F. Parker on fri 26 may 06
I've been trying to find a really nice high-gloss "noxema" blue and a
comparable "bottle" green for ^6 ox on a tan/beige stoneware. My "noxema"
blue (recipe below) pinholes really badly (very small pinholes). If
anyone has a couple of recipes they'd be willing to share, I'd be most
grateful. Nothing I've tried works well...
The noxema blue I'm using is:
Custer spar 48.3
Wollastonite 23.2
EPK 11.1
Gerst borate 10.1
Silica 4.5
add:
Cobalt carb 2.8
Many thanks,
Fred Parker
Brian Fistler on sat 27 may 06
On Sat, 2006-05-27 at 18:03 -0400, asim mahmood wrote:
> Brian,
> A question of soaking is bothering me and that is how to achieve a 30
> minutes soak on electric kiln controlled by Kiln Sitter. My understanding is
> that upon achieving the cone 6 temp the sitter would trip off, resultantly
> turning off the kiln and thereafter how to achieve soak. I shall anxiously
> be waiting for the response from any one indulging in clay " Yoga " to put
> my mind at ease. Thanks,
> Asim Mahmood.
Asim,
William Schran answered that question, in response to Fred, but the
answer would be to use witness cones and watch for ^6 to drop, then turn
your switches down to hold the temp, you could use a #7 cone in the
sitter as a backup. (As suggested by William S.)
Another thing you could do that might give the glaze a long enough time
to heal over would be to back off the power when cone 5 drops so the
climb to cone 6 takes much longer than usual. The idea being that if
you take an hour or more to reach cone 6 from cone 5, the temperature
isn't going to be climbing as rapidly, so not as much "new stuff" will
be boiling out, so it may be enough to allow the pinholes to heal over.
Actually you could pretty much keep the temperature steady at where cone
5 drops and allow it to soak about an hour at that temperature, (a
pyrometer would be helpful here.) as an hour of soaking at a give cone
should do the heat-work of the next higher cone, and the kiln should
shut itself off with the #6 in the sitter.
Brian
Pam Cresswell on sat 27 may 06
Try "Hanson's 5x20" as a base ( look in the archives or Digitalfire ) and
add colorants to taste. In April, our local glaze enthusiasts were
experimenting with blues, and that was my contribution. Hanson's seems to be
a good fit for a wide range of ^6 clays. I got a pretty good noxema with the
addition on 4% cobalt carb. An additional 1% or more of black iron oxide
gave it more depth and interest. Red iron oxide would probably work too.
For a bottle green, I would use the same base, and do a line blend with
copper till I got the depth of green I wanted, then with that green, do a
line blend with cobalt till I got just the right shade. Then you would have
two lovely glazes that you know would play nice together, not to mention the
base glaze as a clear.
Pam in hot in sticky KC, feeling the urge to make some glaze tests for my
little test kiln :-)
Steve Slatin on sat 27 may 06
Asim --
There are a few separate issues here -- a kiln
sitter is really best used as a fail-safe device,
turning a kiln off automatically when it fires
above your target for heat-work. This is why
many people use a cone 7 'bar' in a sitter for a
cone 6 firing.
The reason why people use sitters this way is
that they aren't enormously accurate. A tiny bit
of corrosion on the sitter drop bar, or a
pyrpmentric bar or cone not inserted quite right
can easily leave you a full cone -- or even more
-- of from where you want to be. It really is
better to use witness cones right in front of a
peep so you can see when you really have the
target cone coming down.
The other thing about a sitter, though, is it's
usually pretty easy to manually 'rearm' the
sitter when the cone or bar does bend. To do this
you push the deadfall flap back up. Usually it
'clicks' back into place, but if it doesn't you
can use a bit of tape to hold it up. Then you
can push the 'ON' button and the kiln will come
back on. Remember at this point you MUST turn
the kiln off manually, the sitter is no longer
doing anything.
Best wishes -- Steve Slatin
--- asim mahmood wrote:
> Brian,
> A question of soaking is bothering me
> and that is how to achieve a 30
> minutes soak on electric kiln controlled by
> Kiln Sitter. My understanding is
> that upon achieving the cone 6 temp the sitter
> would trip off, resultantly
> turning off the kiln and thereafter how to
> achieve soak. I shall anxiously
> be waiting for the response from any one
> indulging in clay " Yoga " to put
> my mind at ease. Thanks,
> Asim Mahmood.
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Mike Gordon on sat 27 may 06
Fred, Before going to all the trouble of changing your glaze .......
have you tried extending the length of your bisque firing? Or using a
longer soak at the end of the glaze firing to allow the pin holes to
heal over? If the color of your present glaze is the color you want and
the pin holes are the only problem you are encountering the two points
I made above might be easier solution . Just thought, Mike Gordon
On May 26, 2006, at 7:00 PM, F. Parker wrote:
> I've been trying to find a really nice high-gloss "noxema" blue and a
> comparable "bottle" green for ^6 ox on a tan/beige stoneware. My
> "noxema"
> blue (recipe below) pinholes really badly (very small pinholes). If
> anyone has a couple of recipes they'd be willing to share, I'd be most
> grateful. Nothing I've tried works well...
