Burness Speakman on wed 15 oct 03
From this book, why are all my blues coming out a crappy olive drab green
with tinges of blue? Is it my rutile, my firing, my temperature, my soak or
lack thereof. Someone speak to me of these things. They are ugly.
Bunny
John Hesselberth on wed 15 oct 03
On Wednesday, October 15, 2003, at 08:15 AM, Burness Speakman wrote:
> From this book, why are all my blues coming out a crappy olive drab
> green
> with tinges of blue? Is it my rutile, my firing, my temperature, my
> soak or
> lack thereof. Someone speak to me of these things. They are ugly.
>
> Bunny
>
Please be a bit more patient, Bunny. We heard you the first time. We
can't always respond to your questions instantaneously. I think we
have already offered a couple things to try that apparently crossed in
the mail. If they don't work we'll suggest some other things.
Regards,
John
http://www.frogpondpottery.com
http://www.masteringglazes.com
Scott Ackerman on wed 15 oct 03
Bunny,
My guess is that you are using cobalt oxide/carbonate and red iron oxide
with rutile added. If this is the case try doing a line blend between =
just
the cobalt/iron and the cobalt/iron with rutile. I have found out the =
hard
way that sometimes cobalt and iron with rutile will turn green when too =
much
rutile is present. 1% too much rutile can push blue to "icky" green. I =
found
this out after making several test batches and then buying a new lot of
rutile and mixing 5 gallons of glaze. To my surprise I found that the =
new
batch of rutile was much stronger than the batch that I had tested with.
Learned a very important lesson, always mix a test batch with the new
materials before mixing 25 lbs. of glaze.
"Every improvement in the standard of work men do is followed swiftly =
and
inevitably by an improvement in the men who do it" - William Morris
=20
Scott Ackerman
1133 Riverside
Suite B
Fort Collins, CO 80524
970-231-9035
-----Original Message-----
From this book, why are all my blues coming out a crappy olive drab =
green
with tinges of blue? Is it my rutile, my firing, my temperature, my soak =
or
lack thereof. Someone speak to me of these things. They are ugly.
Bunny
Chris Schafale on wed 15 oct 03
Bunny,
It would help if you provided more information. Which
glazes are you talking about? What claybody are you
using? What temperature and/or cone are you firing
to? How fast are you cooling? How much rutile are
you using? How much cobalt? Did you modify the
recipes in any way? (substituting materials, for
instance) How thick are you applying the glazes? By
dipping, pouring, or brushing? All of these things could
affect your results. If you want help, give us something
to work with!
Without knowing the answers to any of this, I suspect
that your problem is that you are applying the glazes
too thin -- when I try to make cobalt/rutile glazes green
(on purpose!) I find that thinner makes green and
thicker makes blue. Do you find that the drips are the
places where you see the hints of blue? If so, try
taking some water off the glaze and firing again.
Another strong possibility is clay body. I have found
that some cobalt/rutile glazes look lousy on white
stoneware, even though they look great on brown
stoneware or porcelain.
Happy testing!
Chris
On 15 Oct 2003 at 8:15, Burness Speakman wrote:
>From this book, why are all my blues coming out a
crappy olive drab green
with tinges of blue? Is it my rutile, my firing, my
temperature, my soak or
lack thereof. Someone speak to me of these things.
They are ugly.
Bunny
____________________________________________
__________________________________
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your
subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be
reached at melpots@pclink.com.
Light One Candle Pottery
Fuquay-Varina, North Carolina, USA
(south of Raleigh)
candle@intrex.net
http://www.lightonecandle.com
| |
|
