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Gas welding Aluminium.

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  • Bill Tromblay
    replied
    Hi,

    I went back to page one of this post and say your low pressure gauge set up, that will work fine, I forgot you did that. I found a company that rebuilds and sells regulators and very good pricing. Once I talked with him, he set me up with duel stage regs, with low tension springs and low PSI gauges. Now the flame is very stable and controllable. I can send his contact info if interested.

    B

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  • cliffrod
    replied
    Originally posted by Bill Tromblay View Post
    Hi Cliff,
    Yes, oxide has a higher surface tension than non-oxidized aluminum, this is due to a higher melt temperature of aluminum oxide, then the base material. Flux is chemically cleaning the surface of oxide and de-gassing the weld pool. Because of the oxide issue, it is always good to wire brush or scotch brite the weld area before you start on both side, in both gas and tig welding.

    If you search McMaster/Carr, they sell 0-15 psi oxygen approved gauges that you could use to replace your 0-150 psi units. Only use Oxygen approved gauges on the oxygen side due to a danger of mixing oil in a O2 system. If you go the low gauge route, every day when you are done welding, be sure to back the regulators off, to eliminate a surge when you open the tank the next time and damage the new gauges. Good practice with any regulator.

    I can bring the hydrogen to Jim Hury's event, if you are interested in giving it a try.

    Hope it helps and you are doing well.

    Bill
    Is the regulator for low psi different (thread pitch or rate of actuation) than a regular regulator? I thought I needed more than just a gauge, so had put off the expense getting another regulator & gauge. When I found I could use this external pressure gauge for free, I was quite happy. I always fully release my regulators when I close the tanks at the end of any welding.

    i would like to try the hydrogen. Thank you for the offer.

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  • Peter Tommasini
    replied
    It's good to see you guys sharing tips and tricks on all subjects regarding metalshaping ...keep it up
    Peter T.

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  • cliffrod
    replied
    Thanks, Bill. I figured the function of flux would mean a difference in surface tension. No worries, I'll keep practicing.

    I hope all is well in your world. Things are good here. This sculpture business has been much like covid days for at least a decade, so not much different. I talked to Jim yesterday. All is good there, too. He's still planning on the RR in Aug as long as covid things are ok. But he got so much happening it sounds like we might have to have the meet next door. Not sure there'll be any room left in his place for visitors.....

    Leave a comment:


  • Bill Tromblay
    replied
    Hi Cliff,
    Yes, oxide has a higher surface tension than non-oxidized aluminum, this is due to a higher melt temperature of aluminum oxide, then the base material. Flux is chemically cleaning the surface of oxide and de-gassing the weld pool. Because of the oxide issue, it is always good to wire brush or scotch brite the weld area before you start on both side, in both gas and tig welding.

    If you search McMaster/Carr, they sell 0-15 psi oxygen approved gauges that you could use to replace your 0-150 psi units. Only use Oxygen approved gauges on the oxygen side due to a danger of mixing oil in a O2 system. If you go the low gauge route, every day when you are done welding, be sure to back the regulators off, to eliminate a surge when you open the tank the next time and damage the new gauges. Good practice with any regulator.

    I can bring the hydrogen to Jim Hury's event, if you are interested in giving it a try.

    Hope it helps and you are doing well.

    Bill

    Leave a comment:


  • cliffrod
    replied
    Great information, Bill. My gas welding needs lots of practice and no oxy-hyd plans here now, but this helps a lot. I've got a question you or someone else may be able to answer.

    With oxy-act I haven't found I'm producing salt/crystalline inclusions. The gauges allowed me some manner of consistency because my regulator gauge is a 150psi as mentioned so it doesn't budge at nominal pressure settings. I was frustrated about inconsistent results and crappy welds as posted previously.

    Resolving a properly numbered but damaged/deformed #3 tip has helped a lot. Not much welding time since then, but running a quick bead along a coupon of aluminum with this tip allowed me to produce a fully liquid pool with great control, either consistently flush with the surface or pendant/sagged without any loss or holes even along an edge. It was like I was welding much thicker material than before, lots more control. I didn't use flux for this quick test, so there's a layer of oxide over the bead portion.

    before I assume that I've improved and then just produce more scrap- Does a skin of oxide on an unfluxed molten bead have a greater/different surface tension than a fluxed molten bead?

