cutting with propane / oxygen

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I am totally new to cutting, my son has had several classes in school and knows more than I-except he hasnt done any cutting with propane/oxy...we are about to start a project which requires cutting many (35) cow stanchens out of our barn and some old water pipe... the stanchen are about 21/4 water pipe with solid 13/4 - 2 inch rod for strength inserted into them where we are cutting them at concrete floor.. we have a victor torch head... what size tip should we use and at what pressure settings.. I have tried to find this info for the past hr and half looking thru previous posts but cannot find the answers...any help would be appreciated...
Reply:I would go rent a cutoff saw if you have a lot of them,
Reply:i would think the gap between the pipe and rod is going to give you quite a bit of grief with a torch.XMT 350 MPa, w/D52-DTA 185 TSWHarris of
Reply:Originally Posted by sjamesi would think the gap between the pipe and rod is going to give you quite a bit of grief with a torch.
Reply:watch out for the concrete popping when cutting close to the floor. That stuff will do damage and it does hurt having hot sharp concrete chips blasting you at random intervals. I still recommend a cutoff saw. 1-2 blades and tank or two of fuel to do the whole job, It will be louder but either one will make a lot of sparks and smoke. The saw will probably require less screwing around to make it work and the whole thing can be cut off in one shot and move onto the next one
Reply:Originally Posted by ironmangq.....I still recommend a cutoff saw....
Reply:I'd just do it all with a #2 for the sake of speed. It's good torch cutting practice so play a bit and learn the differences. I hold LP tips a bit further out than acetlylene. You'll get faster as you go.Cut pipe, sling it out of the way, cut rod. First few will be slow as you figure it out.Wear a tinted FACE SHIELD (they are MUCH more comfortable than goggles and breathe better) and safety glasses (because stuff bounces). Have a water hose handy.  I wear a leather jacket when cutting nasties so whatever wants to bounce off is welcome to do so.A cutoff saw would work, but torch cutting practice on expendable metal is a good idea so you'll be ready for torch work where cutoff saws won't go.
Reply:Myself, I'd probably trade gas consumption for fast clean cuts. That way, I believe the posts could be nipped in just seconds each.So, I would probably gear up with a 90 degree torch fitted with about a 4" - 6" capacity  tip, probably with settings of 15psi fuel and at least 50psi oxygen. Adjust flame for a heavy pre-heat. For technique, I'd rest the torch head on the floor with the handle positioned vertical and up. I'd start by preheating the outer tube with the flame's edge, and as soon as the tube starts to "burn" roll the torch so that the burning tube is directed to furthers the cut by igniting the inner solid. I'd continue the cut with one continuous roll and no other torch movement.  After the post drops and while everything is still hot, if necessary, take another slice to leave the stub flush.Follow the usual precautions and beware of popping concrete.Good LuckLast edited by denrep; 05-10-2011 at 06:34 PM.
Reply:I cut about 50 stanchions out of a barn. Cut outter pipe than insert. Use a hammer to knock rost off before cutting.  I have also used a 9" grinder with a slicer wheel to cut off flush. It works just watchout if it bind up.Millermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:Just to be clear you are using the two piece propane tips and Grade T hose right?  Make sure your torch handle has flashback protection.  Did you get an LP gauge or are you trying to use an acetylene gauge?
Reply:Thank you for all the replies..some of you make it sound so simple-routine, then again im a cabinetmaker by trade... I have a #2 propane tip (victor) and the torch has flashback protection... using regular oxy/ace hose and gauges...I would rather not use a cutoff wheel and definetly need some experience learning the torches... the cuts dont need to be perfectly flush as i intend on knocking out the concrete ledges so eventually i can have a large work area. i can order a #3 tip if thats better suited. wish there was a class or something to learn this stuff, seems like my 47yr old brain dont learn the same.. probably not the age as much as what i put it thru. thanks again guys.
Reply:Number 2 is big enough just a little slower. Nothing like a little practice or about 30 times. Just watch for popping cement that hurts. Sometimes it works to cut partwaythrough than brak off with a maul depending how old or crappy the pipes are. They arent plastic sleeved are they thats antoher pain in the rear.Millermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:yep-they are sleeved.
Reply:good sharp chisel or else a grinder to slice them off sometimes the soild rod will just pull out after you cut the outter pipe.Millermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:Originally Posted by 85cj7boyJust to be clear you are using the two piece propane tips and Grade T hose right?  Make sure your torch handle has flashback protection.  Did you get an LP gauge or are you trying to use an acetylene gauge?
Reply:So what would be the proper pressure settings to start at with a #2 tip vs a #3 tip...and adjust up to ?? to improve the cut....not real concerned about conserving gas-just want to get it done - and safely!
Reply:I run about 7-8/25-30 psi. Just play with it a bit, since the pipe is scrap anyway. You'll be playing with the TORCH valves much more, and figuring out how much tip standoff from the workpiece to use.You could park at the first post and make multiple cuts to get your setting right. Think "training"! Cutting is an acquired "feel". You'll do fine.Denrep had a good idea about going up to a larger tip since it's a scrapping job, but practice with ALL your tips because what you LEARN is valuable!