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Welding 2025

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  • Welding 2025

    I’ll start with the questions first and then the random thoughts.
    When setting up to do oxyacetylene welding:
    What size cylinders are other builders using?
    What length of hose are you using?
    Do you raise the outlet pressure to compensate for pressure drop?

    The reason I ask is because my shop is small, it would be most convenient to mount the cylinders to the shop wall and use 25 ft. hoses. This would enable me to reach everything in the project, including outdoors in front of the shop where I will start practice work and small part fabrication.

    Alternatively, I could use the 10 ft. lightweight hose and a cylinder cart if it really is best to be right next to the regulators, and if standard hose is too ungainly and pressure drop is unacceptable in the longer hose.

    The equipment I have so far is the Miller Smith Airline AW1A torch and tips and a rudimentary welding table. Since I will have to wrangle the cylinders myself into and out of the car, they can’t be too heavy. On an EAA forum thread, somebody said 80 cu. ft. of oxygen is enough to weld more than one fuselage. Can that be true?

    I imagine Bob still includes the photo demonstrating OA is good and TIG is bad in his booklet with the plans. But seems lately the debate over OA versus TIG has settled down a bit, both sides agreeing either method is acceptable when done properly. I’ve decided to pursue gas welding and am persuaded it is the easiest method for the beginner to start with. TIG will be an option if it seems necessary.

    My go-to guide is the EAA, of course, with gurus Earl Luce and Budd Davisson leading the way. I have a book and DVD and have bookmarked many EAA webinars, tips for homebuilders, articles, and forum discussions. With the passing of Kent White, tinmantech.com no longer seems to be available.

    There have been some good threads here on the forum also.

    Locally, I continue to search for instruction. The community colleges and trade schools all want students to enroll in certificate programs. So far I have not found auditing to be an option. The college of Youtube of course has a lot of valuable information. General Air Service and Supply offers one-day courses in various welding methods. Hopefully in May there will be an OA course available. Talking with the guys at General Air about regulators and cylinders and such, they view OA as something you use strictly for cutting, and insist that what I am talking about is brazing.

    My best bet is my EAA chapter where there are one or two old hands who may be of assistance. I attended a TIG workshop a while back conducted by one of our senior leaders. He’s also a Tech Counselor and presumably knows plenty about OA as well. Soon, when I have the basic setup assembled, I will make a public appeal to my chapter for assistance. I’d gladly pay for some one on one tutoring just to get me started on practice work safely and without bad habits.
    Last edited by Frank; 04-25-2025, 11:02 AM.
    Frank Forney
    Englewood CO
    https://eaabuilderslog.org?s=FranksLSA
    EAA Chapter 301

  • #2
    I just use the small HVAC Port-a-torch size bottles. I did buy one extra oxygen and two extra acetylene bottles. Sometimes I wish I had larger cylinders just to I don't run out of gas mid task, but I've gotten by. I have a Meco midget torch with lightweight hoses and really like them, so much easier to hold and manipulate in tight spaces.

    Comment


    • Frank
      Frank commented
      Editing a comment
      Judging from the photos you have posted, you scratch built a fine fuselage! I can imagine using a small welding setup like yours could be very easy to handle in and around the project.

  • #3
    Learned from Earl years ago.

    My oxygen cyl including the valve is 47 inches If I had to guess they call it a S, maybe 125 cubic feet (not including protective valve cover )

    My Actylene cyl including the valve is 38 inches I think it is 145 cubic feet


    same A1wa torch as earl used.



    I have never found the length of the hose to matter.
    I even connect a A size(3/8) kevlar hose to the regular B(9/16) size hose

    k.jpg


    Make sure and get back flow flame arrestors
    f.jpg


    You will find when you go to get a cylinder they will be brand new when you get them.

    Then on the first refill those cylinders are gone and you will have something much older.

    I think the industry says that you are only leasing them for a 100 years. I think all welding supply shops operate the same way. They have no choice. There is no way they can
    fill a tank when your pull up and keep track of which cylinder is yours.



    No matter what you do the oxygen and acetylene run out at different times, and you are not going to see those new cylinders again.



    You have to be a bit careful if you buy cylinders from some place other then the welding gas supply store as they may not want
    to take your cylinders in trade


    You might even find that they do not have them in stock.