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  • Bill Tromblay
    replied
    Hi,

    With the hydrogen unknowingly at 10 psi, I was running the oxygen (unknowingly) at the same pressure. The Oxygen needed to be that high, to create a cone. So even with high pressure, you can mix the gas to change the cone length, just as you can at 1 psi. The one thing i noticed with the higher pressure, you could go from a cold flame, to brutally hot, with a slight bump of the control valves on the torch. You had no fidelity with the controls. With the pressure now set correctly, I have a lot of control. One way I thought of explaining it, would be to turn up the TIG welder to full amperage than weld with it. Can you do it? Sure, but it isn't easy and will look bad.

    I saw a picture today on-line of a Oxy/Acetylene gas weld on .063" 3003 aluminum and they had it set at 4 psi Oxygen and 4 psi Acetylene and their results had the same appearance as my welds. You can see the "salt crystal grains" appearance running thru the top of the weld and the bottom looks fine. As metal shaper's, most guys dont care about the appearance, because you grind the weld off or planish it into the surface. On most aircraft components, the welds were left visible, and caused my concern to solve the problem.

    B
    Last edited by Bill Tromblay; 04-22-2020, 11:06 PM.

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  • joeswamp
    replied
    Hey Bill -- Are you saying that you were oxidizing the weld because your oxygen was set too high, or are you saying that both pressures were set too high? If it's the latter (and you were putting too much heat into the weld), doesn't that mean the length of the innermost cone would have been too long? I thought that the little inner cone length was really the critical factor, as it correlates well with gas flow. This is assuming the flame is close to neutral.

    Maybe these are dumb questions as I've never tried oxy-hydrogen welding, I've heard you can't really see the flame and so I have no idea how you would adjust it. The flame is cooler so I'd expect you could go a little slower than with oxy-acetylene. I do know that a lot of people prefer it.

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  • Bill Tromblay
    replied
    Hi,

    I was thinking and this may be a possibility. The cheek method may work with oxy/Acetylene, even though the welding books recommend the same low pressures. But I do know that does not work with Oxy / Hydrogen. I haven't come up with a reason as to "why" one and not the other, just my experience. Kent knows what he is doing and what he is talking about and I know the cheek method works for him with acetylene.

    B

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  • Chazza
    commented on 's reply
    Great advice Bill!

    So the puff on the cheek did not work for you?

    I have tried the cheek method and the normal regulators, but not the method Cliffy uses,

    Cheers Charlie

  • Bill Tromblay
    replied
    Hi,

    I have the Henrob, and it is ok. The aluminum handles make it heavy and the pistol grip works great for a pistol, but not so much for welding. I use mine for Oxy/Acetylene welding and it works fine, but I prefer the Meco Midget.

    Setting of pressures to your cheek and my year and half learning curve.... 😩 Short back story on my knowledge. I received certification for Aerospace welding with the use of Tig, steel and aluminum. I think I weld relatively Ok. Others can weld nicer, but I get the job done that is Airworthy. I think I understand the concept of gluing two pieces of material together with a weld. So, I decided to learn something new and go the Oxy/Hydrogen gas welding route as used by the aircraft company's of WW2. I bought the all the stuff new, gauges, hoses, Meco Torch, flux and on and on. I ordered the videos and every book I could find on the subject and sat down with a bowl of pop corn and watched away. "The trick" you don't need to use the gauges, turn up the regulators until you feel it on your cheek and go as described above. Great, off to the races.... The reg's that I bought had 0-150psi gauges installed, as you turn up the pressure and feel it on my cheek, it wouldn't move the needle off the peg, (but that is ok, because I have this trick).

    Unknown to me at the time. When I would weld, a scab of aluminum would form over the weld (like you see on a casserole or on brown gravy) and the heat was extremely hot ( i'm going down in tip sizes from the recommended sizes). I would weld so fast, I had to use 1/8" dia rod, because I couldn't feed fast enough. The weld bead would look beautiful on the bottom, but the top would look like grains of salt,, stuck in the weld. No matter what I did, I couldn't make it go away. Leak checks, filters, different operator, different gas, same result. I consulted with above and others... The issue was "me" or "bad technique" or "what do you expect" or "fix your equipment (even though it was bought new from a guy in California)". But I didn't give up and I tried and tried and tried, varied my techniques, and equipment and no matter what I did, I would get the exact same result. One thing was for sure, no matter what I did or varied, I would get the exact same result (guess I had more skill than I thought).

