Experienced Welders...

[SRG]

So yesterday, i spent the evening into the late night, removing broken exhaust manifold bolts from my 2006 GMC Sierra with the 6.0 gasser.
I used my Hobart Handler 140 MIG with flux core wire and welded nuts to the remaining broken bolts that were still in the heads. Some were easy as the bolt was protruding like a stud, and some were recessed so i had to make a jig to hold the nuts in position so i could weld, and build them out into the nut. Took some work but got it all back together and only broke one spark plug wire.
Anyway, I got to pondering why when i would weld the steel nuts to the steel bolts, and get them glowing red/orange/yellow hot, does it not effect the aluminum head in anyway? Obviously i never got the nuts or studs hot enough to melt but surely the temp was hovering close to the melting point of aluminum.
Just something i was wondering.


Still gotta do the passenger side. Two broken manifold bolts over there.

 

[Tooljunkie]

Re: Experienced Weldors...

It takes an awful lot of heat to melt aluminum in that manner.
The aluminum draws it away so quickly and the coolant dissipates it.
Break off a bolt below the surface that way and after welding on it, its virtulally impossible to drill.
I havent welded to a manifold stud in years. I probably have removed 20 manifolds in the last year. One month alone was 7. I was fit to be tied.
Lately i rattle the remaining stud with an air hammer,to knock it loose.
No heat, no lube.
Air hammer bit with a concave in the end to keep bit from slipping off stud.
In cast iron heads i use water as im rattling. Rust pours out and stud starts turning.
Hundreds of bolt extractions in my years mechanicking.

 

[skeets]

Re: Experienced Weldors...

Tooljunkie,,, If you can I would love to see how you do that really!!!!! A little video would be way cool and helpful to folks like me

 

[SRG]

Re: Experienced Weldors...

Yeah i'd like to see that too. Seems like it would be a huge pain in the butt with the motor still in the vehicle and a recessed broken bolt. I had a helluva time getting to the very back drivers side bolt with just the little MIG torch. Of course the exhaust was still in position, which really cramped my style.

It worked good tho once i got a good solid weld in place. All of them turned out without issue.

 

[D2Cat]

Re: Experienced Weldors...

Are you using high temp anti-seize when re-installing?

 

[twomany]

Re: Experienced Weldors...

It was the intense heating of the studs that facilitated their removal.

You could have saved yourself the effort of welding on nuts if you had used the "smoke wrench" at the start.

Alu. melts in a funny way. The oxide at the surface hides the fact that the material underneath is molten. But.. Alu conducts heat so readily that it is difficult to get it to molten temps without special care.

 

[SRG]

Re: Experienced Weldors...

Are you using high temp anti-seize when re-installing?

That's the only kind I buy. To me it's like Franks red hot. I put that shiz on everything, that doesn't require a specific TQ number.

 

[SRG]

Re: Experienced Weldors...

It was the intense heating of the studs that facilitated their removal.

You could have saved yourself the effort of welding on nuts if you had used the "smoke wrench" at the start.

Alu. melts in a funny way. The oxide at the surface hides the fact that the material underneath is molten. But.. Alu conducts heat so readily that it is difficult to get it to molten temps without special care.

They were already broken when I bought the truck. Only 3 of 6 bolts on the drivers side. holding the manifold to the head. Worst exhaust leak ever. Plus I don't have a smoke wrench.
I put my hot gloves on and tore into it right when I got back from a 2hr drive. Everything was nice and hot.

 

[TopesRule]

Re: Experienced Weldors...

I have an 05 Sierra with only a couple studs left on both manifolds. It's not leaking too bad yet, but I'm not looking forward to replacing them. I did the brakes a couple weeks ago and when I was hammering off the rotor with am 8 pound maul two of the nuts with the stud threads from the manifold were on the ground when I was done. I'm planning on trying to weld nuts to whats left of the studs and hoping the heat from the weld will help when I back them out.

 

[Yooper]

Re: Experienced Weldors...

All good info so far. You will never generate enough heat welding a small nut onto the broken stud to affect the aluminum head. Take advantage of the heat to try and get the stud out before it cools. Usually, this is enough to break the grip of the ***8216;white powder of death.***8217;

 

[SRG]

Re: Experienced Weldors...

I have an 05 Sierra with only a couple studs left on both manifolds. It's not leaking too bad yet, but I'm not looking forward to replacing them. I did the brakes a couple weeks ago and when I was hammering off the rotor with am 8 pound maul two of the nuts with the stud threads from the manifold were on the ground when I was done. I'm planning on trying to weld nuts to whats left of the studs and hoping the heat from the weld will help when I back them out.

That things gotta sound like a sewing machine. Mine sounded horrible
I put a new manifold on the drivers side. Gonna put a new one on the passenger side too. I had to cut the 3 studs and nuts off at the collector flange (predicted that), so i ordered ahead of time.
Summit has new Dorman manifolds that come with manifold and collector gaskets, as well as new screw in collector studs and nuts.

