I’ve made a couple of pairs of stud earrings, the first sets using
sterling posts (as the posts had a big disc, easy for a newbie to see
and solder) but the posts are very soft. I tried tapping with a nylon
mallet and ended up with flat posts Then, I tried the advice
posted here on Ganoskin, twisting the posts (also a great way to
check the solder joint!). But still didn’t find the posts were tough
enough. Given that I’m working in Argentium, I would imagine that one
option would be to use low heat to harden the earring, after
soldering? But just how horribly hard will my bezel be? Suggestions
on how to deal with earring posts would be most appreciated
Despite all the wondrous claims made for heat treating Argentium it
does not get all that hard even when the heat treating is done
perfectly. It can achieve 120-125 HV when correctly precipitation
hardened (values from the Argentium website), for comparison 18k
standard yellow gold is 150 HV when fully annealed. So even at its
hardest heat treated temper Argentium or standard sterling for that
matter is softer than a metal most smiths consider quite soft. So
while it is a very good idea to heat treat the Argentium don’t worry
about the bezel being too hard.
Yeah, torch soldering really softens up ear posts.
Twisting the ear posts to work-harden them is a really terrific way
to stiffen up soldered-on ear posts, and is the best way I know of. Do
you have a set of pin-vises? They are really cheap for a set of
them, and they can hold securely all sizes of wire and small tubing.
You really must have a set of these!
After soldering on your ear post with pad, draw a line down the ear
post with a Sharpie pen. Grip the very tip of the post with the right
sized pin vise, and tighten it up good and hard. The pin vise should
be tight enough to not allow the ear post to slip in the pin vise
collet.
Begin to twist the ear post by rotating the pin vise with your
fingers. Watch the Sharpie line start to spiral, but feel the ear
post twisting in your fingers. When you feel the metal finally
stiffen, STOP twisting. You must be sensitive to this physical change
in the metal’s feel, or you will twist the ear post right off its pad
or solder joint.
When you have completed the twisting operation, remove the pin vise
carefully, and remove the Sharpie mark with a bit of alcohol. You
will now have one super strong, stiff ear post!
I was taught to hold the post parallel inside chain nose pliers as
far in as you can get the post (ie, down as close to the earring
backplate as possible) and twist 1/4 turn…makes sure the solder
joint is true and also hardens the post…
I most often use gold posts–14ky. It is a visible selling point, is
much stronger than.925 and less allergy prone. I have not found 14k
nickel white posts to be so.
Whenever I solder a post on I harden it (after pickling, rinsing,
etc.) I grab it with a pair of flat pliers, first at the solder point
(down by the earring) and twist it one quarter turn. I then move up
the post pulling and twisting as I go. 1/4 turn each twist. About 4
twists.
This really hardens the post and tests the seam as well.
Thank you all for responding re. hardening earring posts - will try
the twisting again (I was a bit overly exuberant and managed to twist
and pull the very most tip of the post off another pair - at least my
solder joint was strong -hahaha!). Love the tip re. using a sharpie
mark down the length of the post. And very much like the suggestion
of 14 k yellow gold posts too.
Sorry for not thanking the others who responding to my questions re.
dealing with too soft earring posts and heat hardening (effects on
bezel?) for Argentium - I just found those responses in my email
folder. Very much also appreciated James B’s explanation re
differences between sterling/Argentium vs gold, re. hardness, in
terms that really made it easy to understand.
Then, I tried the advice