…..1280° Kilns

Pottery/Glass Workshop Retreats with Sallie Portnoy at

The Pottery Place – Dimbulah

Nestled in the Hinterlands, one and a half hours drive West of Cairns lies one of the North’s best kept secrets – the lovely township of Dimbulah, situated in the “dry country” on the edge of the Hodginson Goldfields. One hour’s drive ahead is Chillagoe, well worth a trip to view the incredible rock formations, limestone caves and marble mines, and only half an hour’s drive in the other direction one can experience a wealth of history travelling through the Goldfields and abandoned mine sites especially N.Q’s famous and majestic Mt. Mulligan. Dimbulah offers the visitor a delight of options and scenic adventures, a true blue outback experience. Growing up in North Queensland since 1969 I have forever dreamed of a 100 acres on a river in some quiet little spot.  Over 20 years I have worked towards that dream and looked far and wide for that place within a 150km radius from Cairns, this being of top priority as my business, The Pottery Place would have to undergo a major restructuring process in order to move it from Cairns.  I had purchased the 34 year old local business, The Pottery Place in late 2001 after studying Pottery at James Cook University and TAFE Ceramics in Cairns. The Pottery Place had seen better days, as have many of the Country’s Pottery Suppliers however I gave it my best shot.  After struggling with high rents and unfavourable demographics for the most part, it seemed the perfectly reasonable time to change my direction when my dream came true in September 2004.  Out of the blue, one lucky day, my Mother saw some pictures of the most perfect Home and Artists 4 Bay Work Studio on 100 acres on The Walsh River, for sale in Dimbulah!  Strangely enough I had never looked in Dimbulah but it was love at first sight. In May 2006 I moved into Dimbulah with The Pottery Place fitting into the shed as if it were purpose built. Since moving here it has been an interesting and successful restructuring process as I maintain a weekly delivery service to Cairns and have taken on teaching in Schools and Communities. I am now free to travel around being no longer constrained by the “Mon-Fri-9-5”. Teaching in Schools is rewarding and successful, the students, especially in remote areas are hungry for the art experience and I have not seen a child yet who does not love clay. I have also just hosted a fabulous weekend workshop with the wonderful Sallie Portnoy who came for three days to teach a Kiln Cast Glass Workshop. 10 Ladies from all over regional North Queensland came up to Longwater Camp for an exciting weekend with myself and Sallie. Under Sallie’s expert tutoring we all made exquisite glass pieces in just two days using my regular Pelectric Tetlow Pottery Kilns !.  The excitement and the freedom of being able to create pieces so instantaneously had everyone in awe and we are thrilled to be able to extend our pottery skills and use equipment that most of us already have in place, to venture into the world of glass. Sallie’s next Glass workshop is planned for September with bookings coming in now.  The spacious workshop at Longwater Camp is fully equipped with wheels, kilns, supplies, tools and equipment and offers the most incredible working spaces, situated high on a hill with amazing and inspirational 360° views of the surrounding country forever.  A visit to the river for lunch offers delightful surprises with tall trees, white sand, wallabies and birdlife galore all around the mighty Walsh River, running through all year long.  The night skies are clear and bejewelled with planets and stars and the simple exercise of building a little fire to cosy up to seems to have the ability of reawakening all of your senses.  I have never experienced in my life a place that oozes such incredible ambience, peace, inspiration and the awesome feeling of spaciousness and freedom, such a rare and treasured tranquillity in today’s frantic and busy world.  I invite all to visit, create, enjoy and experience this special little treat in our magical big sky country.

Cones measure the amount of heat absorbed. As the cone nears its maturing range, it softens and the tip begins to bend, drawn down by the influence of gravity or the weight of the sensing rod for cones or bars used in the Kiln-Sitter¨. It typically takes about 20 minutes for the cone to bend fully. Each higher cone number requires more heat to bend. Faster heating rates require the cone to be heated to a higher temperature.
Cone diagram

Pyrometeric cones are designed to mature (bend) at precise moments during the firing, by either shutting the kiln off at the proper point (as in the case of the Kiln Sitter and sitter cones) or used to simply indicate that a certain point was reached, as in the case of the witness cones. The exact moment the cone matures depends primarily upon two factors: time and temperature. The temperature present at the moment “cone” is achieved depends upon the rate of temperature increase. With this simple concept in mind it’s easy to understand why “cone” and temperature are not the same thing. For a proper cone firing, time and temperature must always be considered.

Large and Self-supporting cones are used as witness cones to monitor the firing and often are used to decide when the firing is complete.Use Self-Supporting or Large Cones whenever possible. Self-supporting Cones give the most consistent, repeatable performance due to the fixed mounting height and angle.

Small cones and Pyrometric bars are used in a Kiln-Sitter, a mechanical switch that cuts off power in electric kilns. Small cones are occasionally used as witness cones, but caution is recommended, since these shorter cones require slightly higher temperatures to bend, as compared with Large or Self-supporting cones.

Cones are still needed when a kiln is equipped with an electronic controller. Electronic controllers allow the kiln to be heated to a temperature. Controllers use a thermocouple to sense temperature. These change with time, causing the kiln to fire hotter than desired. Witness cones will check whether the controller is firing accurately.

Heating rate is important in the cone selection process. The temperatures shown in the temperature equivalent chart for each cone number are based upon specific heating rates. For faster heating rates, the cone must be heated to higher temperatures before it will bend.

Height of the firing chamber or the space available in the furnace can also be a factor in deciding which cone to use.

Consider the temperature range. While cones deform through a combination of time and temperature, the expected temperature range can determine the cone number and even the type of cone to use. For very high temperatures, a Large Cone or a PCE Cone may be needed. Self-supporting Cones are available for all low or moderate temperature use. Only small cones or bars should be used in the Kiln Sitter

Cone No.

Fahrenheit

Centigrade

Visual Color

022

DULL RED

021

020

019

018

017

016

015

014

013

012

CHERRY RED

011

010

09

08

07

ORANGE

06

05

03 1/2

03

02

01

1

YELLOW

2

3

4

5

6

7

8

9

10

WHITE

11

12

13

You have to always remember that the numbers with a

0

in front of them are not as hot as the numbers without.
When I first started working with ceramics, without thinking I just figured that

01

and

1

were the same.
It is very important to know what type of clay you are using so that the right Cone is used.
Using the wrong Cone can prove disastrous and expensive for a whole kiln load of ceramics or pottery, and even destroy your kiln.