Kit Shannon on sat 20 nov 99
I'm looking for a nice, food safe black glaze at cone 6.
I'm firing with a white body, so I'm wondering if anyone
has used the Ron Roy black over a white body. I think i tested
it awhile ago and it wound up kinda greenish.
-any suggestions on what i could do to get a true black
on my white body.
I have a black but it has lots of manganese in it so I
don't really want to use it.
any ideas?
Kit
>
> RR c6 black #2
> -----------------
> F4 SPAR................21.00
> WHITING................6.00
> TALC........................3.00
> F3134....................26.00
> EPK........................17.00
> SILICA...................27.00
> BENTONITE...........2.00
> RED IRON OX........9.00
> coblt carb.......... 1.00
> ----------
> Total.....................112.00
>
Cindy Strnad on sun 21 nov 99
Kit,
I got the greenish color from RR black, too. One percent cobalt carb isn't
much for a black glaze, so I'm going to try doubling it. Why don't you give
that a shot, too. Or it might be cobalt oxide would work better.
Cindy Strnad
Earthen Vessels Pottery
Custer, SD
John Hesselberth on sun 21 nov 99
Kit Shannon wrote:
>-any suggestions on what i could do to get a true black
>on my white body.
Hi Kit,
I haven't tried it on a white body, but increasing the cobalt carbonate
to 2% definitely gave me a blacker black on my tan clay. It still tested
to have extremely low leaching. Give it a try.
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 time for potters to claim their proper field. Pottery in its pure
form relies neither on sculptural additions nor on pictorial decorations.
but on the counterpoint of form, design, colour, texture and the quality
of the material, all directed to a function." Michael Cardew in "Pioneer
Pottery"
Matthew Blumenthal on sun 21 nov 99
I use it on cone 6 Bmix. Isn't real black. More a dark brown with a bit of
green. You can try adding 2% cobalt carb to blacken it up a bit.
I like it a lot.
At 05:04 PM 11/20/99 -0500, you wrote:
>----------------------------Original message----------------------------
>I'm looking for a nice, food safe black glaze at cone 6.
>I'm firing with a white body, so I'm wondering if anyone
>has used the Ron Roy black over a white body. I think i tested
>it awhile ago and it wound up kinda greenish.
>-any suggestions on what i could do to get a true black
>on my white body.
>I have a black but it has lots of manganese in it so I
>don't really want to use it.
>
>any ideas?
>
>Kit
>
>
>>
>> RR c6 black #2
>> -----------------
>> F4 SPAR................21.00
>> WHITING................6.00
>> TALC........................3.00
>> F3134....................26.00
>> EPK........................17.00
>> SILICA...................27.00
>> BENTONITE...........2.00
>> RED IRON OX........9.00
>> coblt carb.......... 1.00
>> ----------
>> Total.....................112.00
>>
>
>
***********************************************
* Matthew Blumenthal *
* Fremont CA *
* Potter, Guitar Player, General Computer Nut *
* mattblum@pacbell.net *
* http://www.mattegrafix.com *
* ICQ 12691259 *
***********************************************
Veena Raghavan on sun 21 nov 99
Hi Kit,
I have used the RR Cone 6 #3 on Cone 6 porcelain and the result was
a lovely glossy black.
All the best.
Veena
Veena Raghavan
75124.2520@compuserve.com
Ron Roy on sun 21 nov 99
Hi kit
This will work fine - if it's not black enough raise the cobalt carb to 1.5
- if still not black enough raise it to 2% - the Alfred tests John H had
done said it was even better with added cobalt.
RR
>----------------------------Original message----------------------------
>I'm looking for a nice, food safe black glaze at cone 6.
>I'm firing with a white body, so I'm wondering if anyone
>has used the Ron Roy black over a white body. I think i tested
>it awhile ago and it wound up kinda greenish.
>-any suggestions on what i could do to get a true black
>on my white body.
>I have a black but it has lots of manganese in it so I
>don't really want to use it.
>
>any ideas?
>
>Kit
>
>
>>
>> RR c6 black #2
>> -----------------
>> F4 SPAR................21.00
>> WHITING................6.00
>> TALC........................3.00
>> F3134....................26.00
>> EPK........................17.00
>> SILICA...................27.00
>> BENTONITE...........2.00
>> RED IRON OX........9.00
>> coblt carb.......... 1.00
>> ----------
>> Total.....................112.00
>>
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
vikki dow on thu 25 nov 99
Sorry for the delay in responding to the question about making RR Black
blacker...
We use RR Black #3 all the time on white clay (^5 B-mix) - to both ^5 and
^6 in an electric kiln. With the added cobalt carb, it does still have a
tinge of green where thin, but it is fairly black (& translucent) overall.
It's a nice glaze.
I altered the recipe a bit to try to make it a little less shiny and a
little more opaque. I tested this one and it did come out more opaque &
"blacker" (still shiny). I have not had it tested for leaching, but I used
Hyperglaze to calculate and it is within all the limits. I had read about
using red art clay for opacity in darker glazes in Electric Kiln Ceramics,
2nd ed. You might want to play with the amounts a bit more and make your
own adjustments. Anyway, here is my adjusted version:
custer feldspar 22
whiting 4
talc 7
frit 3134 25
EPK 10
silica 23
red art clay 9
red iron oxide 9
cobalt carbonate 2
bentonite 2
(we haven't used the bentonite)
Have fun testing!
Vikki
Stilltree Pottery
Berkeley, CA
Ron Roy on sat 27 nov 99
Hi Vikki - RR here.
Thanks for posting this - good thinking.
You would have gotten the same result by just adding another 3.5 EPK
according to my calculations.
I'm not being critical - just making an observation. Red Art does vary
(more than EPK) but I don't think enough to make any significant difference
in this glaze.
RR
>----------------------------Original message----------------------------
>Sorry for the delay in responding to the question about making RR Black
>blacker...
>
>We use RR Black #3 all the time on white clay (^5 B-mix) - to both ^5 and
>^6 in an electric kiln. With the added cobalt carb, it does still have a
>tinge of green where thin, but it is fairly black (& translucent) overall.
>It's a nice glaze.
>
>I altered the recipe a bit to try to make it a little less shiny and a
>little more opaque. I tested this one and it did come out more opaque &
>"blacker" (still shiny). I have not had it tested for leaching, but I used
>Hyperglaze to calculate and it is within all the limits. I had read about
>using red art clay for opacity in darker glazes in Electric Kiln Ceramics,
>2nd ed. You might want to play with the amounts a bit more and make your
>own adjustments. Anyway, here is my adjusted version:
>
>custer feldspar 22
>whiting 4
>talc 7
>frit 3134 25
>EPK 10
>silica 23
>red art clay 9
>
>red iron oxide 9
>cobalt carbonate 2
>bentonite 2
>(we haven't used the bentonite)
>Have fun testing!
>Vikki
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
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