Anne K. Wellings on mon 15 sep 03
Ron and John (and anyone else.....),
I am testing Glossy Base I from your book with different colorant
combinations. I am using rutile for both color and variegation. I know
you use a lot of rutile, but I can't find where it says what kind you
use. I am assuming you use the regular dark milled rutile since I've read
it is supposed to give more mottling, etc.
I have recently purchased what was supposed to be "milled rutile" but
looks more to me like the light "ceramic grade" rutile. The supplier says
they gave me what I asked for but it's lighter than the last stuff I got
from them, and is the same color as an old bag of the light stuff I have
sitting around. I used some of it in a small batch along with mostly the
dark stuff, a total of 9% rutile for a variegated gold-yellow glaze. I
don't see a whole lot of difference, if any, from my original test with
only the dark stuff, but would like some feedback before I mix up more
with only the new stuff.
I have searched the archives and other places and haven't gotten
definitive answers. Is there a lot of difference in results (color and
variegation) between the two types? Is the dark "milled" harder to get
these days, and does it vary in color from time to time? Should I not
worry about it and just keep using whatever kind I can get? And what kind
do you use?
Thanks,
Anne Wellings
Sunrise Beach Pottery
Olympia, Washington
John Hesselberth on mon 15 sep 03
On Monday, September 15, 2003, at 02:05 PM, Anne K. Wellings wrote:
> I am testing Glossy Base I from your book with different colorant
> combinations. I am using rutile for both color and variegation. I know
> you use a lot of rutile, but I can't find where it says what kind you
> use. I am assuming you use the regular dark milled rutile since I've
> read
> it is supposed to give more mottling, etc.
Hi Ann,
We used dark rutile for most of the recipe development in MC6G;
however, I have since tested several other rutile types and haven't
seen a huge difference. The one exception might be in the zinc base
were we show the glaze turning from blue to green as the rutile is
increased from 4.5% to 6%. Some have had to use more rutile that 6% to
get the green color.
Some glazes are apparently more critical than others, though. If
Richard Aerni is currently on Clayart, I think he will say that his
glazes are extremely critical to rutile type. He pays considerable
attention to that aspect of glazing.
Regards,
John
http://www.frogpondpottery.com
http://www.masteringglazes.com
Louis Katz on mon 15 sep 03
Unfortunately there is lots of variation in rutile. Not only does its
iron content vary but so does its unfired color, seemingly
independently of iron content. I strongly suggest that you buy rutile
in large quantities maybe even a lifetime's worth. If you don't every
time you run out you may have this problem.
Louis
On another subject.
It has been really nice having the 1950's issues of CM on disk. I have
had two student requests for information today that I have found on
them. Well worth the $25 it cost.
On Monday, September 15, 2003, at 01:05 PM, Anne K. Wellings wrote:
> Ron and John (and anyone else.....),
>
> I am testing Glossy Base I from your book with different colorant
> combinations. I am using rutile for both color and variegation. I know
> you use a lot of rutile, but I can't find where it says what kind you
> use. I am assuming you use the regular dark milled rutile since I've
> read
> it is supposed to give more mottling, etc.
>
> I have recently purchased what was supposed to be "milled rutile" but
> looks more to me like the light "ceramic grade" rutile. The supplier
> says
> they gave me what I asked for but it's lighter than the last stuff I
> got
> from them, and is the same color as an old bag of the light stuff I
> have
> sitting around. I used some of it in a small batch along with mostly
> the
> dark stuff, a total of 9% rutile for a variegated gold-yellow glaze. I
> don't see a whole lot of difference, if any, from my original test
> with
> only the dark stuff, but would like some feedback before I mix up more
> with only the new stuff.
>
> I have searched the archives and other places and haven't gotten
> definitive answers. Is there a lot of difference in results (color and
> variegation) between the two types? Is the dark "milled" harder to get
> these days, and does it vary in color from time to time? Should I not
> worry about it and just keep using whatever kind I can get? And what
> kind
> do you use?
>
> Thanks,
> Anne Wellings
> Sunrise Beach Pottery
> Olympia, Washington
>
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