Nearly all solder is silver, although some looks grey, and some old stuff
may have rust stains on it if it's been on a rusty steel spool.

If you can wind the solder around a finger for several turns without serious
discomfort, it's soft solder.
Soft solders that contain silver are more clearly referred to as
silver-bearing solder.

Hard silver solders are hard wire, stiffer than copper wire, more like
brazing rods in stiffness. Even mild steel wire isn't as stiff as hard
solders.

Brazing is the process for joining parts with hard silver solders. Brazing
steel is identically the same operation, and if you've brazed steel, you're
familiar with red-hot temperatures, flux flowing, etc.
Oxy-acetylene or MAPP gas (used with a MAPP torch) are both capable of
brazing bandsaw blades. Some say that MAPP won't work, but I've brazed and
silver soldered steel parts with much more mass than the lap joint of a
bandsaw blade, so I know MAPP brazes. Maybe some folks don't get the right
results because of the torch that the MAPP is used with.

Silver soldering bandsaw blades can also be performed with electrical
brazing fixtures. I found an old machine specifically designed to braze
bandsaw blades with hard silver solder. The machine doesn't force the ends
of the blade stock to fuse together the way a blade resistance welder does..
it just uses electrical current to generate heat in the blade stock joint so
the flux and hard solder make a secure scarfed joint.

Electric bandsaw blade welding is generally accomplished with squared ends
being butt welded together by resistance welding.

Electric bandsaw blade brazing is approached in the same way as (gas)
brazing of the scarfed joint.

--
WB
..........


"Artemus" wrote in message
...
Obviously I'm doing something wrong here as my joints are brittle
and don't hold worth squat. I ground the ends of the blade to about
45 degrees and cleaned the ends with sandpaper. I put on plenty
of flux and wedged a small piece of silver solder in the scarf joint.
Both ends are held in a jig so nothing moves during the soldering.
The saw blade is 3/16 wide and .025 thick. I'm using oatey 53013
silver solder. I'm using a propane torch w/ pencil tip burner.
I've tried heating just till the solder melts & flows, and hotter, up to
the blade turning a cherry red. Nothing worked.
So what am I doing wrong? technique? Wrong solder?
Art