"Rich McCarty" wrote in message
link.net...

"Harold & Susan Vordos" wrote in message
...

What Boris said. *Exactly* what Boris said. Silver solder, "real"
silver
solder, is almost identical in appearance to yellow brass.

Really? The silver solder I've used for sterling silver is, well, silver
colored. It's available in soft, medium and hard from the precious metal
dealer. The 'hardness' refers to the melting point and thus the silver
content. The color match is nearly perfect when soldering sterling with
hard
solder.

You got me there! What you use is, in a sense, silver solder. What it
really is is solder for silver.

OK, lets talk about this in a slightly different light. In industry,
there is a solder that is called "silver solder". It is a solder
comprised of silver and copper, generally with some sacrificial element,
often cadmium. It has a color similar to brass. The alloy varies, but
it runs in the area of 50% silver. It is not solder for silver. There's
a huge difference. Most people associated with the machine industry
understand what silver solder is.

I believe that one would need to make an old fashioned brass spelter to
get
a decent color match. That's obviously unnecessary as previous posters
said
a tight fitting joint and very little solder will make excellent joints.
Silver solder is not intended to fill large gaps anyway...

Right. Silver solder is not a filler material, and is most effective when
there is a proper fitting of the components.

There is no need to make any kind of spelter, silver solder will perform
exactly as indicated. Silver solder. Not solder for silver.


Do not confuse solders with 5% or so silver content with silver solder.
The only thing they have in common is the fact that silver is mentioned
in
the names of each one.


I believe that's called 'silver bearing solder'. It can be really
important
not to get solders with lead and real silver solder not mixed up. Another
tragic case of language not being useful enough for technical purposes -
isn't silver soldering actually brazing because of some special property
of
silver?. Anyway, if you heat a silver piece thats got lead solder on it up
to silver soldering temp, the lead will burn pits in the silver.

I'm not sure exactly what constitutes brazing as opposed to soldering, for
in each case the base metal is not melted, but the soldering medium is. I
get the idea that the main difference is that in brazing one can effectively
build up an area with the brazing material, whereas in soldering it is to
be discouraged, and works poorly when attempted. Where's Ernie when we
need him? g

The qualities of lead you described are exactly why one should never uses
lead with precious metals. The solvent qualities are apparent even al low
temperatures. Platinum, for example, melts at over 3,000 degrees F, but
dissolves in molten lead. It is lead's solvent quality that makes it so
useful when assaying. It is introduced to the heat in the way of
litharge, along with the appropriate fluxes for the assay in question.
The lead that is reduced from the litharge dissolves traces of precious
metals and concentrates them in the lead so they can be recovered. The
lead is once again reduced to litharge in the cupelling process, leaving
behind a button comprised of the values.

Harold