Thermal Lancing (yikes!!)

Richard · Jun 30, 2020

So, I've got a stuck king pin on my industrial backhoe. Couldn't get it moved to remove steering knuckle.....so it's been cut off. I now have (roughly) 1" stub on top of the axle and 1/2" stub on the bottom.

Been beating, oiling, rose-budding, welding (a lever onto the top and sledging on it) and it's still laughing at me/us.

In process of having a frame built so we can slide/hold a 30 ton bottle jack and see if we can use that to move it from the bottom up....

So, the bottle jack is our current plan.... had a friend who said I should thermal lance it. I had never heard of it and looked it up.

I have now also spoken with a company that provides/sells those tools and he (very confidently I might add) said that it should take about 30 seconds to blow a hole through the king pin, which is approximately 1 3/4" diameter and 10 inches long.

If you are as clueless to what this is as I was..... I'd urge you to do a google search and watch a video or two. If you like fireworks, it's quite impressive though, I presume it's not for the faint of heart.

Which brings me to my primary concern should this avenue be explored.

1. The pin is vertical. After seeing how the slag blows out, I don't think going down is prudent....so would want to go from bottom UP, at least I'm not staring down the throat of Mount Vesuvius.
2. Guy from company said that the rod can be bent, which is good and helps support idea of going vertical
3. Slag.... I didn't see anything after a triumphant view of a hole or a pin being removed.... may I presume that the slag that blows out of this will stick to all the metal and create little issues, to the degree I care they're there? Or, since the machine is cold, would they maybe stick, but pop off easily?
4. My real concern is melting the actual hole that HOLDS the king pin. That would be a bad day. So, if the pin is say, 1 3/4" diameter, what size hole do you target? I'd think a 1/2" type thing as the closer you get to the diameter of the king pin, the less room for error.

Thoughts??

PS: Any certifications/qualifications on buying some of these tools? (other than drinking a beer and shouting to everyone with a camera running "hey, watch THIS!")

I've not seen anything which suggests any kind of certification (which is kind of scary)

mrmikey · Jun 30, 2020

I've done a fair bit of lancing, fun/not fun. Fun to see the end result, not fun getting burnt which is almost inevitable. Wear ear plugs for sure and a dark, #7-8 or so shield.

1. The pin is vertical. After seeing how the slag blows out, I don't think going down is prudent....so would want to go from bottom UP, at least I'm not staring down the throat of Mount Vesuvius

Bottom up would work better but saying that, think about where the slag goes and protect your hand with either a piece of bodymetal or pairs of gloves. Working overhead is hard to keep everything parrallel but can be done. Horizontal is the easiest, you can see but the slag still flows/blows out.

2. Guy from company said that the rod can be bent, which is good and helps support idea of going vertical

Never seen or used a bent rod, if you did bend it, you'd have a heck of a time keeping it straight and parrallel to the pin. Not only that, but I'd be wary of the rods inside coming loose the outer sheath.

3. Slag.... I didn't see anything after a triumphant view of a hole or a pin being removed.... may I presume that the slag that blows out of this will stick to all the metal and create little issues, to the degree I care they're there? Or, since the machine is cold, would they maybe stick, but pop off easily?

There is lots and lots of slag, it won't stick to metal unless the surrounding area gets really hot which it won't. If you're on cement, put some metal on the floor or you'll end up with a badly pitted floor as well as cement pieces stuck where cement pieces shouldn't be . Make sure you're well away from flammables, outside on gravel with a hose handy is ideal.

4. My real concern is melting the actual hole that HOLDS the king pin. That would be a bad day. So, if the pin is say, 1 3/4" diameter, what size hole do you target? I'd think a 1/2" type thing as the closer you get to the diameter of the king pin, the less room for error.

An 1-3/4 pin is easy to lance, I've done them down to 1" which is tricky and have screwed up a couple of bosses I'm not ashamed to admit. Have to watch grease holes as the molten channel will follow the path of least resistance, i.e a preexisting hole. The ones I screwed up were front kingpins on an Izuzu cabover, and of course the axles were obsolete.1/2" is probably the biggest rod you'd want to go.

PS: Any certifications/qualifications on buying some of these tools? (other than drinking a beer and shouting to everyone with a camera running "hey, watch THIS!"

