Carbon arc gouging

[F.J.]

One of my customers has two jcb tele handler's and a pin on one of their stabilising legs has seized, we've tried using a 35 ton hollow jack on it but it just keeps tearing the top of pin off so gouging was brought up. Ive heard of it but never seen it being done so was wondering if anyone can shed some light on the kind of equipment I will need and the process used to get the pin out with out damaging the leg. JCB have told my customer that all they do is cut the leg off and replace it but at £750 each he isnt too keen on that idea.

Thanks

 

[wyn]

I've seen pivot pins on loading shovels removed with a thermic lance.

They were about a foot long and 6 inch diameter.....burnt the centre out then cooled with water and they came out fairly easily.


If you can't pull the pin can you push it....cut a "U" shape out of some lumpy steel plate...big enough for the jack to fit inside....weld it over the centre line of the pin and use spacers along with the jack.

 

[blenkie1]

How long is the pin can it not be burned out? Think I would be trying what Wyn says.

 

[Jim Davey]

Thermic lance is the tool for the job, it makes mincemeat of a 60mm pin in seconds. The cost of the setup is in the region of a grand. That's sticks, hoses and gun.
As said, blow through the middle of the pin, quench, knock out, easy. It's a nasty process though, you need to be well suited up in leathers to protect yourself from the inevitable blowback that comes from gouging into a blind hole.

 

[Spark plug]

Could you not drill it. I drilled a 45mm hole through the king pin on my tractor to get it out the front axle.

 

[J.B. Welding]

It's possible to heat the pin sleeve till its all cherry red then quench it with water. The complete pin will then be extractable. You can use oxy-pro and a torch so long as the sleeve is gettable at (it might take a while). A lance will work but the chance of gashing up the surrounding area of the pin and the inside of the bushing must be quite high on your first go! Is it just seized or is there a step on the pin?

 

[F.J.]

It's possible to heat the pin sleeve till its all cherry red then quench it with water. The complete pin will then be extractable. You can use oxy-pro and a torch so long as the sleeve is gettable at (it might take a while). A lance will work but the chance of gashing up the surrounding area of the pin and the inside of the bushing must be quite high on your first go! Is it just seized or is there a step on the pin?

Im not sure if theres a step on the pin as I haven't seen the new one to compare but I did think of heating the out side and smacking the hell out of the pin in the hope of shifting it. I did also consider that as I haven't done arc gouging before then there is a possibility of me cocking it up inside the sleeve so any other method would be much preferred in my opinion

 

[J.B. Welding]

The cooling is important. Red hot all around and a hose lashing water on as soon as you take the heat away, then it won't shrink back on the pin too much. A rose type heating torch is better that a cutting torch if you can get one. Best of luck.

 

[Bill Edwards]

Heat it up - you aren't intending to heat the pin, just everything round it, but obviously the pin will get very hot. Then cool it down with water as quickly as possible - hosepipe and buckets of water at the same time if possible. Then take the biggest hammer to hand and give it a hard hit and it'll shift.

Pushing stuff with hydraulic jacks rarely works when they are seized, you need to hit it. Cooling the whole thing quickly with water breaks the rust seal allowing it to knock out easily. Don't hit it when the pin is hot or you'll mushroom the pin and will need to be ground down to allow it to fit through the hole - this may happen when it's cold too, if you hit it enough.

Ideally use Oxy something to heat it, but if that's not available and the metal isn't too thick (and you've a suitably powerful welder) you can do the same thing by running welds round it without pausing.

Drilling is probably out of the question as it's almost guaranteed to be hardened steel, it won't drill without annealing it first.