Best way to un-weld pipe? FAQ

Cutting torch. Sawzall with a metal-cutting blade. Take your pick.

No, no, no, silly. Turn it on a lathe, of course. Stop just short of the zinc plating.

You could get most of it off quite quickly with a plasma cutter or O/A torch. If you aren't scared of warping, you can try a flushing tip on your torch. If you have an arc gouging gun, you could also scarf off the welds, that's quick and dirty.

Grant

You used to scarf those off with a big Gas Axe with a curved tip, so the cutting oxygen jet was parallel to the surface. Hit the Oxygen lever, and the offending material starts to disappear at a rapid rate, and rather neatly if you had the technique down.

I watched a Maestro clean up the old weld from the baseplate of a light post, and then we chopped off the bottom three inches of the post where it rusted out and welded it back together again. (I putz around, but when it's structural work I let someone who welds all day and has the certs to prove it do the work.) And lots of Zinc Rich Primer before painting.

Wonder if they make curved tips for plasma cutters...? (Miller says to use the "extended" or "gouge" tips.)

-->--

---- Posted via Pronews.com - Premium Corporate Usenet News Provider ----

Thanks! I tried the sawzall. It works, but takes a while. And it eats up the blades pretty fast. The pipe is about 3/16 wall thickness.

I don't have enough experience with a torch to not burn through the pipe I'm trying to save. :-/

Consider this your training session. :)

--Winston

Are you using Milwaukee blades? :-)

Not sure how that metallurgical mix would react to mechanical cutting. Were it me, I'd just take a cutting torch to it. Realize you will probably have some blowback from scale on the inside of the wall, and cut it at an angle rather than 90 deg. to the pipe. At an axis parallel to a line drawn through the center. That way, you will just bounce off the scale, and actually get a prettier cut. Watch out for the drops. That stuff is heavy. I used to work on oil rigs.

Steve

----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----

---= - Total Privacy via Encryption =---

Now that I look, yes! In fact, they are labeled "The Torch" :-) It's not a Milwaukee saw, though.

I'd be interested in any tricks to keep the blade from overheating (other than "wait";) that seems to be what does them in.

That would be some kind of coolant. I recently discovered a spray can product made by Union Butterfield which works great and is very portable. It's basically a drilling fluid but it would work fine for keeping a sawzall blade cool too.

I think you should try cutting this with a torch. You might nick the parent pipe a little, but you will rapidly learn and gain confidence. It should be an order of magnitude faster than a sawzall.

Grant

Yeah, that chain pipe cutter will pop the post off the top rail real fast and leave a nice square clean cut - but that still leaves the "fishmouth" of the vertical post welded to the top rail pipe.

He's trying to cut that fishmouth and weld off, and either a plasma cutter or oxy-acetylene cutting torch is the tool for the job. The choice depends on what you have available or the budget for.

Angle grinder for cleanup, and a stick, wirefeed or MIG welding torch to fill in the inevitable divots. Then hit it again with the grinder.

-->--

Graduate school is learning to cut one exhaust pipe from the inside of a larger one that its a press fit into, and has been clamped for years.

Man, that's a lifesaver now and then!

Dave

If you don't have the torch and you do have the sawzall, a decent inverter and your pickup or car will work out fine. I've had best results with cutting steel with sawzalls if I drip a bit of oil into the cut. My brother the electrican put a 2KW inverter in his service truck to avoid having to bring his 5kw generator out to the job site. Uncle has a

I'm a wimp, only have a 300 watt in my car connected by cigaratte lighter socket to run camera, laptop, and battery chargers on trips. Figure out what your saw needs and double it for startup as a minimum

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

I thought this hater of fine oil pipe had cut the top into lots of short length pipe. Leaving the T on the post.

Best way is to put it into a long lathe and turn it down. :-)

Martin

Mart> >

----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----

---= - Total Privacy via Encryption =---

My gut reaction is that this will not work in a lathe. I think it will only work if this is a very stiff pipe (think short pipe) and you turn it down very slowly to avoid the tool jamming against the protrusion.

Best wishes,

Chris

What's that Lassie? You say that Sparks fell down the old rec.crafts.metalworking mine and will die if we don't mount a rescue by Sat, 09 Aug 2008 02:13:24 GMT:

What kind of blades did you use. I have been cutting up some scrap channel and tube, and have found that the milwaukee blades called " the torch" are way better than the "metal cutting" blades.

Congratulations, Chris! You figured out 'interrupted cuts'.

-->--