Funny, i just did all 4 brakes on mine last weekend. New rotors and pads all around and new calipers in back. I had to kick the crap out of the wheels to get them off, and then had to beat the rotors with a mini sledge too. The rotors had to be over 100,000 miles old. They were falling apart, had to have just been a "pad slap" brake job the last couple times.

 

[Tooljunkie]

Re: Experienced Weldors...

Tooljunkie,,, If you can I would love to see how you do that really!!!!! A little video would be way cool and helpful to folks like me

As a matter of fact, i uploaded a video on youtube.
https://youtu.be/_-yZYLaH4xA
I didnt mention i drilled into the end of the air hammer
Bit to make a concave. Keeps it on the stud.
I tried it on a ford 5.4,no water and a gentle rattle,slowly increasing power until i saw white powder coming out. Snug,but a vise grip got them out.
Theres also video showing how i get rotors off too.

 

[Lil Foot]

I'm impressed! That technique will be filed for future use. Thanks for posting.

 

[Fordtech86]

I grew up in Illinois and start my wrenching career there,done hundreds of manifold bolt extractions,tig welder is the most effective tool that I’ve found,can get much better penetration then a mig,especially when they recessed a good bit,but fortunately I left the north about 5 years ago,working on cars is so much easier in central Louisiana with no rust lol

 

[SRG]

Interesting technique, worked pretty damn good! What do you do when they are recessed in the head? And i'm not seeing your brake rotor video.

Why was the title of my thread edited?? Weldor is the person, Welder is the machine. Somebody changed the O to an E.

 

[Lil Foot]

Don't know about the title, but thanks for posting this:

Weldor is the person, Welder is the machine.

I never knew that. Learned something new today.

 

[bearbait]

After buying a Dodge Ram with the 5.7 hemi I found out that they are notorious for breaking off the rear studs in the manifold. This may come in handy down the road, thanks for sharing.

 

[skeets]

TJ,, I dont know where you came up with that but DAYUM I like it!!!

 

[Tooljunkie]

TJ,, I dont know where you came up with that but DAYUM I like it!!!

That method has an odd history. 1 ton cube van. Back wheels were stuck.
A day of fighting and sledge hammering to try and free then from the hub.
Bottle jack between frame and pushed as hard as i dare.
At some point i was washing my hands and water got really hot. Truck was right there and i turned the hose onto the wheel. Jack still behind wheel.
Within 20 seconds the wheels came loose.

Next time was a stuck hitch bar in a reciever. This time was air hammer and water. The crud just poured out.

I have been trying this method on anything that is rusty stuck and nearly every time i have been successful.

40 years around cars, Have to experiment to find better ways.

 

[lugbolt]

Aluminum is an excellent conductor of heat. Similar to copper. You can melt steel in a threaded aluimum part but it won't melt the Al unless you get real stupid with it. Al dissipates the heat MUCH faster than steel does.

Actually this is a good thread. I bought a TIG machine earlier this year and have been messing with it. It's fun. But I have also realized that I'm not very good with it and my eyesight is not great-not good at all actually. What I learned was that with my little 200A machine, I can't weld Al parts that are very thick even with the pedal to the metal at 205A, 1/4" is a stretch. The metal dissipates the heat from welding so quickly that it takes an aweful lot of amperage to properly weld it, a lot more than steel would at the same thickness. It's odd to me. With steel, you're generally adding filler sort of slowly, with Al, you go hot & fast. At least that's what I've found with it. Maybe I'm wrong and I wish there was someone would coach me with it, but again with my eyes not being very good, it may not do much good.

Neighbor guy had an 04 Dodge with a Hemi, water pump was leaking so he was in the process of replacing it and broke a couple bolts off in the block. Got one out with a propane torch and a candle, but the other no good...that dude was in there. Of course by time he calls me, it's broken off flush. I loaded up the TIG, headed over there pulling the welder and cart with all my stuff behind my MF 1145, get there, grabbed a nut that fit sorta over the remainder of the stud, tigged it on, and literally backed it out with a short wrench while it was still hot. Guy was amazed and give me $50 and wouldn't take it back. We're neighbors and I wasn't going to charge him anything but he would't let me leave without a $50 bill.

Tig is a process that I have learned in high school a LONG time ago but the machines have certainly changed. Back then there weren't a lot of controls, now the one I have has pulse, a/c balance, and frequency, which were never an option when I did this stuff in HS, so I don't even have a clue where to start with balance when doing aluminum. It's at about 30% right now and that seems to be where it an I get along ok. Have not used pulse yet, watched Jody's videos and it looks kinda cool but for what I do, I don't see a need for it. I with I could weld like him. Even with steel alloys at this point.