the temperatures at which hardening occurs, and the procedures
needed, are given in my handouts, which are on my website www.
cynthiaeid.com under FAQs, and on the Argentium Facebook group.
There are also technical guides, at the company website, under
The idea of simply letting it cool to hardening temperature, and
holding it there, is interesting----I’m not sure that anyone has
The generally accepted procedure is to heat to 580 degrees F for an
hour or so. Higher is NOT better.
The lowest temp that it works is 350 F, where it takes about 2
hours. For temperatures in between—extrapolate or take a rough
guess. the time is not critical, though it needs to be long enough,
yet not overly long. More than 3 hours could cause problems.
I usually just harden the piece at whatever state it is when it is
finished. It generally is better to do the hardening at the end,
because in addition to hardening, doing the procedure after all the
abrasive finishing processes will increase the tarnish resistance.
Hardening immediately after casting will mean that you’ll need to
have a second procedure at after finishing to increase the tarnish
resistance. (the ideal temp for that is 250F for two hours, but any
heat is helpful.) Best wishes, Cindy