    Then..... One Saturday morning I log into Facebook and a guy by the name of Solice metal works is Oxy/Hydrogen gas welding some aluminum fenders together with the most beautiful work and beads you can imagine. I quick welded a test bead, still crap... Take a picture send it to him in a message and wait for a response. He writes back 5 min later with one question "what pressure are you running at??" Hmmm...??? I removed the 0-150psi gauge and installed a 0-15psi gauge that I had laying around. Opened the regulators and the torch and looked at the pressure. Alcoa, Reynolds Aluminum, Kent Whites booklets and videos, WW2 welding manuals all state that Oxy/Hydrogen welding should be set at 2psi Oxygen, 1psi Hydrogen. My highly calibrated cheek is set at 10 psi.... After wetting my pants, I turned down the both regulators to 2psi and 1psi respectively and proceeded to weld the most perfect, beautiful, wonderful, joyful weld that I have ever seen... Wetting my pants again on the process...

    The scab and crystallizing of the weld pool was caused by oxidizing the living F#^& out of the weld, because the pressures were so high. It took a year and a half to finally figure out the problem and was by far one of the hardest things I ever learned. I have since bought overhauled two stage regulators with low tension diaphragm springs and low pressure gauges. The repair shop specially set them up for low pressure work.

    Tricks and short cuts are great, but only once you learn the fundamentals. Every one says you have to move when you gas weld or you will blow holes, not true with the right equipment. I can gas weld .025" thick 3003 with no holes. Holes can still happen, but nothing like you see in the training videos that are out there.

    Hope it helps someone save the time I invested, by some not so go advice.

    Bill
    Last edited by Bill Tromblay; 04-18-2020, 08:35 PM.

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  • Chazza
    commented on 's reply
    Thanks Cliffy. What a good idea!

  • Moving molecules .
    replied
    Does any one like the Henrob or Cobra... it’s a funny looking thing ...but Does it work.
    All very Expensive for me to buy from the US.
    need to buy something for are new company... so need some ideas.
    Used a old school torch in my old place sadly NLA.
    Last edited by Moving molecules .; 03-17-2020, 01:52 PM.

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  • cliffrod
    replied
    Originally posted by Chris_Hamilton View Post
    Setting up the torch correctly doesn't even require you looking at the gauges. If you have Kent's video Gas Welding Aluminum "The Difficult" Part 1, he shows the proper way to set it up. Same way Peter did at the class I attended.

    Open your tanks, back off both regulators completely, open your torch all the way, both the oxy and the acetylene. Hold the torch next to your cheek, gradually open the acetylen regulator until you feel a puff against your cheek. Light the torch (not against your cheek) Continue upping the pressure of the acetylene regulator till it burns clean. Gradually start adding oxygen with your regulator. Add more acetylene, then more oxygen until you don't see anymore increase. Now gradually run in your valves on the torch down to the size of the flame you want. Done.
    No videos or DVDs here. No matter, I'm 99.9% certain Kent is the one who suggested (over on AMS) using a pressure gauge like this. so I hung a spare one on my cart and do it that way.

    Really can't remember if Peter suggested the cheek method when I took his class. It was more about wheeling.

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  • sparky
    replied
    Originally posted by Chris_Hamilton View Post
    Setting up the torch correctly doesn't even require you looking at the gauges. If you have Kent's video Gas Welding Aluminum "The Difficult" Part 1, he shows the proper way to set it up. Same way Peter did at the class I attended.

    Open your tanks, back off both regulators completely, open your torch all the way, both the oxy and the acetylene. Hold the torch next to your cheek, gradually open the acetylen regulator until you feel a puff against your cheek. Light the torch (not against your cheek) Continue upping the pressure of the acetylene regulator till it burns clean. Gradually start adding oxygen with your regulator. Add more acetylene, then more oxygen until you don't see anymore increase. Now gradually run in your valves on the torch down to the size of the flame you want. Done.
    Ha Ha... You wont find this this little tip in the safety manuals.😋

    Leave a comment:

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