I am a “lurker” who has had many potential questions answered before
I could ask them. I have not seen anything on a problem I
encountered this past week so if anyone can help I would appreciate
it.
I was making my first attempt to pour a silver wire ingot in an
attempt to make some wire. I used a new crucible that I fluxed with
boric acid powder. Using an ounce and a half of sterling scraps I
successfully melted the silver and poured it into the cast iron
mould that had been oiled with mineral oil and heated slightly. I
kept the flame on the silver at all times during the melting and
while pouring to prevent oxidation.
Here is the problem. The ingot is so hard that I could only saw it
with great difficulty. Tried to stamp it with the sterling stamp and
it would not make an impression at all. I tried annealing it in a
kiln at 1200 degrees for 15 minutes than cooled it slightly, than
put it into pickle. I now have a silver ingot that acts like mild
steel, it will not bend or flex and is impossible to run it through
a mill.
Any ideas on what may have happened will be appreciated.
Ronald Neldner
@ronald