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  • Joining a band saw blade

    My band saw (converted wood saw) has no blade welder and I want to make some blades from some coil stock I got at auction recently. I have a fixture for gas welding or brazing, access to oxy/acetylene and propane, and an old AC arc welder. I have joined blades with moderate success in the past, but since I want to make several in a batch, I thought I would bring up the subject.
    I suspect my arc welder would be a hassle by the time I made a jig and figured out what setting to use for the various width blades (1/4 to 5/8 inch).
    Brazing rod with the acetylene would work and maybe even with the propane torch. There seems to be quite a following for using silver solder, but my attempts to use it just beaded up the solder and it didn't flow out (wrong flux for the joint?). I think gas welding risks burning the carbon out of the hard edge carbon steel blades and making the joint brittle. I do know to cool the joint slowly enough to stress relieve the joint.
    So, use brass or silver solder? How long of a scarf joint would make the ideal joint? Would you use acetylene or propane?

  • #2
    Originally posted by Gary Paine View Post
    My band saw (converted wood saw) has no blade welder and I want to make some blades from some coil stock I got at auction recently. I have a fixture for gas welding or brazing, access to oxy/acetylene and propane, and an old AC arc welder. I have joined blades with moderate success in the past, but since I want to make several in a batch, I thought I would bring up the subject.
    I suspect my arc welder would be a hassle by the time I made a jig and figured out what setting to use for the various width blades (1/4 to 5/8 inch).
    Brazing rod with the acetylene would work and maybe even with the propane torch. There seems to be quite a following for using silver solder, but my attempts to use it just beaded up the solder and it didn't flow out (wrong flux for the joint?). I think gas welding risks burning the carbon out of the hard edge carbon steel blades and making the joint brittle. I do know to cool the joint slowly enough to stress relieve the joint.
    So, use brass or silver solder? How long of a scarf joint would make the ideal joint? Would you use acetylene or propane?
    I've always used silver solder. Propane and A/O both work.

    A 10 to 1 scarf has always been useful for me. But I just eyeball it and then smooth the joint on the bench grinder until the joint passes the guides without a catch.

    Regarding "beading up", Clean, grind clean, acid clean, then clean some more. ;-)

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    • #3
      The "official" way to make bandsaw blades from coiled stock is resistance butt welding as performed by the kind of welder you find on the side of better contouring metal cutting bandsaws. I've used band saw blades joined by every conceivable method but I prefer resistance butt weld if at all possible. My experience is the resistance welded band properly done is as strong as the parent band stock and if done really right no teeth are damaged in the weld zone.

      People of wide practical experience tell me a sil-brazed and or a MIG weld is just as good but again, that hasn't been my experience.

      My suggestion is to scout up someone with a band welder and coax or rent time on it. Once your get rolling you can cut, weld, temper, de-flash, and grind flush a saw band in a couple minutes, no more than five anyway. The typicasl band welder's built-in grinder sucks. A fine grit parting wheel in a 4" angle grinder is my go-to band dressing tool. That and a board with 4 flat head screw just above flush as a handy band holding thang.
      Last edited by Forrest Addy; 05-23-2017, 02:11 AM.

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      • #4
        Silver solder flows and wets out well at a lower temperature. So less possible damage to the blade's metal. And over the area of an 8:1 or longer scarff joint gives you LOTS of surface area for a strong joint. The big advantage of welding seems to be that on saws with that ability it's easier and faster.

        I made up a pretty typical jig for silver soldering blades a few years back and have done around half a dozen. A couple I still have and the others eventually wore out or broke in spots far away from the joints. The silver soldered joints never gave me any problem.
        Chilliwack BC, Canada

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        • #5
          Originally posted by Forrest Addy View Post
          My suggestion is to scout up someone with a band welder and coax or rent time on it.
          Or find proper tool shop with welding equipment, maybe 5-10 usd per weld depending if you want one or ten.
          Location: Helsinki, Finland, Europe

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          • #6
            A while ago was an article in home machinist? that used a mig welder with a low setting to do the butt joints. If reasonaaly proficient I think it would work well. Good luck, and let us know how it goes, Wayne.

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            • #7
              I use silver solder and have never had a properly prepared joint fail. I bevel the ends about 1/2" for a lap joint and use a simple fixture to hold the blade in alignment. I use either propane or a Prestolite torch, O/A is too much heat. I have some flat S/S I cut and place in the fluxed joint. Lacking that, flatten a piece of round and use that. I squeeze the hot joint with a pair of slip joint pliers, according to Frank McClain, this helps to anneal the joint.

              Some examples of fixtures are here;

              https://search.aol.com/aol/image?q=b...1&v_t=loki-url
              Jim H.

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              • #8
                I've had pretty good luck TIG welding a butt joint with a dab of stainless filler. Then a little dressing with grinder and file and peening the weld to straighten and work harden the weld seems to work for me. I won't argue it's the best method.

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                • #9
                  Just one method:

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                  • #10
                    Didn't we just discuss this in another thread
                    Shop made jig, TIG weld with 70S2, anneal,grind,use.....next time pay the 3.00 to have them welded

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                    • #11
                      You may want to match pitch, before starting welding..

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                      • #12
                        I have a blade welder and live in the St Louis area if it helps.

                        Be cheap I'll keep old blades and reuse good parts of bad blades.

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                        • #13
                          I know a guy who silver solders blades with no issues. Just make sure the pitch is aligned and it's straight, or there will be a bump while cutting thin metals.

                          Sent from my XT1053 using Tapatalk

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                          • #14
                            Well, thanks for all the responses. They convinced me to make the trip to the supply store and buy some quality silver solder and flux. Cost over 40 dollars, but worked so well I think it will see a lot of use on projects. Boy the right flux makes a difference! It went as smoothly as in the video. The jig in the video used De-Staco clamps like mine does but his grinding jig idea was pretty sweet. I used my tool and cutter grinder to put on the bevel, but the stick out from the vice coupled with the flexibility of the blade made the cuts less precise than if it were backed up right to the wheel, but with care it worked fine. As the video pointed out, there is finesse involved in grinding down excess solder, and I will be working on that. At any rate, the soldering was no trouble at all and all the blades came out functional, even though one is a bit over-ground..oops. Thanks again.

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