need advice about how to cut 36" metal pipe

[LD1]

I am doubting the BH would work. A 12t press wouldnt get it, and I dont knwo many BH's woth that much force. But it is worth a shot. Just be sure to put a tire or outrigger on the pipe. Otherwise it will probabally pop it out of the ground before bending.

 

[Rob-D]

That is exactly what I was going to suggest. A backhoe should have no problem straightening that lip.
As for oxyacetylene torches, I just bought a new one (Harris brand) last week from my local welding supply. I was in asking about repairing my Victor brand gauges as they were all not working properly. For the price to fix them, I just bought an new torch kit for a tad over $200 which also had a #5 brazing tip. I had bought a #1 tip last year ($68 for a Victor brand) so this was a pretty good deal for the whole torch set. WS guy said he quit stocking Victor because they got too expensive and all the HARRIS brand parts are interchangeable with Victor.
Bottles are extra but can be rented on a monthy basis. I own my bottles and just pay for refills which to me is best because I dont use them enough. Everyone needs a oxyfuel torch on a farm. Guys with plasma rigs swear by them about how great they cut, but lets see them load it up and go out in the back 40 and cut something with them. Have to have one heck of a long extension cord and for about half of what they invested in a heavy duty plasma that can cut more than 1/4" thick material, you can have a complete torch set up with bottles and bottle buggy and can change the tip size to cut everything from thinnest sections to over 2" thick even with smallest torch. Limitations are that it only cuts steel where plasma will cut anything that an electric current will flow thru.

Mobile plasma isn't a problem. I use a genset and hook an oxy bottle up the the plasma. Most people have gensets.

 

[Rob-D]

I am doubting the BH would work. A 12t press wouldnt get it, and I dont knwo many BH's woth that much force. But it is worth a shot. Just be sure to put a tire or outrigger on the pipe. Otherwise it will probabally pop it out of the ground before bending.

You may have a point, I thinnk my bucket runs about 4 or 5k digging force.

Here's another option.
Use the BH to run an old telephone pole in the bent tube about 1/4 the way of the pole then get on the end sticking out and use the hoe or a jack to lift up on it, you get the mechanical advantage of the pole.

 

[rbtjr]

The backhoe suggestion is interesting. One issue with using the backhoe is that the bend in the pipe starts about 3' to 4' from the end of the pipe. We could hook the crushed end of the pipe with the backhoe and pull it up, but I am guessing that the result would be to bend back up the end of the pipe but not bend the pipe back up all the way to where the bend starts. I am not sure if I am being clear about this. The bend in the pipe is sort of in the shape of a shallow "V". The top of the pipe was crushed down through the center of the pipe, so that the bottom of the "V" is probably 10" or so from the bottom of the pipe. As you go back in the pipe from that end, there is less and less distance from the top of this "V" to the bottom of it, until you get to where the bend starts. I think we could hook the backhoe bucket on the bottom of the "V" at the end of the pipe and pull it up. I am not sure the entire bend will come up. But that probably falls in the category of "can't hurt and could help" so why not try? Also, if I could get inside the pipe--which I am very reluctant to do in its present condition--I could probably put a vertical steel support where the bend starts, and put on top of that support near the top of the pipe a straight piece of steel like angle iron running all the way out to the end of the pipe, and then use the backhoe bucket to raise the end of the angle iron. That would tend to put upward force all along the bend. Or something like that. It certainly can't hurt to try the backhoe, and we will be using it to uncover more of the pipe anyway. Thanks for the idea.

 

[rbtjr]

You may have a point, I thinnk my bucket runs about 4 or 5k digging force.

Here's another option.
Use the BH to run an old telephone pole in the bent tube about 1/4 the way of the pole then get on the end sticking out and use the hoe or a jack to lift up on it, you get the mechanical advantage of the pole.

That is another interesting possibility. That is sort of the reverse of what I noted above--using a piece of angle iron to apply force all along the bend in the pipe. As to using mechanical advantage, though, we could set that up initially by using a stout 6' pry bar or wrecking bar placed under the bend at the end of the pipe, sticking into the bit say 1', but protruding out of the end of the pipe far enough to create some leverage, and then use the backhoe bucket to raise the outside end of the bar. As you correct the bend and move farther into the pipe with the bar, you would lose your mechanical advantage as you go, but presumably after some success.

 

[bcp]

I think I would buy or borrow a hydraulic cylinder whose bore & stroke would be enough to do the job with one push, and use it for a jack.

Something like this, but with the cylinder inside the pipe:
http://dart.arc.nasa.gov/Rescue/CSRC-2008/day2/DSC04304.html

Bruce

 

[Gary Fowler]

Gonna await the outcome of this tale. A backhoe should be able to straighten a standard culvert. The OP didnt say that his jack wouldnt bend it,just that it sprang back each time. With the back hoe you can bend it far enough to allow for spring back. Once it is opened up a bit, inserting a big strong pry bar, or pipe or what ever the OP has that wont bend or break and lifting it with the backhoe should open it up.
He still has the option of splitting it with a torch and then prying it back out to original shape.

 

[rbtjr]

My neighbor who has the backhoe also has a cutting torch. I'm going to buy a big pry bar--have been wanting one anyway. Looks like we'll try the backhoe tact on Friday. I'll post the results.

 

[Reyer Farms]

The cutting torch is great tool but the skill in cutting galv. thin gauge is tricky. Then dirt and mud also make it tough. I am not saying it would not work just transport of bottles and time is a lot. Plasma cutters are for the shop or deep pockets. I think the fastest way to cut is sawzall with Lenox gold metal blades. I have no stake in the company but the blades are the best and fastest. The generator is easier to haul than bottles and you will be through faster.
By the way my welding truck has been in some the roughest backwoods in Ms, La, and Ar. If you called me to cut it this what I would do with all the tools available right there. Good luck!!

 

[tungularafishcamp]

I think Cnc Dan was on the right track with the 2 jacks but as you get it straight but before you release the jacks put a little heat( like a weed burner) to set it then release the jack and move to next section, so on. I think you would have better luck starting from the inside and working out if possible. Good luck!