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  • Newbie... First post

    Hey everyone.
    I'm starting my oxy-Acetylene welding journey and lit my torch for the first time last night.
    I picked up a used set of cylinders, Victor torch, regs, hose, etc. from a neighbor and my goal is to be a good gas welder by the time summer is over.
    I'm going to be primarily working on mild steel tubing in diameters ranging from .75" to 1.5". Welding is my primary focus, but also brazing and soldering too.
    All that to say...
    I own Richard Finch's book on welding as well as Steve Bleile's DVD on gas welding. I set up the regulators according to their recommendations at 4 psi (for my #2 tip valve opened up 1/2 turn) opened up the Acetylene, hit the striker, opened it up a little to lessen the smoke, then started opening up the oxygen. I was able to adjust my flame to neutral and everywhere in between. I got a good feel for the adjustment range.
    I was under the impression that a good, neutral flame would be pretty quiet, but when I was adjusting my torch, it seemed fairly loud and "hissy". I could turn the torch valves down and make it quieter, but I got to the point where my acetylene regulator started "flipping". That's the best way I could describe it. I think the regulator was "turning off and on" quickly due to my torch valve being so low. I wasn't looking at the pressure on the gauge when the torch valve was low, but I suspect it was much lower than the 4 psi I started off with the torch valve opened a 1/2 turn...
    I could increase my regulator pressure, but that seems like it would be a waste. Opening the torch valve would achieve the same thing yes?
    I guess I just thought it would be quieter. Not a big deal, but that's my "newbie-ness" showing.
    Please, if you see anything glaringly wrong please correct me. I've got some .125 thick mild steel to start making puddles on. That'll probably start soon!
    Thanks all!
    Dan

  • #2
    I haven't gas welded for awhile, but the last thing I did (broken chaise lounge) is in my backyard and has survived teenagers. The oxygen intensifies the acetylene flame and I remember it hissing a little. I think when you get it quiet either your mixture is off and I'm remembering that a soft flame is slightly fuel rich and carbonizing or you're too low on pressure for the tip size and risk a pop or flashback. I'm sure somebody with more experience will be along soon.

    However, let me say I'm glad you're starting with some practice pieces and not trying to weld spring hangers on your truck or whatever today. Too many people go for the money shot 15 minutes after opening the package. I don't weld alot and still burn a rod or two on scrap to get my feel back before I weld anything important.
    Blacksmith
    Stickmate LX AC/DC
    Big cheap (Chinese) Anvil
    Hand cranked coal forge
    Freon bottle propane forge
    HH 210 and bottle of C25

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    • #3
      There's a great little video on the EAA website (Experimental Aircraft Assoc.) that shows how to adjust for the perfect "neutral flame". I've seen pictures in books, but never one as good as this small video. So, I was able to make the 3 cone carburizing flame, and an oxygen-rich, oxidizing flame (which was pretty loud) and everything in between. I just noticed that the valves on the torch body had a large range of adjustment. I'm assuming that as long as my cylinder gauges are reading 3-4 psi at whatever torch valve opening I'm using at the time (regardless of how loud I think the torch is) I should be fine.

      One other thing is when I had the torch valves opened up a little more, there was a little distance between the torch tip and the flame. As I turned down both torch valves, that gap was eliminated. So, again I assume that there should be no gap between the torch and the flame. This is what I see in the videos anyway...

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      • #4
        Gas torch flame makes noise. The bigger torch tips makes more noise.
        When you adjust flame properly gas welding is safe because gas velocity coming out of torch orifice is higher than flame velocity can burn up stream into the torch tip. Back fire is a series of pops. Flashback a shrill hissing. Cold torch tip cools flame trying to burn past orifice. Welding into a corner of fillet weld heats torch tip more making backfires more likely to happen. When you adjust flame lower to weld thinner metal backfires and flashbacks are more likely to happen. Use correct sized torch tip for metal thickness turned up enough to prevent backfires and flashbacks.

