Acetylene torch bad practice?

[murphaayyy]

At my first day of work today there was a car with stuck tie rod nuts that no one could seem to get free (im manager in training). I asked the store manger if there was an acetylene torch and he said it is bad and weakens the tie rods. He brought me to the master tech and he said yea, it changes the molecules or molecular composition or something and it weakens the metal. The manager then said, wow i can't believe merchants (where I used to work) still uses it, like its some old or bad practice. I didn't say a thing because I knew it was not the time to 'be smart'.

When I was a technician I used the torch a good bit on tie rods as sometimes it was impossible to turn the nuts, even with nice locking screw ring pipe wrenches that get tons of leverage. But also on exhausts where the bolts looked like nubs that could just be blasted clean with the torch saving both parts. My one coworker always told me to warm exhaust studs with the torch then let them cool, to extract and contract to break rust. I feel like the torch was good practice if used right.. Was I wrong, and taught bad practice? How do people work with out a torch?

 

[CWP1616L]

If the metal you're heating is allowed to cool at room temperature, it won't affect the heat treatment.

To make the metal harder, it is quenched in either water or oil after being heated to the critical temperature.

To make the metal softer, it is cooled slowly in an oven.

 

[murphaayyy]

lol, so your argument is there is little to no effect if i cooled them at normal shop temp.. at least I know I wasn't doing it bad.

 

[blacK20]

I live in an area where winters can get a little ugly and rust buckets are very common. The flaming wrench is an essential tool here. Just curious... what was the "master tech" and "managers" advice to your problem without using the torch? Obviously they had a better idea.

 

[Ruger_556]

We were taught how to disassemble tie rods with an oxy acetylene rig at the tech college so... Tie rods are good steel but I don't think they're even heat treated. Without a torch their are many things you just can not do.

 

[Buckgnarly]

I live in an area where winters can get a little ugly and rust buckets are very common. The flaming wrench is an essential tool here. Just curious... what was the "master tech" and "managers" advice to your problem without using the torch? Obviously they had a better idea.

X2, living in New England the blue wrench is my best friend. Was the alternative all new parts by chnance?

 

[BearCuda]

I've used a map gas torch for years on alignment jobs. Have heard that it's ok as long as you don't get parts cherry red. Don't know if that's true or not. Have also heard that it's bad to do, but like others stated you just have to a lot of times. I just talked my boss into getting a mini ductor to replace the torch. We just got it a few days ago. Haven't had time to try it out yet, but I hear they're awesome.

 

[blacK20]

Mechanics across the globe have been using the torch on cars for ages. There may be some truth to their opinion but I have personally never seen a vehicle come back due to metal failures after using the torch on said vehicle. Use it mindfully and this will become the most versatile tool in any techs arsenal.

 

[GTA Matt]

What did they want to do, replace the whole rack because of a frozen jam nut Heating up the nut won't put that much heat into the rest of the tie rod.

 

[GreenLBZ]

If you're just heating/cutting the parts you're going to scrap, go for it. If you're heating something that stays on the car, then no.

 

[murphaayyy]

I live in an area where winters can get a little ugly and rust buckets are very common. The flaming wrench is an essential tool here. Just curious... what was the "master tech" and "managers" advice to your problem without using the torch? Obviously they had a better idea.

lol not my problem, im a manager in training, i used to work as a tech. they thought replacing the part was good practice.

I've used a map gas torch for years on alignment jobs. Have heard that it's ok as long as you don't get parts cherry red. Don't know if that's true or not. Have also heard that it's bad to do, but like others stated you just have to a lot of times. I just talked my boss into getting a mini ductor to replace the torch. We just got it a few days ago. Haven't had time to try it out yet, but I hear they're awesome.

that mini ductor looks cool. the snap on man tried to sell me some heater device for a bunch of money. they do look fun to use, but in the video they got they show the torch being used wrong.

good to hear people thinking the torch is safe practice if used right.

 

[Farmall450]

I've used a map gas torch for years on alignment jobs. Have heard that it's ok as long as you don't get parts cherry red. Don't know if that's true or not. Have also heard that it's bad to do, but like others stated you just have to a lot of times. I just talked my boss into getting a mini ductor to replace the torch. We just got it a few days ago. Haven't had time to try it out yet, but I hear they're awesome.

