[Clayart] Homemade Cone 5 and 6

David Woof woofpots at hotmail.com
Tue Apr 12 05:21:31 UTC 2022

Hi David, ran mcc, everyone,
David asked ran mcc: "You aren't fearing a zombie apocalypse where commercial cones will be
are you?
Come what may or may not regarding zombies and hard times, there may be a time when we have no cones available and what I'm thinking of now are the "draw rings" we pulled from our wood fired kilns to discern the  sodium/clay interaction build up.                                                                                                                                         And in some cases, myself included, we pulled rings to note when our glazes had matured.

Taking note to read the color of the kiln interior atmosphere, (not color of the flame) with charting and experience, lets one know about when to begin pulling draw rings.
 ***Cones if you have them, are a good learning reference during this time of learning to read the kiln atmosphere.

Back when, I thought what David H was doing with his making cones experiments was "way cool" but just filed it away as a vicarious experience for me.
 I have, and do make "Sag Bars" to test clay body deformation points in the formulations I'm experimenting with.
All the above similar and related to this topic.

FYI.....The draw rings are formed and stabilized with a wider flattened base, coated with alumina for no sticking, and lifted out thru a loose brick peep hole with a long 3/8th-inch diameter iron rod.

Who/what can stop anyone who makes an intimate study of our materials, and thinks and asks; "what would happen if?"


Woof.................. I asked my Muse if zombies will buy pottery....the little Vixen just walked away and after she muttered "stupid question."   I think she said " well old man if you survive me you don't have to be concerned about zombies."   <);>0)=={=======<
From: Clayart <clayart-bounces at lists.clayartworld.com> on behalf of David Hendley <farmpots at eastex.net>
Sent: Saturday, April 9, 2022 7:55 PM
To: clayart at lists.clayartworld.com <clayart at lists.clayartworld.com>
Subject: Re: [Clayart] Homemade Cone 5 and 6

On 4/8/2022 12:16 PM, ran mcc wrote:
> Does anyone have a recipe for homemade cone 5 and 6 cones?

Randy, I formulated recipes for homemade cones about 20 years ago. I
could make
accurate cones (tested by firing along side commercial Orton cones).
One point to remember: Size of the cone is important. I made plaster
molds from
Orton cones for mine. If your comes are smaller they will bend too early and
verse visa.

Since I fire at cone 10, I have good recipes for cones 8, 9, and 10.
But, I think
you could interpolate from them to make cone 5 and 6 cones.
The basic idea in this temperature range is that, in the formula, SiO2
is approximately
equal to the cone number and Al2O3 is approximately 10% of the SiO2.

So, my cone 8 is:
CaO  .68
MgO  .02
K2O  .22
Na2O  .09
Al2O3  .84
SiO2  8.41

The recipe is:
Custer feldspar  25.27
whiting  9.39
OM#4 ball clay  27.04
silica  38.31

Cone 10 is:
CaO  .67
MgO  .03
K2O  .21
Na2O  .08
Al2O3  1.25
Si02  10.02

So, to formulate cone 5 and/or 6, start with the formula and set the
alumina and
silica in relationship to the cone number.
I don't think it matters too much which fluxes are involved. I simply
used the
same four ingredients, feldspar, whiting, ball clay, and silica, for all
the cone
numbers, and they determined the combination of fluxes.

May I ask why you want to do this?
I did it just to see if I could, and to get a better understanding about
and they way they work.
You aren't fearing a zombie apocalypse where commercial cones will be
are you?

David Hendley
david at farmpots.com
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