How do you weld a band saw blade

Machining shop

looking for tips for welding band saw blades

Contribution from teralu ┬╗Wed 4 Jun 2014, 8:31 am

Hello everybody
I'm looking for tips / tricks to weld bandsaw blades with my machine, because I can't do it with them.
About 1 year ago I bought a metal band saw (model TCM 250) with a built-in welding device. In addition I received some band saw blades but also a roll with about 25 linear meters for welding. Unfortunately I have never welded such sheets.
After 3 hours of practice and about 40 weld seams, the result is still bad. I can butt weld them with the built-in welding device, but the weld seam is very brittle. (as soon as I tighten the tape around the rollers, the weld seam breaks)

how I proceed up to now:

- Cut both ends of the tape at right angles
- Sand the surface slightly or not (I've tried both, but don't notice any difference)
- Insert the tape into the welding device and butt joint
- Adjust the width (as soon as the metal glows bright red and becomes soft, push the right welding jaw over a spring the parts 1-5mm together depending on the setting, but you have already tried that)
- let it cool down and then briefly afterglow 2-3 times (between blue and slightly dark red, the seam is much more stable, but still not good)
- Take out and grind the weld seam

Who can give me a tip on what I should do differently?

here are a few pictures of the machine and the material:

Metal band saw TCM 250 P1060712 01.jpg
Metal band saw TCM 250 P1060712 11.jpg
Metal band saw TCM 250 P1060712 13.jpg
Metal band saw TCM 250 P1060712 14.jpg
Metal band saw TCM 250 P1060712 15.jpg
Metal band saw TCM 250 P1060712 21.jpg
Metal band saw TCM 250 P1060712 22.jpg
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Lathe: .............. Schaublin 102-VM W25
Milling machine: ...... Aciera F3 W20 / F2 W20 / Rawyler TF2 W12
Grinding machine: .. Strama 75 III, Mafac K100, Tatar
Drill: ...... Aciera T10, 22VR, Cincinatti PTM MK2