Alisa og Claus Clausen on mon 25 jun 01
Glaze test for M. Barringer Metalic Black, cone 6, ox.
Source: Ceramics Montly, April 2001.
Tested on light, mid-range stoneware, with iron flecks. Fired to 1215c =
(22219) oxidation, at this ramp:
100c to 600c 212f to 1112f
150c to 1100c 300f to 2012f
100c to 1220c 212f to 2228f
soak at 1220c for 30 minutes =20
cool down 100c per hour to 900c (212f/1652f)=20
soak at 900c for one hour
shut off and cool down (aprox. 40 hours)
10.75 Gersltey Borate
2.07 Cobalt oxide
4.14 Copper carb.
4.14 Manganese Diox.
All raw materials, with the exception of colorants, measured up or down =
to the nearest whole decimal.
Resulted in a thick and covering metalic black. The truest black grey =
metallic black I have tried. Very
good covering and smooth surface.
Alisa in Denmark
John Hesselberth on mon 25 jun 01
on 6/25/01 11:06 AM, Alisa og Claus Clausen at aliskin@MAIL.DK wrote:
> Glaze test for M. Barringer Metalic Black, cone 6, ox.
> Source: Ceramics Montly, April 2001.
> 10.75 Gersltey Borate
> 5.48 Whiting
> 78.86 Feldspar
> 4.91 Kaolin
> 2.07 Cobalt oxide
> 4.14 Copper carb.
> 4.14 Manganese Diox.
> Resulted in a thick and covering metalic black. The truest black grey
> metallic black I have tried. Very
> good covering and smooth surface.
Just a quick note on this glaze. The recipe is virtually identical to one
published by Carlton Ball and Janet Lovoos on page 144 in their 1965 book
Pottery without a Wheel. I have tested it extensively. It is very unstable
and, for me, has a tendency to "spit" all over the kiln. It is definitely
NOT a good functional glaze, probably because it is not fully melted at cone
6 AND because it is overloaded with colorants.
Web site: http://www.frogpondpottery.com Email: email@example.com
"The life so short, the craft so long to learn." Chaucer's translation of
Hippocrates, 5th cent. B.C.