My school has a death ray (mini ductor) and yeah, awesome's a good word for them.

 

[MBeaty]

If the metal you're heating is allowed to cool at room temperature, it won't affect the heat treatment.

To make the metal harder, it is quenched in either water or oil after being heated to the critical temperature.

To make the metal softer, it is cooled slowly in an oven.

This is only partially correct. If the metal was hardened at all and was heated enough then allowed to air cool, It will basically be annealed and the hardness will be lost. Both time and temperature are critical with heat treatment. Molecular changes, unseen to the eye can have profound changes on the materials physical properties.

If the part came from the factory in an annealed state, than I agree there would be less chance of altering its properties.

 

[Heavy tech]

When I went to tech they preached this. When the instructor was asked what alternative there was, he conceded that sometimes you have no choice.

Does it weaken the metal? Yeah, probably.
Will it ever cause a part to fail and cause an accident? I'd bet the chances are less than 1 in 1 million. The only tie rod I ever saw fail, anywhere other than the ball and socket joint was designed to shear, as to protect other parts of the steering system. but in today's world, companies check into liability before taking a chit.



Sent from my iPhone using Tapatalk

 

[Fireball027]

What did they want to do, replace the whole rack because of a frozen jam nut

And what happens if you can't get the nut off the tie rod end... Explain to the customer they must replace their car because the tie rod end is just spinning.

 

[skiingman]

As someone who has had a brand new balljoint break in half leading to an unscheduled trip into a front yard, I can see why a big retail car service place would be wary of altering the hardness/strength of critical suspension parts which certainly is likely to happen if you heat them much with a hot torch. OTOH, I know the manufacturers are all trying to save weight but I hope none of them are making the tie rods race car light so that they depend on perfect metallurgy and condition. That'd be bad for those of us who drive old cars in the rust belt. For sure.

Common sense has to come into play somewhere. If you just heat the nut a bit and it comes free and everything is in good shape otherwise, that seems like you say a billion to one likely to be safe. But if you have to heat the whole tie rod cherry and you're beating on things and what not to get them to move, it seems pretty wise to replace the inner and outer. That seems like 100 bucks of cheap insurance to me. I know many people bringing cars in for service are cheap, but steering is kinda important.

 

[andywander]

If the metal you're heating is allowed to cool at room temperature, it won't affect the heat treatment.

To make the metal harder, it is quenched in either water or oil after being heated to the critical temperature.

To make the metal softer, it is cooled slowly in an oven.

Umm-that really depends on what the metal is, what it's current state of heat treatment is, and how hot you get it......

 

[00S4Boy]

Both your master tech and manager's are asshats. I bet they think parking brakes have hydraulics too.

Torch the jam nut torch the outer, do your alignment and be done.

 

[zkling]

It is one of those things that more than likely started out as a liability thing and people took it overboard and just went with it. It made enough sense for people to not question them on it, especially if the "lead" says so. It is amazing how people will just accept things at face value. You should have ask why, then why again. If they can't give you a good explination well, there is your answer. However be forewarned I've noticed lots of people in a technical field get pissy when questioned like this.

 

[t100]

there are 2 sides of the story.

Properly heating up the jam nut rapidly with Oxy/Act flame doesn't put much heat on the surrounding parts. the thermal expansion and contraction breaks the rusty(or welded) jam nut.

done improperly, which puts too much heat on the parts for too long, will anneal the steel, and damage the oil seals.

FYI, annealing is the process which makes metal softer, revers of heat treatment hardening, temper.

 

[Bigplum]

It's a good way to jack up the bill by fitting a load of unnecessary new parts and a good way to piss off a lot of customers* too, I guess I must be unaware of all the accidents caused by heating nuts on steering racks leading to failure


* I'd put money on the sort of customers that get that treatment too , women , daft young men & office types .

 

[Adam.C]

If the owner got into an accident that caused an injury (or worse hurt someone else) and the accident could be traced to a broken link, you better believe the injured party would sue the car manufacturer.

If that manufacturer could show the point of failure was caused by a repair shop that did an "improper repair" to save the customer a couple $100 (unbeknownst to the customer and at the cost of his/her safety), that would be bad for the shop owner, manager, the tech, and the master tech, all of whom could be held criminally liable.

I don't think it matters whether the link was heated enough to affect it's temper. In the end, the master tech was right. Heating parts can cause unseen molecular changes.

