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Economical TIG practice on thin steel tubing with tube notching by hand

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    Economical TIG practice on thin steel tubing with tube notching by hand

    I am very short on funds, so I will be notching my tubes by hand for the next several months. While I will be using titanium or 4130 chromoly tubes for bicycle frames, I will be practicing on .035" wall thickness DOM cold rolled steel tubing.

    The best source of tubing that I have found so far online is the 1" OD, .035" wall DOM steel tube here which is $2.73/foot. I think that I can find some CREW (Cold Rolled Electric Welded) tubing locally for cheaper; I don't care if the practice weldments have seams. One of my first stops in my local search will be a muffler shop.

    I am choosing .035" wall thickness because many double butted bicycle tube frames are .9mm (.0354") at the ends. The 4130 chromoly is so much easier to weld, so welding on the cheap DOM or CREW tubing will always be easier than welding on the nice bicycle tubes.

    I brought back some CREW tubing from United Bicycle Institute that is .070" (pictured below). It was mitered in a vertical milling machine at 60 degrees. While this is what we practiced on at the school, I think that the .070" wall is too thick for practicing for a task which calls for .035"-.049" tubing.

    Click image for larger version

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    Last edited by commuter ebikes; 06-25-2018, 08:50 AM.

    My specific settings for the .035"-.049" steel tubing are as follows:

    160A peak, 1.8 pulses per second, 30% on time (pulse ratio) and 10% background current. 1/16" diameter, 1% lanthanated tungsten electrode ground to approximately 30 degrees with the tip not blunted. Argon flow (for practice welding) is 15 cfh. Series 20 water cooled torch with a gas lens and #12 cup. Filler material is .040" ER70S-2.

    The ranges within which I may experiment:
    150A-200A peak, 1.4-2.2 pulses per second, 20-35% on time, 1% lanthanated, ceriated or thoriated .040" or 1/16" (.063") diameter electrode, 30 to 60 degree angle on the electrode with tip either blunted or not, Argon flow 15-25 cfh, #8-#16 cup.

    The fixed settings:
    Always pure argon, pulse welding, gas lens, 10% background current, and laywire technique.
    Last edited by commuter ebikes; 06-25-2018, 12:06 PM.


      For hand mitering, I use aviation snips and half round files.

      Here are some free, online tube notching programs. They all operate in a browser.

      The last link is what Nova Cycles recommends.
      Last edited by commuter ebikes; 06-25-2018, 09:01 AM.


        After trimming the tubes with aviation snips and filing the miter cuts with half round files, I put them in a tube block in the bench vise for sanding with 80 grit emery cloth. I sanded the inside of the tubes with the emery cloth against the half round file so that the emery cloth would conform to the inside of the tube.

        I am using a Miller ArcStation 60SX Welding Table with its 6-inch X-Clamps to hold down the weldment for the tack welds.

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        Last edited by commuter ebikes; 06-25-2018, 10:36 AM.


          I forgot to list my pre- and post-flow settings. I use .2s pre and 10s post.


            Sweet! that's a great looking setup. thanks for sharing.

            I never practiced triangles. just single joints. triangles are efficient for materials, and very bike-appropriate, but, I think, will show post weld warpage less well than open sections do. spring back. maybe check that , too, if your builds have joints that are sensitive to spring back. sequence of welds affects this, as I expect you know....
            Fabrication is fun! Build something today. Show someone. Let them help. Inspire and share. Spread the desire.


              That is a really good point about warpage detection.

              I will need to practice for hundreds or thousands of hours. I should probably get scrap tubing for a lot of that practice.


                I went down to the local steel yard, and these are the prices:

                65 cents/lb. for steel scrap
                $2.50/lb. for SS scrap
                $2.00/lb. for aluminum scrap
                80 cents/foot for .065" wall, 1 1/4" diameter steel tubing remnants
                $1.50/foot for .065" wall, 1 3/4" diameter steel tubing remnants

                All of the thin walled tubing there is HREW (hot rolled electric welded) steel with a minimum thickness of .065" wall.

                I placed an order for 100' of .049" wall, 1 1/4" HREW steel tubing, but I don't know the price yet.

                Tubing less than .049" wall is not available at the yard.


