Marc,
Silver solder is a misleading term, there is low temp silver bearing solder and high temp silver bearing solder called silver brazing solder.
The flex shafts are silver brazed, silver soft solder doesnt have much strength. I do mine in a lathe, bore out the stub shaft, prep the flex to go in the stub shaft, put the stub shaft in a bushing in the tailstock so that it will rotate freely and the flex in the chuck, Tin both ends with silver braze and heat and rotate the joint at low speed and gently push them together, let cool and buff down the weld to the proper diameter at a high rpm. It may take a few to get the hang of it.
My homemade shafts work fine on everything but my riggers, the hopping will break them after a period of time so I buy my shafts for them as they last better. I use 45 percent silver braze and paste flux for mine, available at a welding supply house.
mike sr