In my mind, it might be okay to heat muffler parts, but not suspension or steering.

 

[Kracin]

If the metal you're heating is allowed to cool at room temperature, it won't affect the heat treatment.

To make the metal harder, it is quenched in either water or oil after being heated to the critical temperature.

To make the metal softer, it is cooled slowly in an oven.

completely subjective and mostly false.

heating metal beyond it's annealed temperature can and will ruin the hardening it went through unless it goes through the same process again.

some metals are quenched then reheated and slowly cooled,

some are heated to near melting for a half hour, then brought down to only 1200ish degrees for another 15 minutes before being allowed to cool down to room temp INSIDE THE OVEN they were heated in which can take hours.


you can and will ruin temper on a hardened metal by heating it red hot and letting it cool room temperature that quickly. can you get by doing it, sure, but the metal will not be the same.



and i hate it when people see the ole "red hot sword quenched in water" making an indestructable sword.. there are about 20 other steps going on before and after that, and simply quenching something causes it to become much more brittle. i hated it when i would make a production too for somebody in my old plant, and the first thing they did after i brought it out and said "careful its real hot still, just got done welding it". they throw it in a bucket of water, and when questioned about it, they bring up the old TV quenching sword thing. and then the damn tool breaks about 20 minutes later because they destroyed the integrity of the weld

 

[Aquaticbob]

If the owner got into an accident that caused an injury (or worse hurt someone else) and the accident could be traced to a broken link, you better believe the injured party would sue the car manufacturer.

If that manufacturer could show the point of failure was caused by a repair shop that did an "improper repair" to save the customer a couple $100 (unbeknownst to the customer and at the cost of his/her safety), that would be bad for the shop owner, manager, the tech, and the master tech, all of whom could be held criminally liable.

I don't think it matters whether the link was heated enough to affect it's temper. In the end, the master tech was right. Heating parts can cause unseen molecular changes.

In my mind, it might be okay to heat muffler parts, but not suspension or steering.

I would say a manufacturer is going to settle before it gets to this point, even if it were to become an issue. Suing the manufacturer is never a good starting point in the situation where you believe a tie rod end failed and caused the crash. It would be incredibly hard to prove any of this, not to mention the costs associated with it, plus the time. Just the lawyer fees for the litigation would be in the hundreds of thousands, not to even get into court fees, and multiple testing procedures, and what not.

I would say go ahead and use the torch, I know many mechanics who use it and haven't had a single problem. I even believe a local stealership's procedure for tough bolts is to break out the torch.

 

[Bigplum]

So it's ok to heat exhaust parts ? What if the heated part failed , caused a accident , then people started law suits against improper repairs and everybody gets sent to jail.....

Safest bet is to buy a new car with no service items , maybe with a sealed fuel tank from the factory so there's no chance of improper fuelling that could lead to law suits

 

[Danglerb]

Legally the safest action is to follow manufacturers recommendations.

Are the parts hardened or annealed when new?

Do with "work harden" in use so annealing restores them?

Maybe just split the nut?

Could be too people who "know how to do it" are using a torch wrong, so shop says nobody uses a torch.

 

[Heavy tech]

If we're talking about a tie rod jam nut, why couldn't it be heard to get it apart, then throw that nut to hell. Put a new one on. problem solved


Sent from my iPhone using Tapatalk

 

[MBeaty]

So it's ok to heat exhaust parts ? What if the heated part failed , caused a accident , then people started law suits against improper repairs and everybody gets sent to jail.....

Safest bet is to buy a new car with no service items , maybe with a sealed fuel tank from the factory so there's no chance of improper fuelling that could lead to law suits

This is not what anyone where is trying to imply. One must be careful when adding heat to structural or threaded components. Depending on what state the component came from the factory in as well as its carbon content, serious metallurgical changes can undergo when it is heated.

Something like an ehaust system is not structural and does not control a function as critical as a cars steering system. Also, most exhaust tubing would be shipped in the annealed (softened) state so it can easily be bent and welded. Not to mention that it lacks the carbon content to be able to be accidental hardened to a significant degree.

Quick heat applied just to a stuck part does work to remove stuck parts, but depending on the parts, I do not think that all should be reused after being heated. Heat treatment is finicky at best even under controlled conditions and a torch is definitely not very controlled, so one must be careful.

