip a nut over the built up, protrusion and weld it in place. Then more hammering and leave it to cool. Try moving the stud back and forth before you try to undo it, and lash it with plus gas or wd40.
I hope this helps, regards lincoln17.

 

[philpullan]

i find it helps to chamfer the inside of the nut so the weld gets to the stud before welding to the nut and the stud in small parts. seemsyouve taken it of now anyway so if its off why not get a machine shop to get them out for you and simply bolt it back up ?

 

[nickk]

not sure if you've tried it,....but if i was to weld to an unknown steel alloy i would always pre-heat the part first.