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## minimum cone for sintering cone 10 glazes

### Fredrick Paget on sat 16 sep 06

I have taken glazed pieces to the Tozan kiln in B.C. from my place in
California after sintering them to cone 04. The clay and glazes were
for cone 10 and the glaze got nice and hard so I could pack the ware
for the two day auto trip. Fired with no difference from fresh
glazed stuff.
I am also experimented with shrink wrapping a couple of small pieces
for the Flagstaff Woodfire Conference coming up to see what happens.
Fred Paget
--
Twin Dragon Studio
Mill Valley, CA, USA

### Taylor Hendrix on sat 16 sep 06

Howdy all,

I'm taking a short break from throwing my butt off to ask a question
of the collective.

Because I am going to be taking pieces to AZ for the woofire
conference, I need to make any glazed bisque hold up to the travel.
My question is this: will an 012 firing be enough to sinter typical
glossy, semiglossy cone 10 glazes to bisqueware?

not good for woodfiring.

BTW, I'm getting really really tired of bowls.

--
Taylor, in Rockport TX
http://wirerabbit.blogspot.com
http://wirerabbitpots.blogspot.com

http://clayartmugshots.blogspot.com

### Paul Herman on sat 16 sep 06

Hi Taylor,

Will it sinter, you ask. According to Cardew, sintering has been
systematically studied.

He gives the formula for the Tammann Temperature, which is 0.55 to
0.6 of the Absolute temperature of fusion. It's measured in degrees
Kelvin, which starts as zero, at Absolute zero.

The glazes are for cone ten I assume. Cone 10 is 1305 degrees C, and
by adding 273 becomes 1678 K.

1678 X 0.6 = 1006.8 (the Tamman temperature)

So, 012 is 875 degrees C, and by adding 273 becomes 1148 degrees K.

It looks like you are in the range for successful sintering.

Best,

Paul Herman

Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com

On Sep 16, 2006, at 12:01 PM, Taylor Hendrix wrote:

> Howdy all,
>
> I'm taking a short break from throwing my butt off to ask a question
> of the collective.
>
> Because I am going to be taking pieces to AZ for the woofire
> conference, I need to make any glazed bisque hold up to the travel.
> My question is this: will an 012 firing be enough to sinter typical
> glossy, semiglossy cone 10 glazes to bisqueware?
>
> Oh yeah, I'm using Armadillo's Balcones. Please nobody tell me it's
> not good for woodfiring.
>
> BTW, I'm getting really really tired of bowls.
>
> --
> Taylor, in Rockport TX
> http://wirerabbit.blogspot.com
> http://wirerabbitpots.blogspot.com

### Ivor and Olive Lewis on sun 17 sep 06

Dear Taylor Hendrix ,

Michael Cardew (p64) gives a formula for calculating the minimum =
temperature at which any substance will commence to sinter. Look up =
"Tamman Temperature". Calculate for the substance in your glaze recipe =
with the highest melting point for the service you need.=20

Note that if Alkali Earth Carbonates are in your recipe you have to take =
the Tamman Point for their oxides. This would seem to pose a problem.

Best regards,

Ivor Lewis.
Redhill,
South Australia.

### Ivor and Olive Lewis on sun 17 sep 06

Dear Paul Herman,=20

Please remember the Tamman Formula is applied to individual ingredients, =
not to the maturity point of the mixture of glaze ingredients. Examples =
given by Cardew make this quite clear.

Best regards,

Ivor Lewis.
Redhill,
South Australia.

### Lee Love on sun 17 sep 06

Taylor,

My sintered glazes are sometimes more fragile than they are after
application. For about 9 years, I bisqued and glazed at my studio loft at
the Northern Warehouse Artists Cooperative and then boxed up and carted my
work from there to Northern Clay Center to glaze fire. All I ever did was
wrap everything up in newspaper. Simply take baby food jars and/or 35mm
film canisters filled up with touchup glazes and a couple brushes for any
to make the glazes more durable. I never had to do this.

If you have layered glazes that give you trouble, you can wax
resist over them and the resist will hold the glazes in place.

Also, in the wood firing, you have ash and vapor that can help
with any bare spots.

--

Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi

### Taylor Hendrix on wed 27 sep 06

And Ivor wins the Golden Banana. My cone 011 firing to fix glazes did
not appear to work. My Cu Red glaze was easily scraped off and
powedered between my fingers. The other glazes appear to abbraid with
the finger allbeit in a much more reduced fashion than when raw. I
will not fire these again. If I have enough time for another go, I
will fire other glazed bisque at cone 04.

The trick would have been to have formulated slip glazes for
application to raw pots and long bisquing them just once. Ah, live
and learn. 4 short days before we leave in the truck. Driving the
entire way.

Rabbit on a wire, in Rockport TX

On 9/17/06, Ivor and Olive Lewis wrote:
> Dear Paul Herman,
>
> Please remember the Tamman Formula is applied to individual ingredients, not to the maturity point of the mixture of glaze ingredients. Examples given by Cardew make this quite clear.

### Lee Love on wed 27 sep 06

On 9/27/06, Taylor Hendrix wrote:
> And Ivor wins the Golden Banana. My cone 011 firing to fix glazes did
> not appear to work. My Cu Red glaze was easily scraped off and
> powedered between my fingers. The other glazes appear to abbraid with
> the finger allbeit in a much more reduced fashion than when raw. I
> will not fire these again. If I have enough time for another go, I
> will fire other glazed bisque at cone 04.

Taylor,

I have had the same experience. I don't think 04 will
help. A sintered glaze can be more fragile than an unsintered
one.

CMC is probably your best bet (maybe too late now.) Just
take some touch up glazes with you.