)
No certification required, just experience LOL. Be sure to keep your oxygen hose well away from the area and be sure to have a fire watch. Don't force the rod into the hole, if you do, it'll end up getting stuck which is a pia. If you don't have another acetylene/ox setup the get it lit, you can use a welder or a 12V battery on a striker plate, just be aware to keep the battery out of the way. Don't be tempted to get the last inch out of the rod neither once you start getting deep, suck it up and throw the last bit away.
Once the pin cools, it'll probably fall out. I've lanced out 3-4" pins on a loader and a well placed rap with a hammer once cooled and out she comes.....Mike

dstig1 · Jun 30, 2020

Pics of the king pin and surrounding would be helpful to see if there are other options to consider...

denchen · Jul 1, 2020

Many years ago I did a one day course on Kerry Cable Cutting. This gear is much like a Thermal Lance but instead of `the lance`, it has a flexible steel wire cable that has a hole running through its full length. The steel is the cutting fuel. To get the thing going, a bit of common wire wool was wrapped around the open end, oxygen was connected to the other end, 100psi [7 bar] if memory serves me right, then a small PP9 battery was applied to the wire wool, and off it went. Awesome. The idea was you kept one hand still to hold just back from the burning end, and used the other to feed the wire through as it burnt down. Sounds easy, but !!!. Anyway from what little I know, I think if you attack you pin with a lance or cable, even though it is 1 3/4 inch, you are going to damage the bushing. Heat from these things does not spread outward as fast as oxy/cet torch, but by the time you get in more the a couple of inches, you`ll be all over the place. Working upside down sounds great, but some ones going to finish up with some serious burns. Having used both lance and cable, I think they have their place, but cutting your pin out without damaging the bush...…...I had to be game for most things before I retired, but this, well good luck.

mikester · Jul 1, 2020

mrmikey said:
I've done a fair bit of lancing, fun/not fun. Fun to see the end result, not fun getting burnt which is almost inevitable. Wear ear plugs for sure and a dark, #7-8 or so shield.

Bottom up would work better but saying that, think about where the slag goes and protect your hand with either a piece of bodymetal or pairs of gloves. Working overhead is hard to keep everything parrallel but can be done. Horizontal is the easiest, you can see but the slag still flows/blows out.

Never seen or used a bent rod, if you did bend it, you'd have a heck of a time keeping it straight and parrallel to the pin. Not only that, but I'd be wary of the rods inside coming loose the outer sheath.

There is lots and lots of slag, it won't stick to metal unless the surrounding area gets really hot which it won't. If you're on cement, put some metal on the floor or you'll end up with a badly pitted floor as well as cement pieces stuck where cement pieces shouldn't be . Make sure you're well away from flammables, outside on gravel with a hose handy is ideal.

An 1-3/4 pin is easy to lance, I've done them down to 1" which is tricky and have screwed up a couple of bosses I'm not ashamed to admit. Have to watch grease holes as the molten channel will follow the path of least resistance, i.e a preexisting hole. The ones I screwed up were front kingpins on an Izuzu cabover, and of course the axles were obsolete.1/2" is probably the biggest rod you'd want to go.

)
No certification required, just experience LOL. Be sure to keep your oxygen hose well away from the area and be sure to have a fire watch. Don't force the rod into the hole, if you do, it'll end up getting stuck which is a pia. If you don't have another acetylene/ox setup the get it lit, you can use a welder or a 12V battery on a striker plate, just be aware to keep the battery out of the way. Don't be tempted to get the last inch out of the rod neither once you start getting deep, suck it up and throw the last bit away.
Once the pin cools, it'll probably fall out. I've lanced out 3-4" pins on a loader and a well placed rap with a hammer once cooled and out she comes.....Mike

Great post!

I also suggest at least wearing a helmet, leather spats, chaps and welding jacket. Having a molten ball of metal roll down the back of your shirt or into your boots will leave you a lasting impression!

mrmikey · Jul 1, 2020

Great post!

I also suggest at least wearing a helmet, leather spats, chaps and welding jacket. Having a molten ball of metal roll down the back of your shirt or into your boots will leave you a lasting impression!

Thanks Mike.
Yes, I've got the scars to prove it LOL.
Worst was 20+ years ago a piece of slag went in and burnt a hole in my ear drum, felt like the size of a brick up and hit me in the ear. My own fault, was under a tandem truck gouging a plow front off that was bent, no ear plugs. From then on if I'm outside in the winter I have to keep a hat over that ear or if I go swimmimg I have to use an ear plug. If not it'll get infected which is not pleasant. Light doesn't shine thru....yet anyways LOL
Years ago a friend of mine where i used to work was making a pipe rail 1-1/2" pipe or so, coping out the ends of the horizontal rail to fit on the posts with a torch so the cutoffs were the shape of a half moon, 'bout as big as a twonie. He never laced up his boots and always wore them outside his coveralls....you guessed it. A hot cutoff landed right on his ankle bone and actually burnt into the bone, he was off for months.
N-e-way...sorry to hijack ur post Richard, I'll shutup now

............Mike

cqaigy2 · Jul 1, 2020

Sometimes a fireman/observer is kinda handy, especially if you catch yourself, or stuff around you, on fire. Or so i've been told....

