Marc Kiessling on sat 13 dec 97
Greeting All:
Does anybody know of a source for ultra fine silicon carbide powder
that Tom Buck has described in his post below. Sounds like a technique
that a few of us would like to try. " Ohhhhhh, Love those Copper Reds"
Regards, Marc
At 02:25 PM 12/10/97 EST, you wrote:
>----------------------------Original message----------------------------
>Marshall Talbot asked about using silicon carbide powder as a reducing
>agent in an electric (oxidative) kiln firing. There was a discussion of
>this topic 18 months ago (+/-) on Clayart, and one knowledgeable person
>noted that particle size of the SiC powder was a critical factor, that
>extremely sub-micron size was essential.
> I first came across this notion of SiC local reduction in Sanders
>text, Glazes for Special Effects. So I tried several firings, using a
>rather coarse SiC powder. No success. The basic problem is finding SiC so
>microfine that when it breaks down and releases carbon it does so where
>you want it to happen, viz., right alongside a copper atom. If you can
>obtain ultra fine SiC powder, then give it a try. Otherwise all you'll get
>is a lumpy green. Peace.
>
>Tom Buck ) tel: 905-389-2339
>& snailmail: 373 East 43rd St. Hamilton ON L8T 3E1 Canada
>(westend Lake Ontario, province of Ontario, Canada).
>
>
Paul Lewing on sun 14 dec 97
I got some 800 mesh and 1000 mesh silicon carbide from an abrasives
company one time. It's used in the lapidery industry for polishing
stones and other stuff. I met a guy in my booth at a show one time
who worked for an abrasives company, and he sent me a 1 lb. sample of
each grit free- enough for all of our lifetimes. If you can't find
any yourself, I'd be glad to send you a little, especially if you have
a recipe for some glaze that you've actually gotten to be copper red
with this stuff that you'd like to trade.
I thought when I got it that it was the answer to the SiC bubbling
problem, as it's hard to imagine a finer powder than the 1000 mesh.
It's so fine it will stain your hands- it's smaller than your pores.
But I must tell you, I didn't have much better luck with it than with
the 200 0r 300 mesh stuff you can get from ceramics suppliers. There
was a little less bubbling, but it certainly never did look like good
old reduction copper red.
And another question. Has anybody ever tried to reduce iron with SiC?
I've never known anybody but me who's tried that, and I've never
gotten it to work.
Later,
Paul Lewing, Seattle
Stephen Mills on sun 14 dec 97
Try firms that sell abrasive compounds and grind wheels, that's where we
get ours. Here it's known as Silicon Carbide flour, 1200 grade.
Steve
Bath
UK
In message , Marc Kiessling writes
>----------------------------Original message----------------------------
>Greeting All:
>
> Does anybody know of a source for ultra fine silicon carbide powder
>that Tom Buck has described in his post below. Sounds like a technique
>that a few of us would like to try. " Ohhhhhh, Love those Copper Reds"
>
>Regards, Marc
>
>
>At 02:25 PM 12/10/97 EST, you wrote:
>>----------------------------Original message----------------------------
>>Marshall Talbot asked about using silicon carbide powder as a reducing
>>agent in an electric (oxidative) kiln firing. There was a discussion of
>>this topic 18 months ago (+/-) on Clayart, and one knowledgeable person
>>noted that particle size of the SiC powder was a critical factor, that
>>extremely sub-micron size was essential.
>> I first came across this notion of SiC local reduction in Sanders
>>text, Glazes for Special Effects. So I tried several firings, using a
>>rather coarse SiC powder. No success. The basic problem is finding SiC so
>>microfine that when it breaks down and releases carbon it does so where
>>you want it to happen, viz., right alongside a copper atom. If you can
>>obtain ultra fine SiC powder, then give it a try. Otherwise all you'll get
>>is a lumpy green. Peace.
>>
>>Tom Buck ) tel: 905-389-2339
>>& snailmail: 373 East 43rd St. Hamilton ON L8T 3E1 Canada
>>(westend Lake Ontario, province of Ontario, Canada).
>>
>>
>
--
Steve Mills
Bath
UK
home tel: (44) (0)1225 311699
work tel: (44) (0)1225 337046
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