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Annealing sterling silver in the kiln


#1

I have some 24g sterling silver that I textured in the rolling mill.
It’s pretty thin and I’d hate to pick up the dreaded Fire scale so am
wondering can I avoid FS by annealing this sheet in my kiln? And
would I need to flux before placing it in the kiln?

And as long as I brought it up.does anyone have a favorite flux for
use on Sterling Silver.I use Handy Paste and Borax/denatured alcohol.
I was having great results with the borax/alcohol; however, it is
being troublesome at present (6 mo old and some natural evaporation
so I added more alcohol). Not problems with soldering just more Fire
Scale than I would like. I have been reading the recent posts on
Boric Acid/Borax. Very interesting.

Kay Cummins
www.OutAndAboutGirls.com


#2
I have some 24g sterling silver that I textured in the rolling
mill. It's pretty thin and I'd hate to pick up the dreaded Fire
scale so am wondering can I avoid FS by annealing this sheet in my
kiln? 

Unless your kiln maintains a vacuum, or a controlled oxygen free
atmosphere, then it will do the exact same thing, as regards fire
stain or fire scale, as annealing with a torch will do, so long as
we’re talking about the same temperatures. If your kiln temp is
lower, but for longer, it might be gentler. But you still need to
provide some sort of flux or other protection against oxidation.

Fire stain and fire scale are the result of heat plus oxygen plus
time. The tool used to heat the metal (torch versus kiln) isn’t the
issue.

Peter Rowe


#3

Having good luck w/ Prips Flux (Grobet), Stop-Ox and My-T Flux (both
Rio Grande). Not sure about avoiding firescale by annealing in the
kiln. Probably unavoidable, esp. w/out flux.

Kay Taylor


#4

Would the sterling sheet stay firescale free where you to put your
sheet in a stainless steel container with carbon similar to the one
used to fire bronze PMC?

Vince LaRochelle


#5
Would the sterling sheet stay firescale free where you to put your
sheet in a stainless steel container with carbon similar to the
one used to fire bronze PMC? 

no but it is better than nothing, if you combine the charcoal with a
good coating of prips flux and have a reasonably well sealed
container it will do ok.

James Binnion
James Binnion Metal Arts


#6

Hello,

While I have not actually tried this myself yet, I have researched
something along these lines…and this is where I ended up so far…

The Rio Grande catalog offers a stainless steel container, with a
lid, and also ground up charcoal.

I was told that I could bury the item in the charcoal, in the
container, to anneal in a kiln…actually in my case, I was interested
in “heat hardening” the silver.

(has anyone tried this or similar yet?)

Thanks and Best regards,
Julie


#7
(has anyone tried this or similar yet?) 

Could have, but why. All the fuss and cost of a stainless container,
burying the sheet in carbon, etc. So much easier to just put on a
proper coating of Prips flux. Quicker too, I think. Then you can
anneal with a torch, anneal with a Kiln, or heat treat however you
wish. No problems with fire stain or fire scale, which is your
desired result.

It never fails to amaze me that people, presented with a solution
that works, continue to try and make the whole process more complex
to no real good effect. Prips or similar fluxes are a proven
effective, trusted, inexpensive, relatively simple, and well
documented method that’s been taught and used in the U.S. for around
sixty years now, and much longer in Europe. When Fred Fenster taught
my sophomore class how to use it in 1972, it took just one fairly
short demonstration and we all knew it and understood it. I for one,
have found nothing superior since then, and use it the same way
still. If people wish to continue to try and invent the square and
hexagonal wheel, well, that’s their choice. Personally, I’m sticking
with the round one.

And if it’s the sprayer that turns you off, well, Richard Thomas who
taught for decades at Cranbrook, came up with a mix, only a bit more
complex to make up, which he called Ring-a-ding (after the bell that
goes off in your head when you get an inspiring good idea). That
works only for annealing, not for soldering, and is slightly less
effective at keeping the original surface polish during annealing,
but it effectively prevents fire scale and fire stain, and is a
simple dip or brush on protectant, no spray required. Metalsmith
magazine published that formula over 20 years ago. It too works, is
inexpensive, and totally simple to use.

Maybe instead of repeatedly writing about it, I should put together
kits of chemicals, sprayer, bottle, etc, for Prips, and just the
stuff for Ring-a-ding (though that one might have some sort of
copyright or trademark protection. I’d have to check. At one point,
mid '70s, Richard Thomas had a local (Detroit area, just a bit south
of Cranbrook) jewelry supplier, C.R.Hill, which is still around,
making and selling the stuff, though they tended to make it too
dilute… Perhaps one of the Detroit area Orchidians might call them
up and ask if they still have any sort of exclusivity on commercial
sales of the mix… There never were limits on mixing it yourself for
your own use.

cheers
Peter Rowe


#8

Peter,

I bought a commercial preparation of Pripps a couple of years ago -
the manufacturer is labelled “GRIFFITH by Grobet USA”.

Susan Ellenton


#9
I bought a commercial preparation of Pripps a couple of years ago
- the manufacturer is labelled "GRIFFITH by Grobet USA". 

Yup. They package pretty much the standard generic recipe. More
costly than mixing it up yourself from ingredients you’ve bought
seperately, but if you do that, as I’ve always done, you might also
have to buy more than you want. So the Griffith product is one way
to get it in smaller quantities. Their pricing is not as outlandish
as some of the things Grobet sells (like sparex pickle. an overpriced
lousy product IMHO)…

Cheers
Peter