Tags · Jul 2, 2020

I致e never done any thermal lancing, but I have seen guys set up to use one, and they致e welded an angle iron on top of, or alongside of,what they are lancing to help keep the lancing rod parallel and to guide the rod through the pin.

mrmikey · Jul 2, 2020

.............and theyè‡´e welded an angle iron on top of, or alongside of,what they are lancing to help keep the lancing rod parallel and to guide the rod through the pin.

Only problem with that is once they get so far into the pin, the collar on the lance hits the angle or whatever you're using unless you have really long rods.............Mike

Birdhunter1 · Jul 2, 2020

I've never used a thermal lance, I've seen one being used I decided to never do it without ALL of the proper gear. I find repair work like this easier and safer to drop the part off at a heavy duty truck shop or a machine shop and have them remove the stuck pin. It will cost much less to do this than to even begin to get the right PPE.

Richard · Jul 2, 2020

dstig1 said:
Pics of the king pin and surrounding would be helpful to see if there are other options to consider...

Didn't think about a picture.

As a preface, our current project is to have a cradle made (being done now) that will hold a 30 ton bottle jack and put the jack on the bottom part of the pin and see if we can then push it out or at least break the bond.

The lance thing is in my view, the last last resort.

The pin has been cut on the top AND the bottom so I don't have any choice, it must come out.

Richard · Jul 2, 2020

PS: Don't let the little jack stand make you nervous. It was only used to help keep the axle from bouncing while being pummeled with a sledge.

Richard · Jul 2, 2020

I don't care about the bushings and bearing, all those are going to be replaced.

Now, down the hole where the pin resides is a horizontal hole. This is where a slanted "cotter pin bolt" goes through to lock the pin in place. So this would be a possible place for slag to flow if it got exposed to the lava.

Richard · Jul 2, 2020

Just found out the cradle might be ready soon.....I'm hoping this weekend.

I don't know how, I don't know when, but I DO know that this pin is going to come out.

If I am anything I'm persistent. My wife calls me her little bulldog because I get focused and 100% determined.

mrmikey · Jul 2, 2020

So this would be a possible place for slag to flow if it got exposed to the lava.

Be aware of what I said previously, the burn hole will follow the path of least resistance. Not just slag will flow out but oxygen as well which will burn along the hole. If you see slag coming out the bolt hole.....stop.........Mike

Richard · Jul 2, 2020

If it comes to this process..... would it be fair to think that (qualifier) "as long as the rod was well centered" then the sides of the pin would (should) maintain staying intact and help prevent any side slag shows??

Richard · Jul 2, 2020

For anyone not familiar with this.... the rod goes through the axle. The hole you see opens up to a "notch" in the rod and a slanted cotter pin goes through there and bolts on back side to hold everything in.

Picture attached shows new rod with notch and upper left, shows the tapered cotter pin with nut.

The two meet up inside the hole you see in the earlier picture.

mrmikey · Jul 2, 2020

I misunderstood your description. I was thinking a hole thru the pin. You'll be fine as long as you stay in the center or at least close to center as you can.......M

wdchyd · Jul 2, 2020

As a last resort before Oxy-lance, I’d try a 90# jack hammer one last time. If not the Oxy-lance will work fine. You’ll need at least two fire watch/spotters cuz that fire coming out will seem like fire and brimstone on a stick. You’ll need full face shield, leathers, thick welding gloves and possibly a few fire blankets wouldn’t hurt.
When you first start up the torch the torch man will only be able to see how straight in one direction, have other person at 90 degrees watch from the other angle and guide you while burning. Turn up the oxygen to 90-100 psi and have at it.

Oh yea, make sure you have several extinguishers and a good running water hose just in case. While burning In the center of pin keep the outside housing/axle cooled with water and after you’ve poked a whole from both sides let the pin cool slowly on its own. It will shrink in the housing by itself.

And yes, I have done this many times, but only after slugging away with no movement of the pin.