Oxidation when kiln annealing

I’ve been noticing lately that whenever I anneal in my kiln (a small
enameling one), the metal gets very oxidized. This happens with
metals I’d expect it from- but also with ones I don’t (argentium,
22k fusing gold, etc.)

I’m thinking there are 3 possible causes, though I may well be
missing something:

  1. kiln wash in the kiln
  2. steel kiln furniture supporting the metal
  3. it’s not a ventilated kiln

Any thoughts on this? I don’t mind especially cleaning or pickling
off the oxides, but I think annealing and then hardening the
argentium has lead to firescale in it (at least, I can’t figure out
where else the stuff came from!).

I’d really love to be able to anneal safely in the kiln, without
adding extra oxides. For heavier stock, I feel more comfortable that
the metal has annealed thoroughly in a kiln rather than under a
torch.

Thanks for any help!

Amanda
Amanda Fisher
http://www.afmetalsmith.com

I've been noticing lately that whenever I anneal in my kiln (a
small enameling one), the metal gets very oxidized. This happens
with metals I'd expect it from- but also with ones I don't
(argentium, 22k fusing gold, etc.)

Boy if you want to set up a perfect way to oxidize a metalthat can
be oxidized I can’t think of a better way to do it than in a kiln
without any kind of protective atmosphere. At a minimum you need to
coat the metal with a fire coat of some kind. What you use will
depend on how long it is in the kiln and how susceptible to oxidation
it is. Boric acid in alcohol will work for high karat gold but I
would use something stronger on the silver or copper alloys like
prips flux. Prips works quite well for this application.

Jim

James Binnion
James Binnion Metal Arts

Hi Jim, and thanks. I’ve used firecoat and had the same problem-
mostly boric acid in alcohol for gold and paste flux for other
metals, and it didn’t help appreciably. I’ll try the Pripps, though-
thank you!

Amanda

I've used firecoat and had the same problem- mostly boric acid in
alcohol for gold and paste flux for other metals, and it didn't
help appreciably. I'll try the Pripps, though- thank you! 

While it’s rather pricey, you might try Firsecoff. It may do the
trick.

Dave

While it's rather pricey, you might try Firsecoff. It may do the
trick. 

Thanks- I do have some Firescoff that I haven’t used much, and it
just could be perfect for this. Much appreciated!

Amanda