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glossy blacks/cone 6/tests

updated thu 25 feb 99


Maridel Crawford-Brown on tue 23 feb 99

Hello List;
I have been testing some glossy black recipes sent to me by various people
on the list, and have not had really great luck so far finding something to
replace the one presently in use. This is, I am sure, no reflection on the
recipes, but rather something I have or have not done correctly. (Recipe
and query on the black I use presently to follow in next post).
I am putting all these over a mid-tan cone 6 stoneware clay fired to cone
6. No soaking or anything. Glaze materials thoroughly sieved when wetted
and mixed to ususal mid-milk/cream consistency.

glossy black as sent by Bill
Pot feldspar 38.18
silica 23.64
whiting 13.64
Kaolin 13.64
Zinc Oxide 10.9
add: RIO 7.27
cobalt ox. .91

looks more dark brown than black and not really glossy

another glossy black recipe given to me locally is similar:
pot felspar 43.21
kaolin 9.88
silica 23.46
whiting 11.11
GB 12.35
add: RIO 9.88
cobalt carb 2

This is also closer to a brown than a glossy black and goes greenish yellow
on the outside of a pot as does the one below.

glossy black as sent by Melody
dolomite 2.5
GB 5
whiting 7
zinc ox. .5
cornish stone 20
ball clay 7
flint 13
add:RIO 4.3
copper carb 3.0

this one seperates to a greenish yellow on the outside of a pot even when
glazed thicker and to a greenish black, with heavy metallic effects, where
thicker on inside.

Glossy black from CLAYART sent by?

Kona F-4 79
whiting 5
GB 11
add: cobalt carb 2
manganese Dioxide 4
copper carb 4

This one approachs the closest to a glossy black for me but is not uniform
in color being sort of dusty or blushed looking in some areas, and more
metallic in places. In one test it did develop some neat sort of tiny oil

Would the above glazes have been blacker using Black iron oxide?
Any hints or suggestions as what I need to do to improve any of this welcomed.

Schapansky on wed 24 feb 99

Hi Maridel;
Try this glossy black.

Albany Black cone 5 -6

75 Albany Slip (I use Alberta Slip)
20 Nepheline Syenite
5 Gerstley Borate

Add: 5 % Cobalt Oxide

Hope this helps