Thermal Lancing (yikes!!)

[Richard]

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]

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]

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

 

[denchen]

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]

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]

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]

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]

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]

.............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.

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]

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.