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Torch firing bronze clay


#1

I try to firing things made from bronze clay as I did with silver
art clay, with torch, but the result wasn’t good. Any suggestion?


#2
I try to firing things made from bronze clay as I did with silver
art clay, with torch, but the result wasn't good. Any suggestion? 

BronzClay cannot be torch fired. It must be fired in a kiln, inside
a stainless steel box, buried in carbon.

More info. can be found:

Hadar Jacobson’s blog

Info. and links on my blog

the yahoo list Metal Clay Gallery

and there are some free or inexpensive booklets out about it.

Also, read the presentations from the recent Metal Clay World
Conference, available online.

Elaine
http://www.CreativeTextureTools.com


#3

it is not fire-able by torch method. you need to use a heat sink- a
restaurant supply store carries a small “steam table insert” with a
lid- they are in general far cheaper than from a jewelry supplier and
the jewelry supply vendors are buying them from the restaurant think
you’ll make and at at least 3 to 4 inches deep. Then allow, in
choosing your depth, room for a bed of powdered charcoal to create a
reducing atmosphere in the heat sink. You’ll then need a kiln or oven
that reaches a quite high temperature (above 500- which eliminates
all electric ovens ) and leave the clay piece in the container, in
the oven as it ramps up to temperature as a kiln would- then it
requires a relatively long firing time 6-8 hours at the temperature
listed on whichever type clay you’ve bought (same with the copper
types). overall i think it is far easier and cheaper to use the raw
natural materials rather than the clays- the clays are good for kids
with no ability or the interest in designing and fabricating as it
requires basic clay use skills, but for jewelry that will last and
that will give you consistent results metal clays do not ever
recrystallise as a natural metal would thus, is never as sturdy as a
piece out of bronze, copper or silver and golds would be. The cost is
the main negative and if you don’t want to invest in a kiln (though
they allow for greater versatility in a small studio) or your metal
clay experience is a one time thing. which if you have to remake a
broken or failed firing, and are out of th fresh material, the
waiting for an order etc, make it less easy and cost effective as
just working in bronze, by making a mould melting and casting, or
fabricating out of sheet rod, etc. anyway- you need to use a heat
sink with the newer metal clay types and all the various methods
without a kil are useless on them for lsting and durable wear… rer


#4

Oh, I wanted to add that I have had more consistent results in
firing since I switched to a smaller stainless steel box.

Elaine
http://www.CreativeTextureTools.com


#5

BronzClay cannot be torch fired. It must be fired in a kiln, inside a
stainless steel box, buried in carbon.

I suppouse that the copper clay has the same problem, I need kiln to
fire it?


#6
I suppouse that the copper clay has the same problem, I need kiln
to fire it? 

You are correct.

Elaine
http://www.CreativeTextureTools.com


#7

here’s the current firing schedules for copper and bronze clays -
you have to use a kiln, stainless steel container and activated
carbon. the info i have is from whole lotta whimsy…

BC firing:

  1. in kiln on shelf (open air) firing:
    a) RA = 250F
    b) Temp = 550F
    c) hold time = 30 minutes

  2. second firing in carbon
    a) RA 1 = full speed
    b) Temp 1 = 1100F
    c) Hold 1 = 0
    d) RA 2 = 250F
    e) Temp 1 = 1490 (1516 with muffle kiln)
    f) Hold 2 = 3 hours

CC firing:
same as above for first open air firing

  1. second firing in carbon (coconut preferred)
    a) RA1 = full speed
    b) Temp = 1750F (some are firing at 1650, but most of the beta
    testers are firing at 1750)
    c) Hold = 3 hours

it’s not the instant gratification material that the silver clays
have become. being a glass artist this doesn’t bother me, my avg
firing schedules are 18-20 hrs before you can even vent the kiln to
assist in final cooling below 300 deg…