        When you hear a series of backfires while welding pulling torch away from work should stop the pops. IF pops continue turn off O2 and Fuel valves and allow torch to cool before lighting again. Adjust that torch tip to bigger flame or when smaller flame is needed change to smaller torch tip.

        If you hear a shrill hissing of flashback turn off cylinder valves. Fuel valve should be open only 1/4 turn so it is quickest to turn off. Turn off O2 valve also. This should stop the fire. Your torch will need repair or replaced.

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        • #5
          I don't think my "pops" were due to a backfire. I think it was just because I was trying to dial down my torch valves down to be quieter, and as I did that, I was "choking" the regulator and it was kind of turning off and on quickly. The needle on the gauge was flipping up and down between 0 and 4 psi.
          So, I guess using a #2 tip will just have a hiss to it. I'll try my 0 and 00 and see how that loud those are.
          Thanks for the help!

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          • #6
            I melted some metal last night for the first time! I have pics, but they're still on the camera. I started with just pushing a puddle around my piece of steel. Got bored of that kinda quickly so I played with a little RG45. Weird at first, kinda like playing the drums... each limb does something different, but when done right it's a great beat. Keeping track of my torch distance, angle, movement, puddle, when to "dip", staying in a straight line, etc. was a little challenging, but really fun. Here are my take-aways from the first night:

            I'm not properly dressed. Torches are HOT. I was using a pair of "Mechanix" gloves instead of full leather, and I couldn't even weld past 6 inches because my hands got too hot. Ditto that for my short sleeve shirt. I did have a shop apron on however...

            I may have an issue with my acetylene regulator. before I lit the torch, I opened my Acetylene torch valve up 1/2 turn, opened the cylinder valve 3/4 turn, adjusted the reg to 4 psi. Closed torch Acetylene valve, opened it back up about 1/8 to 1/4 turn, lit it, increased to about 1/2 turn open (where the smoke was lessened) While opening the Acetylene torch valve, I experienced the "Popping" for about 5-8 pops then it magically settled in nicely. After that, I'd add the appropriate amount of Oxy to get my neutral flame. I'd make a puddle with that flame and I got lots of sparks from the puddle. I could turn down both torch valves and the flame would get quieter, and I'd have less sparks, but my reg was all over the place. With the torch valves open about 3/8 of a turn, the pressure was reading 6 psi... but just a minute ago I adjusted it to 4 psi at 1/2 turn... plus the popping thing... kinda makes me wonder about the reg.

            I know I'm not using the perfect items to test with. I bought some 1/8 inch thick steel at Lowes and cut it into 1.5x6 pieces. I also bought 1/16 inch RG45. I'm using a #2 Victor tip and I'm sure my 1/16 inch rod isn't perfect for that thickness of steel... But, it's what I have, and after I use that all up, I'll get some thinner material to practice on.

            So, to make this post even longer, I tried making a butt weld. I made 2 tacks on either end, then went for it. It was a pretty weld, but when I put it in the vice and hammered on it, I broke it pretty easily. Looking at the edge, I only penetrated about 1/3 into the 1/8" steel. So, I cooled it all off, wire brushed it, then tried it again making sure I got better penetration. The second time was much better. -Not as pretty, but I bent the steel below the weld when I tried to break it apart. I could see one place where I got 100% penetration so that was good, the rest was about 90-95%. So, for my 2nd weld of my life I was pleased.

            Lastly, when applying the torch to the steel, I was getting something odd. I was almost "burning" the steel and it was flaking off and getting into the weld pool. You know if you throw a sheet of paper into a fire and it burns right away, but there is a brittle, thin black corpse it leaves behind? It was like that on my steel. I could wire brush it away, but I don't remember seeing that on any of my videos or books. Again, wondering if my torch is adjusted properly.

            Thanks for hanging in there, please point out anything you see I could do better. I'll post pics over the weekend when I get them off my camera.

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