need advice about how to cut 36" metal pipe

[rbtjr]

This is not about welding but I would appreciate some advice. We have two 36" 20' long metal pipes side by side in a creek. The pipes are covered with about 2-3' of dirt to make a bridge. The creek is dry now but after a heavy rain both pipes are needed to carry the water flow. The end of one of the pipes was bent recently during some logging work. At the end of the pipe, the bend is severe enough so that only about 1/4th of the pipe is open. I uncovered the last foot or so of the pipe and tried using a hydraulic jack to see if I could open up the bent end but that didn't work. It looks like I will need to remove the dirt to expose the top of the last 3' the pipe and cut out the bent section on the end. I have never used a metal cutting torch. I am willing to rent a torch or buy an inexpensive torch. Does anyone have a recommendation about what kind of metal-cutting torch would work best for a beginner for my application? Thanks in advance for the feedback.

 

[LD1]

One of those oxy-acetelyene back-pack type torches should do the trick.

You didnt say how thick the pipe is though?

 

[rbtjr]

One of those oxy-acetelyene back-pack type torches should do the trick.

You didnt say how thick the pipe is though?

I don't know exactly how thick the pipe is and I am not near it right now so I can't measure it. I would guess that it is no more than 1/4" thick.

 

[BIG DOOLEY]

you could try horizontal cuts or cuts parrallel with the pipe and then the hydraulic jack.
a series of cuts will reduce the amount of pipe you are trying to move at one time.
you can also cut and bend shorter sections at a time not the entire length in one move.
you may be more apt to straighten it and weld it back together when done?
just an idea
Tom

 

[Car Doc]

That sounds like it will need a pretty big torch and then you plan on welding the section back in or leave it out? Arc welding gouging rods can be used on a 150-200 amp welder to cut steel if you have portable power and a welder available.

The welder then could be used to fix the bad section by welding a new chunk in after its cut out just thinking out loud. Fire hazard also comes to mind but its your eyes on the project you know what the risk is. hth

 

[rbtjr]

you could try horizontal cuts or cuts parrallel with the pipe and then the hydraulic jack.
a series of cuts will reduce the amount of pipe you are trying to move at one time.
you can also cut and bend shorter sections at a time not the entire length in one move.
you may be more apt to straighten it and weld it back together when done?
just an idea
Tom

Good idea. I was thinking of entirely cutting out the bent part, since I didn't succeed in forcing it back out with the jack. But if I were to cut the pipe in a few places parallel to the length of the pipe, I might could use the jack (or maybe even a short-handled sledge hammer) to force most of the pipe back open. Once I get the pipe open, if I haven't cut out the top section to remove the bad part, I could put something with some strength over the top of the pipe, and then cover it back up with dirt so that the bridge would not be made more narrow. But I am less concerned with making the bridge more narrow than I am with opening the pipe to handle more water flow. Thanks for the ideas.

 

[rbtjr]

That sounds like it will need a pretty big torch and then you plan on welding the section back in or leave it out? Arc welding gouging rods can be used on a 150-200 amp welder to cut steel if you have portable power and a welder available.

The welder then could be used to fix the bad section by welding a new chunk in after its cut out just thinking out loud. Fire hazard also comes to mind but its your eyes on the project you know what the risk is. hth

No electrical power is near the pipe. There would be some fire risk but not much, and I could have some help nearby with a fire extinguisher. I do not have access to a welder and I have never used one, so I don't have a feel for the size of a 150-200 amp welder. What kind of power source is needed for a welder of that size? 220 volt? And if so, what amperage? Thanks for the feedback. I am getting interested in the idea of cutting the pipe to reshape it and then welding back either the pipe or something to replace that part of the pipe.

 

[nybirdman]

If it is galvanized culvert pipe(sprial pipe),it will be galvanized;use caution with fumes if flame cutting.Stay up wind.You may want to try a cutting wheel on a grinder if you can locate a generator.

 

[rbtjr]

If it is galvanized culvert pipe(sprial pipe),it will be galvanized;use caution with fumes if flame cutting.Stay up wind.You may want to try a cutting wheel on a grinder if you can locate a generator.

It is spiral culvert pipe but I don't think it is galvanized. I seem to remember that it is thinly coated with some corrosion-resisting material of some kind. I thought of trying a cutting wheel or a reciprocating metal saw. I have an air-powered cutting tool that I haven't used in years but I don't have either a portable compressor or a portable generator. I was looking on the Internet last night at battery-powered hand-held reciprocating saws but I didn't get far.

 

[LD1]

Yep, if it is galvanized, use caution if you torch it. It really shouldnt take a big torch if it is 1/4" or less. Even the smallest and crappiest torches I have seen would cut that no problem. Just might not be as fast as a bigger torch is all.