                  The price from my local steel yard for 1 1/4" diameter, .049" wall HREW steel tubing is $3.49/foot when you buy at least 100'.

                  I bought 100'. It comes in 20' lengths, and they will cut each 20 footer in half for me for free. Further cutting at home will be with a hacksaw or a bandsaw.

                  This ought to be good practice for bicycle frame building. I will upload my "60 degree miter angle" notching PDF here tomorrow. I will be making the "Gruelons" pictured above which offer good practice on both acute and obtuse angles.

                  I am completely broke now, so it is a good thing that one can notch tubes by hand.

                  Regarding my financial situation, I get my overtime back after one more week. I got stuck on a desk job, and now I will resign from the desk job position due to its complete lack of overtime. Four weeks without OT took us down to bare bones.

                  My first purchase with the overtime money will be 1/16" lanthanated electrodes because all I have now is a huge stock of 3/32" lanthanated tungsten. That is too large for the thin tubing, so I am making a large number of small steel boxes and giving them to friends and family.


                    Glad you found a yard you can get suitable tube from. Those prices don't seem bad to me.

                    I just saw an episode of a terrific little PBS show called 'A craftsman's Legacy'. This episode was a visit to see custom bike maker Stephen Bilenky, showing his shop, jigs, tools, etc. I thought of you and your quest quite a lot while watching, and so came here to check in. It was S2E12, if I recall correctly. I don't think you will find it online, but you can buy an episode, I think. This show is about the little guys. Home shops, old things, low tech. I bet you would enjoy and learn from it. He

                    Your steel yard story made me smile; I can relate to that trip you made. The free half cut is really nice! On one of my very first trips to a steel yard, I bought a couple long sections of 1.5" OD 0.128 CroMo for my homebuilt car, and brought a hacksaw with me to chop in half for the ride home. What a mistake. I was still there an hour after closing. I hauled the 2nd one long, I couldn't even make 2 full cuts. Next time, I was sure to come well before closing and wait the hour extra , for the $5 cuts.

                    One of the metal supply yards I use is run by traditionalists of some type. Great place, but a bit unusual. You know, long beards, funny hats, minimal technology. I don't mean to be flippant or disrespectful, I just don't know the right 'label'. This is the one mentioned above.

                    It's neat, feels like a century ago in there. They are still using file cards, and tech from a hundred years ago. No computers. No phones used internally. Yelling, running, and notes on slips of paper. My point is about pricing, and trust when an order is made. You want a price, no problem, they will tell you when your order is ready. No credit, better have the cash. To do so, they have to dig out just the right file card, read the latest updated note in pencil, crank through some quick hand arithmetic (no calculator either) and hand off the price slip. I got a glimpse of the file cards on the order desk, and saw dates from 1930s on cards being used in 2000s. 70 years, and prices changed so few times it still fit on one card. And that one card was not all tattered. Wow.

                    My first tube order cost me about 2x what I expected. I was on a budget and that hurt. Frankly I could easily have overstretched without knowing it. So, I sympathize with how that must have felt to you. Kind of scary, you don't want to look stupid, and there are a bunch of guys behind you, perhaps, so you just dive in and order, like I did. Then get big eyes and carefully count bills when they get to you. Ok, no lunch today, but I'll get out the door with my metal ;-).

                    That pricing seemed ripe for abuse, but of course they were honest and fair. I had to totally trust strangers in a really sketchy area, not to rob me legally. They didn't. That one transaction actually gave me a lot more confidence to just go to a shop in the city; walk in and ask about services and costs. I find places not on the internet.

                    It sounds silly to say it's kind of scary buying steel. Well, to me it was, and I wouldn't be surprised if you were a bit anxious, too. City kid, in industrial, half abandoned area of Detroit in my case. Not sure I have enough money, and don't want to make a fool of myself or be taken advantage of. Not sure who to trust. Went fine.

                    New skill, check.

                    Thanks for continuing to entertain us with your journey.

                    EDIT: Here, I found at least a 'teaser' for that episode"

                    2nd edit: It's on again today at 3:30 on Create network. That's a low-def free PBS channel for me, not sure if you can get it.
                    Last edited by JPLabs; 07-02-2018, 08:11 AM.
                    Fabrication is fun! Build something today. Show someone. Let them help. Inspire and share. Spread the desire.