Silver solder is quite strong, we use it for soldering copper pipe in Oxygen services. Normal Oxygen pressure is about 15 bar.I have always used the welders built into some bandsaws, but I have seen silver solder used a couple of times. In each case, the guy joining the blade ends ground a taper on the flat side of each blade where they joined. I think it was about 1/4-inch of taper on each end. Then he put lots of borax on the joint and heated it with a torch until it was red before adding the silver solder. I was skeptical about the strength of a soldered bandsaw blade joint, apparently it works well if done correctly.
Regards,
Dave