>
> The noxema blue I'm using is:
> Custer spar 48.3
> Wollastonite 23.2
> EPK 11.1
> Gerst borate 10.1
> Silica 4.5
> add:
> Cobalt carb 2.8
>
> Many thanks,
>
> Fred Parker
>
> _______________________________________________________________________
> _______
> 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.
>
Brian Fistler on sat 27 may 06
On Fri, 2006-05-26 at 22:00 -0400, F. Parker wrote:
[snip]
> My "noxema"
> blue (recipe below) pinholes really badly (very small pinholes).
[snip]
Fred,
Have you tried a short soak at cone 6? The pinholing could quite
possibly be to gassing still occurring when the glaze starts to cool.
By doing a soak it could allow those compounds to fully escape and the
glaze to heal-over before it starts to cool. I find a 30 minute soak to
help a lot on glazes that pinhole, especially those with very small
pinholes.
Brian
Paul Lewing on sat 27 may 06
on 5/26/06 7:00 PM, F. Parker at fhparker@PRODIGY.NET wrote:
> I've been trying to find a really nice high-gloss "noxema" blue
Fred, to get that particular shade off blue from cobalt, try a high-zinc
glaze base. There are lots of them out there. Just pick a glossy one that
fits your clay.
Paul Lewing
asim mahmood on sat 27 may 06
Brian,
A question of soaking is bothering me and that is how to achieve a 30
minutes soak on electric kiln controlled by Kiln Sitter. My understanding is
that upon achieving the cone 6 temp the sitter would trip off, resultantly
turning off the kiln and thereafter how to achieve soak. I shall anxiously
be waiting for the response from any one indulging in clay " Yoga " to put
my mind at ease. Thanks,
Asim Mahmood.
>>Fred,
>
>Have you tried a short soak at cone 6? The pinholing could quite
>possibly be to gassing still occurring when the glaze starts to cool.
>By doing a soak it could allow those compounds to fully escape and the
>glaze to heal-over before it starts to cool. I find a 30 minute soak to
>help a lot on glazes that pinhole, especially those with very small
>pinholes.
>
>Brian
>
>______________________________________________________________________________
>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.
_________________________________________________________________
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William & Susan Schran User on sat 27 may 06
On 5/27/06 6:03 PM, "asim mahmood" wrote:
> how to achieve a 30
> minutes soak on electric kiln controlled by Kiln Sitter. My understanding is
> that upon achieving the cone 6 temp the sitter would trip off, resultantly
> turning off the kiln and thereafter how to achieve soak.
The simple solution is to fire using witness cones and don't use the
Kilnsitter to shut off the kiln.
This will be a more accurate way to fire and you will have a better record
(the bent cones) of your firings.
You could use a cone higher in the Sitter as an emergency back-up.
I encourage everyone to use witness cones, in both manual & programmable
kilns.
-- William "Bill" Schran
Fredericksburg, Virginia
wschran@cox.net
wschran@nvcc.edu
Dave Finkelnburg on sat 27 may 06
Fred,
Pinholing is a difficult problem. You are using
boron to make a fairly high alumina glaze smooth out
at cone 6. Boron melts at a relatively low
temperature and may trap gas from the ware or other
ingredients.
For that reason you may want to test some
different ingredients in your glaze. Here are two
glazes to try, both with 2.8% cobalt carb, that are as
close as possible to being chemically identical to
your posted glaze. Good glazing!
Dave Finkelnburg
N.Blue w/whiting
G.B. 9.7
Whiting 16.8
Cspar 51.3
EPK 9.3
Silica 12.9
N.Blue w/3134
Ferro Frit 3134 11.0
Whiting 16.6
Cspar 43.8
EPK 15.2
Silica 13.4
--- "F. Parker" wrote:
> I've been trying to find a really nice high-gloss
> "noxema" blue and a
> comparable "bottle" green for ^6 ox on a tan/beige
> stoneware. My "noxema"
> blue (recipe below) pinholes really badly (very
> small pinholes). >
> The noxema blue I'm using is:
> Custer spar 48.3
> Wollastonite 23.2
> EPK 11.1
> Gerst borate 10.1
> Silica 4.5
> Cobalt carb 2.8
__________________________________________________
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Ivor and Olive Lewis on sun 28 may 06
Dear Fred Parker,
Just looking at your recipe, I am wondering which ingredient is giving =
rise to outgasing.
Could your clay be underfired and still retain some organic residues? =
This might account for the defect.
Hope you solve things.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Jeanie Silver on sun 28 may 06
Dear Brian
Its easy to soak with a kiln sitter...
