Best way to cut pipe at an angle?

[bdog]

I have 2-7/8” oilfield pipe set vertically in the ground for a shed. It is already concreted in the ground. I need to cut the tops off at desired height with a 2/12 (9.5 degree) angle so I can weld the I beam for the rafter resting on top of the pipes.

I have one of those gadgets that slips over the pipe to mark a saddle, straight cut, or 45 degree cut but how do I go about making a 9.5 degree cut on the pipe?

 

[monkeyduster]

Here is a web site that has a large number of calculators and printable patterns that might help.

www.blocklayer.com
Go to "Printable Templates" then "Pipe Notching Templates"

 

[bcp]

Maybe this will work.

On a scrap pipe, cut a 9.5 degree angle on a bandsaw. Then wrap it with light cardboard/stiff paper and trace the end. Cut off the part not wrapped around the pipe. Mark the high and low spots. Use this pattern to mark your standing pipes.

Bruce

 

[spitter]

Pipe fitter's handbook has all the proper formulas to layout angles on pipe. And a good wraparound. There are some good videos on UT they could explain it a whole hell of a lot better than I could.

 

[square1]

What tool (s) do you have to make the cut? Porta-band?
Build a jig that clamps / bolts to the pipe or to the porta-band to use as a guide
I have a 45⁰ & 22 1/2⁰ jig built so I don't have to mess with measuring / marking, etc...
Unfortunately they're in my storage unit 100+ miles away or I'd snap a pic & post it for you

 

[workinonit]

Porta-band and/or a Metabo. I'm making the assuption you already know how to calculate the angle and mark it.

 

[LD1]

The angle cut from high side to low side is a little less than 1/2".

Not knowing the tools you have at your disposal or what the method of choice for welding is....I'd probably just eyeball it close with a sawzall....fine tune with a grinder to desired angle. Its welding, not finish carpentry. So the joint dont have to be perfect for a good weld to follow

 

[Egon]

Just a piece of paper and mark out the angle using Tan tables. Then wrap it around the pipe for marking.

 

[bdog]

Thanks for the replies. I guess my issue is making the mark more than anything. I plan on making the cut with a torch. I can calculate vertically where the marks need to be. If say for example I was working with square tubing and not pipe I could make my marks and use a square to transfer them around to all sides of the square tubing. I am not sure how to do this with pipe.

As LD1 mentioned the difference is heights across the pipe is only roughly 1/2” but still if cut incorrectly that is a rather large gap to fill when welding in the overhead position. I also need to be able to balance a large heavy I beam on top of these cut posts so if the cut is wrong it is going to be very unstable while I am trying to weld it up there.

I am not sure what the “tan tables” you are referring to are Egon?

Monkey duster the block layer site is very cool and has a lot of information but the pipe notching templates I saw were all for pitting pipe to pipe. I need a simple angle cut to fit a pipe to a straight surface.

Bcp I like your idea and think something along those lines would work. This seems similar to what square1 suggested except manually marking it instead of building a jig.

 

[LD1]

2-7/8 od pipe has a circumference of 9"

Draw a triangle on a piece of paper ....9" base with 1/2" height.

Cut it out, wrap it around the pipe. It will get you close enough for torch work.

Or find something round and easy to cut an angle on with a bandsaw or meiter saw. Ironically.....just finished some leftover pizza for lunch and the grated parmesan cheese container is round, plastic, and right at 3" diameter. Would make a PERFECT template. Cut on angle....slip down over pipe and mark.