straight cut on pipe

[RuffneckDave]

probably simple for most, but how to get a straight cut on pipe thats already been cut on. both ends have been rough cut.

i know a wrap round but talking straight enough to bevel and fit. and larger 10" + pipe.
i could see using several torpedo levels and a framing square.
love to hear from the pros.

thanks

dave

[Warpspeed]

Up to about three inch, a worm drive radiator hose clamp tightens up quite square. For very much larger pipe, I have no idea.

[MoroneysWelding]

In the field or in the shop?? I have done stuff like wrap the pipe with a tig filler rod and tacking it in place, in the field and also stuff like wraping them with a pipe layout roll. But in the shop I just use the good old horizontal band saw.

[ExpatWelder]

A 6-8" wide pipe wrap is going to be dang near as straight and precise as any instrument, square, levels or whatever you can think of for getting a straight line, then it's up to you to cut it and bevel it.

[leightrepairs]

Pipe wrap will put a nice straight line.

[BD1]

Originally Posted by leightrepairs

Pipe wrap will put a nice straight line.

Yea, wrap a round and practice. All we use is a hand held ox/act torch. Practice and more practice. Been doing it for 40 years, just wrap and cut .

[idacal]

if your doing a bunch of cuts on one size of pipe these help take out the shake http://www.americawestdrillingsupply...orchguides.asp

[violatedppl]

wrap around, soap stone and patience to get it right the first time.

[Doug247]

i made a ring once that was a little larger than the pipe, it could be slipped over and then secured in place with three evenly spaced bolts that were threaded through nuts i had tacked to the ring. Then used the torch to cut it by draggign the torch on the ring following a line i drew with a wrap around or a magnetic tape.

[pipefitter72]

wrap-a-round is the way to go..if you are going to cut a bevel dont' forget to make your mark about 1/8 short to allow for the bevel.

[anickode]

I was just thinking about this subject... It occurred to me that perhaps a length of motorcycle chain would work well.

[jpfabricator]

You can use a length of masons twine to take the place of a wrap around. This method is also the wastest way to wrap around a pipe fitting that needs to be marked for a miter cut.

[anickode]

Originally Posted by jpfabricator

You can use a length of masons twine to take the place of a wrap around. This method is also the wastest way to wrap around a pipe fitting that needs to be marked for a miter cut.

Seems to me that string, by nature of being string, would be less ideal for marking a straight line on a pipe since it has the ability to bend in 2 axes, not just one.

[farmall]

Another vote for wraparound or a strip of emery cloth (which makes any size wrap you like and is great for sharpening your soap stone).

Ensure you get a "double wrap" because when wraparound lines up on itself it is straight. Keep it snug.

That's what I used to mark hundreds of pipe coupons where I worked for manual torch cutting. It's fast and easy.

To rotate the pipe while it's on jackstands, take a pipe wrench and run the jaws down so they are a bit loose on one wall of the pipe when slid on from the end. When you pull the pipe wrench they will catch and grab nicely. Go slowly!

[drjuan]

Originally Posted by farmall

Another vote for wraparound or a strip of emery cloth (which makes any size wrap you like and is great for sharpening your soap stone).

Ensure you get a "double wrap" because when wraparound lines up on itself it is straight. Keep it snug.

That's what I used to mark hundreds of pipe coupons where I worked for manual torch cutting. It's fast and easy.

To rotate the pipe while it's on jackstands, take a pipe wrench and run the jaws down so they are a bit loose on one wall of the pipe when slid on from the end. When you pull the pipe wrench they will catch and grab nicely. Go slowly!

2 X on what farmall said, plus what I have done when no wrap is available is cut another pipe the next size larger on the band saw, split it with a torch and use large hose clamps to secure both halves and mark my cut, ( or actually use it as a guide for the torch head )

[Fat Bastard]

Pipe beveler cuts to length and cuts the bevel.

[60redfacer]

Ive been fabricating, fitting, and welding the round stuff (pipe), for about 15 years now and I use a wrap-a-round to make a good square line, just my 2 cents

[farmall]

BTW, wraparounds are made of quality gasket material, worth remembering if you need a gasket in an emergency or if you need a small wraparound and have gasket material handy.

[mb_welder]

emiry cloth also works in a pinch for marking a straight cut on pipe!

[old mate]

i've had success with shorter sections of large diameter pipe that are rough cut and need to be squared up......put it on a bench with the rough end down and square it to the bench with wedges or tack welds and then hold your chalk flat on a piece of box section and mark a line around the pipe above the rough cut.....

[hobohilton]

BIG INCH Wrap around -

#179B Curv-O-Mark® Wrap-A-Rounds Ex. Large 9'

[Gerry1964]

Sounds strange but i've used a roll of wall paper before, The tube was about 36" in dia, Just wrap the paper round until it meets and chalk a line around the edge

[Fat Bastard]

I use the hoist to lift it into the saw and let the saw do the cutting while I go make coffee.

[hobohilton]

Originally Posted by Gerry1964

Sounds strange but i've used a roll of wall paper before, The tube was about 36" in dia, Just wrap the paper round until it meets and chalk a line around the edge

----------------

When your a welder, you have to think outside the box. Different things I've used when no "Wrap-A-Round" was available --- My belt, a roll of emery cloth, card board box, backing card board from a head gasket set, newspaper, string, and the list goes on..........

Thanks,

Hobo

[handtpipeline]

I'm really amazed at how many people and even decent size fabrication companies that hand cut/ bevel pipe. I understand if you don't need a perfect cut, or only do a handfull of cuts a year, but I just can't imagine doing it on a daily basis without a beveling machine. It is a very good skill to have, to be able to hand cut and bevel, but from a production standpoint, it just doesn't make sense to me. I have beveling machines to handle 2" to 26", and if I'm working on pipe, I'm using one... I also have a motorized band beveling setup with larger bands than that, but have never used it. I think I have up to a 48" band for it. We bought that whole setup at an auction, and have never messed with it.