1 You have to be present when the kiln sitter goes off
2 Simply turn the kiln on again by depressing the main button.
3 Prop something (I use a tomato stake of the right height ) backed up by 2
kiln shelves leaning against.
4 Be very careful not to do something more interesting for your soak time,
so that you come back 3 hours later instead of a half hour
Jeanie in Pa.
Ron Roy on sun 28 may 06
Hi Fred,
Looks like this glaze has a bit too much alumina - try some tests with less EPK
like 9 and 7 instead of 11.1.
Alumina helps prevent running by the way so be careful and protect your
shelves when testing.
Pin holes can be the result of improper bisque firing - make sure you don't
go too fast and make sure there is excess oxygen in your kiln to help burn
off any organics. Tan clays have some iron so clean bisque is recommended.
What cone do you bisque fire to?
RR
>I've been trying to find a really nice high-gloss "noxema" blue and a
>comparable "bottle" green for ^6 ox on a tan/beige stoneware. My "noxema"
>blue (recipe below) pinholes really badly (very small pinholes). If
>anyone has a couple of recipes they'd be willing to share, I'd be most
>grateful. Nothing I've tried works well...
>
>The noxema blue I'm using is:
>Custer spar 48.3
>Wollastonite 23.2
>EPK 11.1
>Gerst borate 10.1
>Silica 4.5
>add:
>Cobalt carb 2.8
>
>Many thanks,
>
>Fred Parker
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Lynn Goodman Porcelain Pottery on mon 29 may 06
I have been at a show for a few days, and am just now catching up with
clayart.
I have a simpler solution. You still have to be around, but you
shouldn't have to prop the gate up. When the gate drops, lift it up.
Push in the button. SLOWLY bring the gate down. DON'T drop it or the
kiln will shut off again.
Then---watch the witness cones to make sure you don't overfire. I check
them every 10 minutes or so. You will have to adjust the dials
sporadically to control the temperature, but it works.
Lynn
On May 28, 2006, at 2:00 PM, Jeanie Silver wrote:
> Dear Brian
> Its easy to soak with a kiln sitter...
> 1 You have to be present when the kiln sitter goes off
> 2 Simply turn the kiln on again by depressing the main button.
> 3 Prop something (I use a tomato stake of the right height ) backed
> up by 2
> kiln shelves leaning against.
> 4 Be very careful not to do something more interesting for your soak
> time,
> so that you come back 3 hours later instead of a half hour
> Jeanie in Pa.
>
> _______________________________________________________________________
> _______
> 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.
>
>
Lynn Goodman
Fine Porcelain Pottery
548 Court St.
Brooklyn, NY 11231
718-858-6920
Cell 347-526-9805
www.lynngoodmanporcelain.com
Gary Harvey on wed 31 may 06
It is simple. After the kiln sitter clicks off, reset the kiln sitter by
raising the kiln sitters trip arm and pushing the button in the center.
(Remember the kiln is HOT use a non-flammable item to push it up) Then you
slowly lowering the arm so it will not trip the sitter or you can prop it
up some how.(Using something that will NOT burn) This over rides the
sitter. Because it is over ridden it will not trip so you must remain with
the kiln till YOU turn it off by manually tripping the arm. Allow about 30
minutes soak. I DO NOT TAKE ANY RESPONSIBLITY FOR FIRES DUE TO YOU NOT
WATCHING THE KILN EVERY MINUTE THE KILN SITTER IS OVER RIDDEN. This will be
dangerous if you are not there when you are to turn off the kiln. Gary
Harvey, Palestine TX
----- Original Message -----
From: "asim mahmood"
To:
Sent: Saturday, May 27, 2006 5:03 PM
Subject: Re: Noxema blue and bottle green?
> Brian,
> A question of soaking is bothering me and that is how to achieve a
> 30
> minutes soak on electric kiln controlled by Kiln Sitter. My understanding
> is
> that upon achieving the cone 6 temp the sitter would trip off, resultantly
> turning off the kiln and thereafter how to achieve soak. I shall anxiously
> be waiting for the response from any one indulging in clay " Yoga " to
> put
> my mind at ease. Thanks,
> Asim Mahmood.
>
>>>Fred,
>>
>>Have you tried a short soak at cone 6? The pinholing could quite
>>possibly be to gassing still occurring when the glaze starts to cool.
>>By doing a soak it could allow those compounds to fully escape and the
>>glaze to heal-over before it starts to cool. I find a 30 minute soak to
>>help a lot on glazes that pinhole, especially those with very small
>>pinholes.
>>
>>Brian
>>
>>______________________________________________________________________________
>>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.
>
> _________________________________________________________________
> Don't just search. Find. Check out the new MSN Search!
> http://search.msn.click-url.com/go/onm00200636ave/direct/01/
>
> ______________________________________________________________________________
> 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.
>
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