 

[arms1970]

Both your master tech and manager's are asshats. I bet they think parking brakes have hydraulics too.

Torch the jam nut torch the outer, do your alignment and be done.

BAM....Done....

 

[sberry]

Heat it and beat it.

 

[Bigplum]

Nuts are better roasted

 

[firebox40dash5]

OP, being as I work about 10 miles from you, there's no way in hell I'd be able to get half my work done without the Victor wrench. I'd be spending my whole day drilling and extracting fasteners, and getting telephonically reamed by customers who were pissed about their bill.

I couldn't tell you if what you were told is true or false. I'm betting the ones who told you it couldn't either. I generally try not to torch on **** that's not getting replaced, but sometimes it's gotta get done. They'd probably ***t a brick watching me turn a nutsert cherry red next to a plastic fuel tank to do a fuel pump.

Specifically in the case of tie rod ends, I think they're idiots... or you got a job at a Brooks-Huff location. On R&P ends, the part I'm turning red is the jam nut, and maybe the outer end itself. Obviously I can't get the whole outer that hot without melting the boot and damaging the socket, so I don't.... but the jam nut is getting replaced either way. Hell, most inner AND outer ends come with a new nut. I'm not going to claim to be a metallurgist here, but I really doubt that I'm putting that much heat on the inner TRE threads when I'm doing that, so I'm not seeing a problem.

 

[bobcatdan]

I was taught never heat suspension parts which I was took as the cast iron knunckle. Putting a little heat to a tie rod jam nut is not going to hurt anything.

 

[Perrorojo]

What makes the most money for the shop?

I really believe we're going to watch tech's become $10/hr assemblers as automobiles continue to become desposable appliances. Fear of legal action is going to drive the troubleshooters and mechanics away.

We're talking about using a torch to loosen a stuck "insert part here". I think my dad taught me the virtues of Hot wrench when I was 5. "Just don't set the shop on fire" was the content of the safety meeting we had.

 

[Dirty Diesels]

What makes the most money for the shop?

I really believe we're going to watch tech's become $10/hr assemblers as automobiles continue to become desposable appliances. Fear of legal action is going to drive the troubleshooters and mechanics away.

We're talking about using a torch to loosen a stuck "insert part here". I think my dad taught me the virtues of Hot wrench when I was 5. "Just don't set the shop on fire" was the content of the safety meeting we had.

I agree, the hot spanner used properly always gets the job done.

 

[reptilezs]

once you heat up steel to the tempering temperature the heat treat can change. tempering temps are usually around 400f. the steel must also be the correct alloy such as high carbon. mild steel wont take a heat treat really. tie rods are heat treated to some extent at least the ball socket and ball.

 

[justanengineer]

JMHO, but Ive seen the torch used improperly more often than not, so personally Id suggest others break out the nut splitter, hacksaw, or sawzall and would only use the torch myself as a last resort. Sorry, but theres just too dam many plastic, rubber, or paper thin Chinese metal parts today.

 

[redwrench60]

I knew this thread would bring out the inner metallurgist in everybody. Quickly and carefully heating (or cutting) components and hardware is a time honored technique for disassembling repairable assemblies in nearly all trades. Obviously good judgement and common sense come into play when it comes to the gas axe. This usually falls to the Foreman or the more experienced techs in the shop; the younger guys know to ask for help from the guys who know what's safe and appropriate to the task.

Simple fact of the matter is sometimes things are happy where they're at and the only way to get something apart is with the redwrenchand I've saved customers untold thousands of dollars with one. The alternative is to scrap everything that puts up any resistance; then the 'stealership' comments would get real bad!

 

[skruft]

I have never heard of anything wrong with using a torch for this purpose. Personally I try first with a MAPP or air-acetylene torch and I find that is usually enough. Or if the problem is an exposed nut, I may get it off with a nut-cracker and use a new nut.

 

[dimensionseven]

i was taught in tech school not to do this, as an alternative, we had a car that had this issue, we separated the outer tie rod from the knuckle, twsited the outer off. then held the inner with a wrench and used an impact gun on the nut. after getting it off to coat the threads with anti seize.

this seemed to of work for me. i guess the torch would work because it doesn't take a whole lot of heat to get it moving again. if over heated i could see where it would be detrimental.