    Last edited by sjt; 04-26-2025, 02:50 PM.
    Stan
    Austin Tx

    Comment


    • Frank
      Frank commented
      Editing a comment
      Thanks Stan. My supplier sells small tanks and leases the larger tanks. The O2 tank you describe leases for three years at $300. Other people are confirming that hose length is not a factor. But I still wonder what outlet pressure people are using. Is it 5 psi regardless of hose length? The 10 ft lightweight hose is pretty pricey.

    • sjt
      sjt commented
      Editing a comment
      If it is 5 psi at one side of the hose it is 5 psi at the torch.


      The flow rate is not that high.
      The welding tip orifice is pretty small. acetylene is pretty hot.




      From my experience:
      As a rule the correct size tip is the one that will bring your 4130 to welding temp in 3 seconds.

      If it takes 5 seconds use a bigger tip.

    • jaredyates
      jaredyates commented
      Editing a comment
      I just set the regulator flow based on how things are going at the torch. If I'm full open on the torch valve and not getting enough fire, I tighten the regulator knob a little. If I barely crack the torch knob and am getting too much flow, I back off of the regulator. If the regulator did not have a low pressure gauge it would be fine.

  • #4
    I have a Smith AW1A, light weight hoses connected to a 25' hose. I took a chance and bought 2 empty cylinders off Craigs list. Took them to the welding supply and they exchanged them for full ones, no questions asked. Now I'm golden, I exchange them when empty. I got big ones, oxygen is a K, acetylene is a KW. The whole rig on a cart takes up a lot of space though. Good luck.
    Gerry
    Patrol #30

    Comment


    • Frank
      Frank commented
      Editing a comment
      Is that 25 ft hose a standard hose with B fittings and A adapters at the torch? Do you find the hose to be heavy and a problem? Or did you just get used to it?

    • geraldmorrissey
      geraldmorrissey commented
      Editing a comment
      My 25' hose is standard. And somewhat heavy. The lightweight Kevlar hoses shown in Stan's post are a joy. The lightweight hose look fragile though, I treat it with great respect. Because my cylinders are on wheels, I can get close to the work and often only need to unwind the Kevlar hoses.

  • #5
    Check around at different welding supply stores?????

    $300 should be a lifetime purchase for an S cylinder 125 cubic feet.
    (Like I say it will be traded in for an old cylinder on your refill)

    Maybe it is different in your part of the country???


    Also, that is for an empty cylinder you will have to pay for the oxygen. I have not done it lately but the oxygen will be $75 to $100.




    e.jpg
    I bought above from home depot. It goes for $345 these days

    NorthernTools sells something similiar for $245 but it does not have a rosebud or all of the tips.


    I think the hose is 15 feet. You would have to check but the above equipment uses the 9/16 b fitting

    Sooner or later you will want a rosebud and cutting torch.

    Maybe not on your airplane, but if you have a torch you will find something







    For my airplane I use a smith AW1A. I know you will need the aw201,aw203 tips
    I also use an "A" size (3/8) kevlar hose which is spliced onto the homedepot "B" size

    b.jpg f.jpg Forney 86152 Oxygen Acetylene Brass Fitting, Oxygen and Acetylene Hose Couplers, Adapters A to B Oxygen and Acetylene, Carded Pair


    The a to b fittings can be found on Amazon for under $16


    I do this just because the AW1A is small and light weight .
    Most importantly I do it this way because I am building an airplane to generate reasons to buy every tool I can think of.


    I have seen these for as low as $162 (weldingstore.com)
    a.jpg
    You need at least two different tip sizes
    They go for something like $60 apiece
    If you go with this style torch get the aw201 and aw203



    aa.jpg
    Last edited by sjt; 04-26-2025, 02:51 PM.
    Stan
    Austin Tx

    Comment


    • #6
      As you can see there are a lot of local variables. I have a set that is about 3-4 feet tall and then have a small portable set. For some reason I only run out of welding gas at 5:05pm on a Friday and having the two tanks gives a backup. Those little tanks have also come in handy for portability. The Airgas where I live is very flexible with core tanks. I take in some/any empty tank and they send me out with whatever I am after. I buy empty use tanks for around $50 and figure if Airgas ever changes their mind, I'll make some gongs for the shooting range.

      Comment


      • Frank
        Frank commented
        Editing a comment
        Those cylinders make nice gongs. Yard sculpture and lawn ornaments are my backup plan if the airplane project fall through.
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