I just returned from a trip and have been scanning the 345
E-Mails. I think you may have some process problems. How long
are your firings? Also your temperature seems
excessively high. I have enameled on Copper with fine silver
wires which will disapear at 1475 F. so have been using 1450 F.
for ALL enameling eversince, for over 35 years. Going any higher
is just not really necessary. Firing is a matter of both time
and temperature and conservative here is the best in the long
run. Try a bit longer at a lower temperature and you will gain
much in control. Think you may have over heated the 20 ga.
sterling. Fine Silver will hold up better, also I suggest using
only 18 ga. for cloisonne’. I realise that doming should take
care of the tension between the upper enamel and the counter. But
maybe it was just a tad large in size for the thickness of the
sterling in porportion. I realize that 18 ga. will add more
weight, but will also add eons to the wearability and longevity
of your work. After all you are putting in major time, which
should reflect your integrity as an artist to produce a work that
will hold up for 1000 years or more! I have seen cloisonne’
pieces in museums that look like new even though they are 800
years old or more!
As for using mica, it just won’t work to back a domed piece.
Mica doesn’t bend, especially a compound curve. You also then
would not be able to counter enamel as it would be sticking to
the mica. Ugh! A mess. Speaking of counter enamel, what did you
mean when you said you counter enameled each time? Try just
applying the flux to the front surface after preparation of the
sterling, fire, apply counter enamel to back, fire, apply wires,
fire, add enamels to cloisons, fire and complete piece. I only
apply counter once. But I apply the counter almost as thick as
I think the finished top layer will be. It is not necessary on
a domed piece to have the counter enamel exactly the same
thickness as the top side since the curved surface of the dome
should alleviate any stress between
the metal and enamel.
I usually fire around 3 minutes depending upon the type of
enamel I am using. Best to look, or take a peek, after 2.5
minutes. Some enamels may take much longer to mature. Just ask
more questions as it’s the only way to learn and good firing,