Penni Stoddart on sun 6 oct 02
I have a question regarding glaze colourants. I did some tests last week =
where I took a clear recipe I knew fit my clay body and added the =
colourants I had come into possession of.
I want to know what colours I should expect from each colourant. Is it =
even that easy? All of my tests turned out blues, greens and an =
oatmeal/speckled colour. This is with 2% colourant and then a mix of =
each glaze with each of the others. Resulting in 36 individual tests.
What I have is:
copper oxide
rutile
cobalt carb.
maganese dioxide
red iron oxide
cobalt oxide
I also used zircopax to get a white but that didn't seem to work at such =
a low percentage (was told it might).
If I try again with a higher percentage in my mixes can I expect =
different colours?
TIA
=3Do) =3Do) =3Do) =3Do) =3Do) =3Do) =3Do) =3Do) =3Do)
Penni Stoddart
Penelope's Pots
Past President for=20
Artisans London (Ont. Canada)
I live in my own little world, but it's ok... they know me here
Shopping Tip: You can get shoes for 85 cents at the bowling alley.
Ron Roy on wed 9 oct 02
Hi Penni,
What you need is the Hamer book - find the colourant - lets say CuO and the
info you want will be there - I don't think anyone is going to answer your
question because it is so BIG.
Each colour can give different colours depending on the type of glaze -
Hamer covers it very well.
"The Potters Dictionary of Materials and Techniques" by Frank and Janet
Hamer - somewhat pricey but worth every penny.
RR
>I have a question regarding glaze colourants. I did some tests last week
>where I took a clear recipe I knew fit my clay body and added the
>colourants I had come into possession of.
>I want to know what colours I should expect from each colourant. Is it
>even that easy? All of my tests turned out blues, greens and an
>oatmeal/speckled colour. This is with 2% colourant and then a mix of each
>glaze with each of the others. Resulting in 36 individual tests.
>What I have is:
>copper oxide
>rutile
>cobalt carb.
>maganese dioxide
>red iron oxide
>cobalt oxide
>
>I also used zircopax to get a white but that didn't seem to work at such a
>low percentage (was told it might).
>If I try again with a higher percentage in my mixes can I expect different
>colours?
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ababi on wed 9 oct 02
Hello Penni!
I want to add: You did not write to what cone you fire oxidation or reduction.
I want to offer: When you test with zircopax try with tin too, half amount.
After reading Hamer book or Clay and glazes for the potter by Rhodes/Hopper, You
will know more to predict the effects of the colorants.
Some hints
If you add cobalt and get violet in means that you have Magnesium in the base glaze
If Nickel gives you blue you have zinc in the base glaze
If you make many tests, and spend much time (and money) you better know what is
your base glaze: It is like buying a hot dog, try it with different salads but you don't
know what the hot dog is made of and how it will effect you when you arrive home! I
think I made a good example because a bad glaze will effect you at home too, might
take longer but will!
---------- Original Message ----------
>Hi Penni,
>What you need is the Hamer book - find the colourant - lets say CuO and the
>info you want will be there - I don't think anyone is going to answer your
>question because it is so BIG.
>Each colour can give different colours depending on the type of glaze -
>Hamer covers it very well.
>"The Potters Dictionary of Materials and Techniques" by Frank and Janet
>Hamer - somewhat pricey but worth every penny.
>RR
>>I have a question regarding glaze colourants. I did some tests last week
>>where I took a clear recipe I knew fit my clay body and added the
>>colourants I had come into possession of.
>>I want to know what colours I should expect from each colourant. Is it
>>even that easy? All of my tests turned out blues, greens and an
>>oatmeal/speckled colour. This is with 2% colourant and then a mix of each
>>glaze with each of the others. Resulting in 36 individual tests.
>>What I have is:
>>copper oxide
>>rutile
>>cobalt carb.
>>maganese dioxide
>>red iron oxide
>>cobalt oxide
>>
>>I also used zircopax to get a white but that didn't seem to work at such a
>>low percentage (was told it might).
>>If I try again with a higher percentage in my mixes can I expect different
>>colours?
>Ron Roy
>RR#4
>15084 Little Lake Road
>Brighton, Ontario
>Canada
>K0K 1H0
>Phone: 613-475-9544
>Fax: 613-475-3513
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