And remember, any woodkiln is worth its salt, will take
care of any bare places on the outside of the pots.
--

Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi

### Ivor and Olive Lewis on thu 28 sep 06

Dear Taylor Hendrix,=20

Not sure what this means, but since the Cyclone hit the Queensland coast =
six months ago you need a pocket of gold just to buy one at the =
supermarket \$13/\$14 a kilo art the moment. Hope your next trials are a =
success.

<not appear to work.>>

All the best and enjoy the weekend,

Ivor.

### William & Susan Schran User on thu 28 sep 06

On 9/27/06 2:38 PM, "Taylor Hendrix" wrote:

> And Ivor wins the Golden Banana. My cone 011 firing to fix glazes did
> not appear to work. My Cu Red glaze was easily scraped off and
> powedered between my fingers.

Subject got me wondering - could one spray the surface with a cheap fabric
spray starch to keep from damaging the glazed surface?

My first "ceramic" solution would be to add a gum binder to the glaze.

-- William "Bill" Schran
Fredericksburg, Virginia
wschran@cox.net
wschran@nvcc.edu

### Fredrick Paget on thu 28 sep 06

>On 9/27/06 2:38 PM, "Taylor Hendrix" wrote:
>
>> And Ivor wins the Golden Banana. My cone 011 firing to fix glazes did
>> not appear to work. My Cu Red glaze was easily scraped off and
>> powedered between my fingers.
>
>Subject got me wondering - could one spray the surface with a cheap fabric
>spray starch to keep from damaging the glazed surface?
>
>My first "ceramic" solution would be to add a gum binder to the glaze.
>
>-- William "Bill" Schran
>

Getting ready for the Wood Fire Conf.
I have found that there is considerable difference in the way
different glazes act to sintering, Some harden up and stick well at
cone 04. Others want to fall off in sheets. Shinos did not work at
all and I decided to put them on at the kiln site.

I raw glazed the top of a jug with genuine Albany slip with 5 percent
Neph. Syenite and it was loose after cone 04, brittle, and if you
press on it, comes of in big flakes. I brushed on more and shrink
wrapped it.

An ash glaze that was flaking off got a good spraying of clear
Krylon and we will see how that burns out. The protruding knob got
shrink wrapped using recycled shrink wrap and a heat gun. .We will
see how that burns off too, if they will let me put it in the kiln.

Fred Paget
--
Twin Dragon Studio
Mill Valley, CA, USA

### Taylor Hendrix on thu 28 sep 06

Hey Fred,

Great idea with the shrink wrap. I think I'll do a cling wrap version
and see if that will help keep things on.

Looking forward to seeing ClayArters there. I'll be the one with the
sideburns and the Dr Pepper had. Ain't no way I'm going to take my
John Deere cap and have Tony filtch it.

Safe trips to everyone and Bon Feu!

Tay Tay, in Rock Rock

On 9/28/06, Fredrick Paget wrote:
> I raw glazed the top of a jug with genuine Albany slip with 5 percent
> Neph. Syenite and it was loose after cone 04, brittle, and if you
> press on it, comes of in big flakes. I brushed on more and shrink
> wrapped it.

### Edouard Bastarache Inc. on thu 28 sep 06

Hey Hendrix Taylor,

my chilli joke was meant for you !!!

Edouard Bastarache
Goofos
(My nickname in Ancient Greek,
which I studied intensively.)

Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://www.flickr.com/photos/30058682@N00/

----- Original Message -----
From: "Taylor Hendrix"
To:
Sent: Thursday, September 28, 2006 2:45 PM
Subject: Re: Minimum cone for sintering cone 10
glazes

> Hey Fred,
>
> Great idea with the shrink wrap. I think I'll do
> a cling wrap version
> and see if that will help keep things on.
>
> Looking forward to seeing ClayArters there. I'll
> be the one with the
> sideburns and the Dr Pepper had. Ain't no way
> I'm going to take my
> John Deere cap and have Tony filtch it.
>
> Safe trips to everyone and Bon Feu!
>
> Tay Tay, in Rock Rock
>
> On 9/28/06, Fredrick Paget
> wrote:
>> I raw glazed the top of a jug with genuine
>> Albany slip with 5 percent
>> Neph. Syenite and it was loose after cone 04,
>> brittle, and if you
>> press on it, comes of in big flakes. I brushed
>> on more and shrink
>> wrapped it.
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
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> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be
>

### Taylor Hendrix on thu 28 sep 06

Dear Eddy,

I have eaten chilli that made the inside of my mouth peel three days
later. Good stuff. Tequila doesn't always put the fire out, but it
helps.

Taylor, on the floor in Rockport TX

On 9/28/06, Edouard Bastarache Inc. wrote:
> Hey Hendrix Taylor,
>
> my chilli joke was meant for you !!!

### Ivor and Olive Lewis on fri 29 sep 06

Dear Fredrick Paget,=20

Some facts about sintering are not made clear in potters books. This =
becomes apparent when you compare F. Hamer to Kingery et al. To ensure =
sintering has commenced and the process will be successful check that =
all of your ingredients, including those in your clay body, have a =
Tamman Point lower than your intended firing temperature.

For this technique to work for the purpose of transporting "ready to =
fire" ware to workshops, glazes must undergo what is termed Fluid Phase =
Sintering. If sintering is totally dry and there are no components that =
melt you will not get adhesion to the clay body. In addition, as I =
mentioned in my original post on the topic, in glazes which contain =
Alkali Earth Carbonates, the Tamman Temperature of their oxides, =
generated as they heat up, is above the maturity point of many glaze =
compositions. So they do not enter into a sintering reaction with other =
ingredients or the clay body. I know ! ! , this seems to contradict the =
mandate that they are fluxes and will melt when used in glazes.

Best regards,

Ivor Lewis.
Redhill,
South Australia.