When silver should be refined?

how many time can one remelt the same silver before it should be
refined?

indefinitely…just be certain you have removed any impurities taht
are obvious ( pass a magnet over the scrap and filings before adding
to the crucible to remove ferrous trace from saw blades, particulate
matter from -say-sanding a bench block, etc. ) and remove old dross
from the crucible devoted to silver (be it fine or alloyed- I keep
all plumb metals and alloys separated) periodically by heating the
boron layer and pouring off all possible, then re-coating with clean
flux). If you want a bit of extra insurance mix a container of
refining flux and store for remelts: to 3 parts of powdered
charcoal-(activated charcoal, as is found in garden centers, or from
aquatic suppliers)- add one part of sal ammoniac - available from any
stained glass supply house as a tinning agent for soldering coppers
or irons - finely ground ( use a razor blade to chop it into powder
or passing it through a super- fine sieve a few times works well )
then keep tightly sealed against moisture as sal ammoniac is an
humectant to a large degree; that is, it draws humidity out of room
air…to combat humidity ou may add a silica gel pack and an O2
absorbent pack to the container. A pinch is all that is necessary to
yield a bright tough ingot that will recrstallise well… lack of
recrystalization being the only indication that your scrap is
diminished. The addition of an ounce of fine silver casting grain to
old scrap is indicated if you are remelting three oz. 's of silver
and in rolling it out the ingot/sheet/wire seems brittle or
incomplete areas begin to form along the lengthwise edge of your
sheet before work hardening or conversely annealing as you form the
ingot into x mill product. if you have more questions feel free to
write me off list

RER

Silly question but I have managed to get a small portion of 14k gold
dust mixed in with my sterling, can this still be sent out to be
refined at some point or should I just toss the lot? I don’t have the
capability to melt and make my own ingots quite yet. Thanks in
advance.

Rachel

Silly question but I have managed to get a small portion of 14k
gold dust mixed in with my sterling, can this still be sent out to
be refined at some point or should I just toss the lot? I don't
have the capability to melt and make my own ingots quite yet.
Thanks in advance. 

If the amount of gold is small in relation to the silver then the
silver will not suffer at all from having a bit of gold in it, in
fact gold improves the properties of silver. Keep it because a) it is
bad luck to throw away any gold; and b) one day you will melt your
first ingot or get the whole lot refined.

Cheers, Alastair

can this still be sent out to be refined at some point or should I
just toss the lot? 

Are you wanting to recover the sterling silver or gold?

Just got some new info (for me, at least), on refining silver and
re-using scrap for casting. Yesterday morning, I did my first cast
using all scrap

silver along with “silver replenisher” from United
(www.unitedpmr.com). Amazing is all I can say!! This turned out to be
the best cast I have done…ever! Yesterday I cast about thirty
pieces in four flasks, with 5% of the silver replenisher, and they
all turned out great (usually I have between 75 and 90% success rate
with re-using silver at a 50-50 new/old mix). If you are re-using old
metal, you might wanna look into this alloy, United has the patent on
it, and it is kinda pricey, but I only bought a small quantity so
didn’t get any price breaks.

So when should silver be refined?..from yesterday’s results, I am
thinking the answer would be rarely unless it is contaminated with
solder. I would truly love to hear if anyone else has any experience
with this alloy, I am learning production casting the hard way, and
glean any advice I can whenever I can from Orchid.

Tim

The sterling, I think the gold dust wasn’t enough to worry about.
But so far from the onlist and offlist responses, sounds like
refining with the gold in it shouldn’t be a problem. Thanks to all
who replied and if you know of any refiners (besided H&S) and how
much they generally want (in weight) before they are willing to
refine it please let me know.

Thanks again!
Rachel