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Annealing metals in a kiln


#1

Hi there!

I often need to anneal large (9x9 in) sheets of 18-20g metals, mostly
brass and copper, and I’m having a hard time doing it with a torch. I
don’t think that I’m fully annealing the middle of the sheet, and I’m
getting a lot of warping so that I have to hammer it all flat again
afterward, which must defeat some of the annealing before I can even
work on it. So, I’m trying to figure out how to anneal these sheets
in a kiln instead of using a torch. At the studio I rent space from,
there is a kiln for casting that I can use. I am wondering if there
is a table somewhere that shows the temperatures and times that I
would want to use for annealing various metals. Also, if anyone has
any tips or tricks regarding annealing in a kiln, I would greatly
appreciate it.

Thanks!
Melanie


#2

My vision is bad enough with such small fonts that I thought I read
about an Oxygen Bottle Killing in California.

Sounds like a B bottle is needed. Look for welding supplies in the
area, many deliver for a charge.

I know this is probably contrary to commonsense and science but I
anneal a lot of metal in my covered gas grill. I make a number of
Christmas Tree ornaments from Brass and Copper which I buy at Lowe’s
or Home Depot or any Crooked Cabinet Company in the area. The brass
rod is hardened when it is formed and the copper 8-10 ga round wire
hardens when it is coiled.

The copper readily anneals with flame but it becomes way too soft
for some of my applications. The brass anneals with the torch too
but I don’t want to invest the time in torch play. I crank up the
grill, lay a batch of metal rod on the grill, tent them with fire
brink and let them cook for an hour more or less. The brass comes
out softer but not fully annealed, same with the copper. Even heat
so even normalization. A full tank of gas costs less that one
ornament and I heat up the material for a dozen ornaments at a time.
And the metal is soft enough to hand form with just enough fight in
it to work the way my process has developed.

I could easily set up to do two or three dozen ornaments this way
but I don’t like to prep more material than I plan to use at a time.

Anyway, Happy Thanksgiving
Don Meixner


#3

ning kiln. As to control, well run the kiln thermostat at say 850 C
and then just match the colour pof the metal to thec inside kiln
colour.

If the metal will fit inside the kiln all you need is a trivet like
used for enamelling and a suitable big fork to load and unload from
the running kiln.

Now kilns as in electric have an oxidising atmosphere, so your
copper will be black when you take it out. As for how to anneal it?
just match the colour of the metal to the kiln, running say at 800
Cfor copper and 650 for brass.

Now here I have a plastic bucket with a couple of gallons of old
battery acid and drop the hot metal into that. Mind the steam! and
fumes. Metal comes out bright and shiny. Have done it that way for
yrs.