On Fri, 13 Jan 2006 17:08:40 -0600, "Robert Swinney"
wrote:


Good silver solder for steam engine work is 96% tin, 4% silver. It has melt
point of around 430 deg. I think. Harris Stay-Bright is a common brand..
Technically it is known as "silver bearing solder", I suppose because of the
relatively low silver content. It is used with zinc chloride / hydrochloric
acid flux, sold by Harris as "Stay Clean". PM Research specifies this type
of silver solder in their boiler kits - I recently built one. I'm not sure
about the "official" silver solder for jewelry work but 96/4 silver bearing
solder has worked well for minor jewelry repairs I have made. Incidentally,
96/4 is sold by Radio Shack as silver bearing solder.

The higher temp stuff, 800 degrees and higher is known as silver braze. It
is typically of high silver content, ranging upwards to 45% silver. Costly!
It is very strong - weld strength - probably wasted strength for jewelry
work though. Besides the higher temp would make it harder to handle without
damage to the jewelry.

Bob Swinney

Stay-Brite is good stuff, but silver brazing is about 5X stronger.
Stay-Brite does give a nice colormatch with stainless. Brownell's
offers a silverbrazing alloy they say is a good colormatch with
stainless. I haven't tried it.
http://tinyurl.com/b57yr

There are two flavors of StayBrite: the regular stuff and StayBrite
8. Regular StayBrite is very fluid, almost like water. StayBrite 8
has a plastic range so it is possible to get some buildup if desired.

One troy ounce of real silversolder (several feet of 1/16" dia) will
make a lot of joints!

Ordinary soldering tools (irons, propane or butane torch) are fine
with StayBrite. You need oxy-fuel for silver-brazing. I really
like the Meco Midget torch running oxy-acetylene.

http://www.tinmantech.com/html/meco_midget_torch.php

This inexpensive torch may look like a toy, but I can assure you it
definitely does not work like a toy. It is an excellent tool.
It's the torch I use 90% of the time for silverbrazing and for
welding thin aluminum.

The Smith Little Torch is better for very small work, as in jewellry.
The Meco Midget #0 tip is about equivalent to a Litttle Torch #4 tip.