cannot get a neutral flame on my Oxy/acetylene

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I bought a brand new O/A kit last year. The small one from Praxair MC size acetylene. Victor torch. I an working with small round steel stock 1/8 to 1/4 inch for weld sculpture. I'm a rookie as I havn't used o/a since high school and I am now 64. Despite my best effort I could not get a fuse weld happening as I would just burn thru and the rod would fall off.After burning thru several tanks of O/A I gave up in frustration as I thought I'm just an idiot. Well two weeks ago after much internet research I thought dam it I'm going to get this but I still cannot get the neutral flame I see in all the demos viewed. I then began to suspect the torch as maybe having a problem in the mix chamber. I drove an hour to the nearest big city with a torch repair service and the chap there put my torch on his system and immediately pulled a neutral flame. He asked me what settings I was using on the O & A, I told him the suppliers recommendation of 5 & 5 psi. He said not enough on the Oxy. He then demonstrated how the Oxy pressure must push thru the footvalve before the backflash arrestor, then thru the backflash arrestor itself. He advised me to turn my Ox up to 20 psi and see if that helped. I told him I had tried various pressure's on both but Oxy only to 15 psi. He then suggested there might be something wrong with one of the regulators.I went home and set the oxy to 20, acetylene 8, no change. Oxy 25/ acet 8, no change. By no change I mean the cone is blue white and pointed, the lead flame is orangish/yellow red. This is no matter where I set the O/A. All I do is cut off rod before I can puddle. The weld if I do get one is brittle and falls apart with the slightest pressure.It's not rocket science. I have followed the instructions carefully on how to purge, light and adjust the flame to no avail. At low pressures i.e. 5 and 5, could it be the oxy regulator is not sensitive enough? Any thoughts out there!
Reply:Did you try the 20 psi oxy at the 4psi accet. 8 psi seems too high for that size material. What number tip are you using? If he got a good flame I would suspect the regulator. Not sure who makes praxairs torches I bought smith torches and regs cause I got tired of probs with cheap torches and reg probs.Millermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:I suspect that your real problem may not be a failure to get a neutral flame, rather you do not have a big enough tip to weld 1/8 inch thick material.   You did not say which tip size you are using.  If you don't have a big enough tip, all you will do is melt the welding rod, you will never get fusion on the base material.You can get a bigger tip or try thinner material.Getting a neutral flame is easy, to my way of thinking, you turn up the acetylene until you get the long cone, and then turn it down until the long cone merges with the short cone.   A neutral flame and an oxidizing flame look a lot alike to me, but the carburizing flame is very different.As always, if you can get a welding friend to look at your setup, they may be able to figure out the problem in 5 minutes or less.RichardSculptures in copper and other metalshttp://www.fergusonsculpture.comSyncrowave 200 Millermatic 211Readywelder spoolgunHypertherm 600 plasma cutterThermal Arc GMS300 Victor OA torchHomemade Blacksmith propane forge
Reply:No matter how I try to figure this, it still makes no sense to me.You know for cetain that your welding torch is OK - having that fellow check it out.I wonder if you are following the correct procedure to attain a neutral flame?In my case.0 - Make certain both valves on the torch are fully closed.1- open the acetylene tank valve, then2 - open the acetylene valve on the torch,3 - adjust the acetylene regulator, screwing the fully backed off T inwards until I have 5 psi.4 - shut off the acetylene valve on the torch5- open the oxygen tank valve, then6 - open the oxygen valve on the torch,7 - adjust the oxygen regulator, screwing the fully backed off T inwards until I have 20 psi.8 - shut off the oxygen valve on the torch9 - slightly open the acetylene valve on the torch and light the torch10 - adjust the acetylene valve on the torch until I have a bushy yellow flame11 - slowing open the oxygen valve on the torch and watch as the flame goes from sooty yellow, to yellow, to white, then watch the three cones of flame one within the other and continue to add oxygen until the inner two cones just merge = neutral flame,For welding steel, I bring the tip of the merged cones almost into contact with the surface to be welded.  Once I form a weld puddle, then I will add in filler to the weld pool and motor along.Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:Originally Posted by lexus3548....I would just burn thru and the rod would fall off.....
Reply:look on a site called tinmantech..they describe amethoid for setting up a welding torch that does not rely ongauges, which can be misleading. i used to weld with a 20' set of hoses. i added 25' so i could weld in a different location and the gauge settings are way higher now to overcome the hose resistance,,and what was said about gas velocity is very impportant..choose a larger tip and run it at lower p[ressures or you'll blow metal all over..look for an article called    zen and the weld puddle which describes very well what a good weld puddle looks like..
Reply:Get a flame lit and take a picture (as clear as possible) and post it.Miller thunderbolt 250Decastar 135ERecovering tool-o-holic ESAB OAI have been interested or involved in Electrical, Fire Alarm, Auto, Marine, Welding, Electronics ETC to name a just a few. So YES you can own too many tools.
Reply:You said you couldn't get a neutral flame, but the guy at the repair service could . . . so the torch is probably okay.You also stated that you've been through several bottles of oxygen and acetylene ruling out a bad bottle of gas.  However, you've been through several, so I'm guessing they're small.  If you're using an MC size acetylene, the tank is too small and you could be drawing acetone into the torch.  To weld 1/8 inch steel you need a tip at least .043 inch diameter.  That will use 6-9 CFH of gas.  Since the MC bottle is only 10 cu. ft., you've violated the 1/7 rule several times over.   Use a smaller tip and see if you can get a neutral flame.  BTW, I highly recommend the Tinman method of adjusting the regulators.JimDynasty 300DXSmith He/Ar gas mixerMM350PHobart Handler 120Smith LW7, MW5, AW1A
Reply:I use a size 1 Victor tip to weld 1/8" frequently with both O & A at 3-5 psi.  20psi for oxy sounds like what I use for cutting tips.Hobart LX235Victor 250 Oxy-Acetylene Rig (welding and cutting)Bobcat 773F-350, 1999, 4x4, 16' 10K# trailerOutdoor Wood Burner - 10 cords/year
Reply:Disconnect the hose at the reg and run some gas through each reg (crack the cylinder valve) to see if you have good flow. If you do not then pull the suspect reg, crack the cylinder valve to see if there is good flow there, then check the sintered SS filter at the inlet, could be plugged with debris. If you have good flow, then install the next piece in line (check valve?) and check again. Then install the hose and check again. You likely have a plugged filter, a check valve/flash back arrestor installed backwards, or a kinked hose. The other possibility that I have run into with cheap hose is that the inner liner gets blistered/bubbled and swells to block the hose. Use only US made hoses to avoid this. This is just a process of elimination, start at the beginning, go through each piece until you find the one that is restricting your flow.