This is a valuable discussion that is ongoing and has been addressed
many times, though it doesn’t hurt to keep it going.
Your instructor is only partially correct (and therefore, partially
incorrect). Sterling Silver alloys were created to produce a durable
metal. Fine silver from metal clay is less dense than Fine Silver
that has been milled (sheet/wire/etc.). Fine Silver that has been
milled is only slightly less durable than milled Sterling Silver.
Fine Silver from metal clay is about as porous as cast Fine Silver,
but, in contrast, the porosity in the metal from metal clay is even
and very fine. The conclusion one might draw from this, is that
fully sintered Fine Silver from metal clay is a modicum less durable
than milled Sterling Silver and that, compared to cast metal, it is
a little bit stronger. That is all correct.
I generally don’t recommend ring making from metal clay to my
students. However, there is an exception, in my opinion. A ring
shank (and for that matter, a cuff bracelet) that is of sufficient
thickness, would be durable and strong enough for that purpose. So,
when I’ve made rings, I always make them thicker than I would make a
comparable design from milled sheet or wire.
There are two steps that I consider essential. The first is to
always fire metal clay in a kiln. I know that there are metal clay
users who swear by torch-firing, but I do not think that this
produces a strong product. The second critical step in firing Fine
Silver metal clay to create a stronger product, is to fire at the
highest temperature for the longest duration (1650 degrees F for two
hours), disregarding the manufacturers’ low temp/short firing
schedules. This produces the strongest post-fired metal. The
critical finishing step for ALL fired metal clay is tumbling with
steel shot. This will surface burnish/compress and create a somewhat
more durable jewel.
Now, all of that being said, it is likely that wearing a ring made
from metal clay will produce wear, surface-burnishing or
’-compression’ (my term) where the ring is stressed, usually on the
sides and palm side of the shank, sooner than those areas would show
wear in milled Sterling or Fine Silver. The bezel area does not seem
to be as prone to this.
Fine Silver metal clay is excellent for any number applications and
is good for ring making, though not excellent. You are fortunate
that you have other jewelry making skills that you can use in
conjunction with your metal clay skills (and your soon to be
acquired certification). Fine silver makes for a very beautiful
jewelry object and should not be discarded as a material for this
purpose, as long as the limits of the material are taken into
consideration, AS WITH ANY MATERIAL USED FOR JEWELRY MAKING.
Note: I’ve found that many who have been schooled in traditional
jewelry making techniques are skeptical of the use of this
relatively new kid on the block, metal clay, even though it’s now
been available for almost fourteen years in the US and is now being
used internationally as well. If your instructor has not already
taken a class in the use of metal clay, you might step up and
encourage her to do so (or demonstrate the wonders of metal clay to
her). This ‘tool’, metal clay, is a useful and intriguing adventure
in object-making and has formed an integral part of the repertoire
of that I use to make my work (been working as a jeweler
since 1978; using and teaching the use of metal clay since 1996).
Hope this is helpful,