On Sun, 3 Mar 2019 21:16:51 -0600, Terry Coombs
wrote:

* I've read about it somewhere , but don't recall the details ... Broke
the last (nearly new) band for my horizontal , figured I have nothing to
lose but a little time , a bit of shield gas and some 'lectrons - oh ,
and I'll need to make a clamp block to keep the blade aligned as I weld
on it . Got a new blade on the way , but just got a bug to try this . I
know low amps DCEN , what filler ? Got ER70S2 ,ER70S6 (MIG wire) , ER
308/309/312 and some Invar 42 nickel/iron . The blade is an Irwin (IIRC)
bimetal 10/14 pitch . Am I going to need to anneal the weld ? O/A torch
OK for the task if it's needed ? I know I want to minimize the HAZ .

For whatever it is worth, I seem to remember a band saw with an
attached blade welder that clamped the blade in a holder with two
sections, a fixed clamp and a movable clamp. When you hit the switch
the current was applied and the spring loaded clamp moved that end of
the blade toward the fixed end of the blade, sort of like a spot
welder. There was no filler material. When the weld was finished there
was some "bead" on both sides of the blade and the welder had a small
grinding wheel attachment so that the weld "beads" could be ground
smooth. No annealing or filler metal

Earlier on we used to grind each end of the blade to a knife edge, and
then overlap the ends and silver solder them together.

Given that most band saws have large enough wheels that the blade is
not bent sharply I suspect that the joining is not a really critical
thing.

--
Cheers,
John B.