Susan Otter on wed 27 dec 00
Hi.
My name is Susan and I am an amateur intermediate potter hobbyist.
I take classes at Craft Alliance in St. Louis and I look forward to being
part of the listserv!
I need to start out with a question. I had a recipe for a glaze called
"perfect black," which I was given by another potter at Craft Alliance.
I have misplaced it. Does anyone have that glaze recipe?
Thanks to all in advance.
Susan
Yvon LeDouget on thu 28 dec 00
Bonjour Susan
I found on clayart archives this recipe submitted by Lori Wilkinson (cone 6)
Ash glaze:
Red Art : 40
Frit 3124 : 30
Ash : 30 I used sieved unwashed fireplace ash
Rutile : 4
An excellent honey gold gloss. Add 3% cobalt for perfect black.
Yvon
Susan Otter on thu 28 dec 00
Thank you!
but the name of the glaze I'm looking for is called "Perfect Black." It's not
an ash glaze and one of its finer qualities for what I need is that it
doesn't run. I don't recall all the ingredients (obviously -- smile) -- but I
know that it had no ash in it.
Thanks.
This is a very simple glaze to mix, and very smooth. It's also very
unreactive from what these VERY amateur eyes have seen as I did several test
tiles with it as the second coat, and it didn't change a bit.
In a message dated 12/28/00 9:43:43 AM, Aledouget@AOL.COM writes:
<< Bonjour Susan
I found on clayart archives this recipe submitted by Lori Wilkinson (cone 6)
Ash glaze:
Red Art : 40
Frit 3124 : 30
Ash : 30 I used sieved unwashed fireplace ash
Rutile : 4
An excellent honey gold gloss. Add 3% cobalt for perfect black.
Yvon >>
Cindy Strnad on thu 28 dec 00
Hi, Susan.
Glaze names are a bit peculiar. People change them to suit their fancy,
invent new ones, etc. Unless you know a bit more about the glaze, it's
likely that even if you get a glaze of similar name, you may not get the
same glaze. Then, they tend to be modified by each succeeding person who
uses them, so . . .
Chances are, you'll do better at getting this particular glaze by asking
around locally--in the geographical area the glaze came from, I mean.
Here's a pretty one I tested at ^6, in case it may be of use to you. It's
extremely high-gloss, and I had no running on the test bowl I used. I would
recommend that you DO NOT use it for food surfaces. I haven't had any
analyses done on it, but the oxides are high, and I'm sure some of them will
leak out in spite of the high gloss.
Because the Gerstley content is low, I think you'll be able to substitute a
boron frit successfully, if you don't have any GB.
Oil Spot ^6-9 Oxidation
EPK KAOLIN 5
CUSTER FELDSPAR 80
WHITING 5
GERSTLEY BORATE 10
Copper Carbonate 4
Manganese Dioxide 4
Cobalt Oxide 2
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
earthenv@gwtc.net
http://www.earthenvesselssd.com
Susan Otter on thu 28 dec 00
Thank you for the recipe! I may end up doing some cone 6 firing just to try
out that kind of firing. Where I am, cone 6 firing is done in an electric
kiln.
I think maybe I did leave the "cone 10" off my request except in my mind...
Thinking it isn't really useful unless I include it in the post as well. :)
Ruth Ballou on thu 28 dec 00
Perfect Black (from Penland) ^10
46.88 Custer Spar
14.51 Whiting
4.69 Soda Ash
8.93 EPK
25.00 Silica
5.13 Cobalt Carbonate
1.12 Chrome
3.35 RIO
This glaze does not move and stays black in salt firings. Semi gloss. We
used it primarily as a decorating glaze (with 4-6% bentonite it works fine
on leather hard) on the exteriors of pots. I wouldn't hazard a guess as to
its stability for surfaces coming into contact with food. That's a lot of
cobalt, along with the chrome, to hold, even though it has plenty of
alumina and silica. Having it tested by a lab is the only way to be sure.
Ruth Ballou
John Hesselberth on thu 28 dec 00
Cindy Strnad wrote:
>Here's a pretty one I tested at ^6, in case it may be of use to you. It's
>extremely high-gloss, and I had no running on the test bowl I used. I would
>recommend that you DO NOT use it for food surfaces. I haven't had any
>analyses done on it, but the oxides are high, and I'm sure some of them will
>leak out in spite of the high gloss.
>
>Because the Gerstley content is low, I think you'll be able to substitute a
>boron frit successfully, if you don't have any GB.
>
>Oil Spot ^6-9 Oxidation
>
>EPK KAOLIN 5
>CUSTER FELDSPAR 80
>WHITING 5
>GERSTLEY BORATE 10
>Copper Carbonate 4
>Manganese Dioxide 4
>Cobalt Oxide 2
Hi Cindy,
This is almost identical to a glaze published by Carlton Ball and Janice
Lovoos in their book Making Pottery without a Wheel. It is called
Metallic Black Glossy in that book. You are right that it is not very
stable. I have tested it--the results are posted on my website, URL
below--and it leaches quite a bit. I also have had trouble with it
"spitting" all over the kiln. My shelves are always covered with little
tiny dots of this glaze when I open the kiln. Needless to say, I'm not
big on it and no longer use it. Looking at the unity formula I suspect
it would do quite a bit better a cone 10 than at cone 6, but it still has
a lot of "stuff" in it. Plus the problem with GB.
Regards, John
John Hesselberth
Frog Pond Pottery
P.O. Box 88
Pocopson, PA 19366 USA
EMail: john@frogpondpottery.com web site: http://www.frogpondpottery.com
"It is, perhaps, still necessary to say that the very best glazes cannot
conceal badly shaped pots..." David Green, Pottery Glazes
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