Markus, if pickle is retained in these micro pores, what is the
actual harm? Most of the time, I put hot silver into hot pickle.
The metal does not warp nor crack. I slide the metal into the
pickle pot and use the lid as a shield to protect my hand. I have
done this with rings and pins, bracelets and pendants, bowls and
well you get the idea. The silver will be more malleable when
annealing if it is quenched hot.
Marilyn Smith
Markus, if pickle is retained in these micro pores, what is the actual harm? Most of the time, I put hot silver into hot pickle. The metal does not warp nor crack. I slide the metal into the pickle pot and use the lid as a shield to protect my hand. The silver will be more malleable when annealing if it is quenched hot.
Hi Marilyn,
The acid, being hygroscopic, will be reactivated on contact with
any liquid, even air humidity, and act, well, as acid. Part of
it might be trapped as copper sulfate (in case of sulphuric
acid) and leak out when humidity is present. There can be damage
to the skin, as all the copper salts are highly poisonous, and
reaction with sweat is, from my point of view, unpredictable due
to the fact that every person has a different composition, it
will differ even in the same person depending on what one has
eaten, drunk or what his/her health and hormones say. Even sweat
being slightly acidic, there can be harmful reactions. For an
example that’s easy to see, look at what happens when you mix
different acids, say sulphuric and nitric acid. It will get
really hot, if you aren’t careful, the mixture will boil and
spit at you. BTW, I once spilled a drop of concentrated nitric
acid and tried to neutralize it with 30% ammonia, it gave a nice
loud report from boiling up in a fracture of a second. If there
is someone out with a more profound knowledge of medicine, she
or he could perhaps give more on skin damage by acid
or copper salts. But I very often hear from skin reactions from
wearing jewellery, even high carat gold, and have no other
explanation. And as the skin is the largest and a very sensitive
organ and damages often only appear after months or even years,
I’d be careful. How deep the acid is deposited in the workpiece -
well, how deep are those micro pores and cracks? And washing out
with a neutralizing agent will not work, as the pores are closer
again with the piece cold. On the subject of warping, it of
course depends on the shape of the workpiece and the inherent
tensions. Take for e.g. a flat or slightly rised plate
surrounded by a rim. When you solder the rim to the plate and
quench the whole thing, it will distort, as the wire will
prolong mainly in length when heated (and shorten again on
cooling) whereas the sheet metal of the plate will prolong in
another direction. And you have fastened all together in hot
state, so there will be some conflict when it cools down and
contracts, or tries to do so. Same problem occurs in casting
large pieces. Ask someone who knows about iron casting e.g.
machine beds. This warping is not a matter of the liquid used,
but will occur with water as well. To reduce firestain, we used
a 50-50 solution of ethanol and water. Of course, quenching is
necessary to reduce grain growth and/or segregation of copper at
the grain boundaries. regards, Markus