This is a drawing of my bandsaw blade welding clamp. It holds both ends aligned, and gives ample room to get in with a TIG torch. The mounting tab gets clamped to the edge of a table so the bandsaw blade can loop freely.
The set screws are there to adjust for the thickness of the blade to ensure proper clamping pressure.
I have used mine for 1/8" to 1-1/4" blades. Weld amperage should be down around 5 - 10 amps DCEN, pulsed if possible. If you do it right you only have to weld from one side.
Weld the joint, then let it cool slowly, then heat it to blue with a small torch. Pull it out of the clamp, grind the welds smooth on both sides, then put it back in the clamp, and wash the weld with a torch until blue again.
I use 308L, 316L, Inconel 625, or Hastelloy W - 0.024" filler . It makes it easier to find the weld after grinding and is much stronger. When it is tempered the second time the stainless leaves a white band down the center of the blue.
I used little 3" vise-grip, swivel-pad, C-clamps for mine. It helps to tack the swivels solid on the lower side ofthe clamp, but leave the upper swivels free so the clamp jaw will align on the balde.