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kiln question -- slight twist

updated mon 30 jun 97

 

Mo Cain on thu 19 jun 97

This is a slight twist on the question at hand. I recently joined a
group of potters who are struggling with the mysteries of fire... more a
case of the blind leading the uninformed really. We have an old Olympic
that had a face plate indicating that it was set up for 240v and
apparently in the past never had performed well not even getting to
bisque temp (04) in less than than 12 hours and our workshop is only
open for 10 hours a day and of course the kiln is never left unattended.
We finally determined that the house wiring was 208! Our local kiln guru
came in and replaced the elements appropriately and off he went
muttering " well that's all right then". There has been little
improvement and although we can now bisque within our 10 hour window we
still can't get beyond cone1. The kiln man says everything is Ok but it
clearly isn't. When modifying from 240 to 208 are there other changes
that have to be made within the kiln controls?
Is there anyone out there in the Atlanta area who knows of a really
knowledgeable kiln technician..we would surely like to talk to him
(her?)
mocain in Atlanta where we need to be thinking about how long 40 cubits
is because it ain't 'alf rainin'.

Harvey Sadow on fri 20 jun 97

Yo Mo,

Olympic Kilns is in Atlanta! Bob Haugen and his family are just
terrific people and have always been incredibly helpful to me when I
have called. My guess is that they will know how to help. Their
address is:

Olympic Kilns
6301 Button Gwinnett Dr.
Doraville, GA 30340-1520
Phone: (770)441-5550 Fax: (770)446-3856


Mo Cain wrote:
>
> ----------------------------Original message----------------------------

> Is there anyone out there in the Atlanta area who knows of a really
> knowledgeable kiln technician..we would surely like to talk to him
> (her?)
> mocain in Atlanta where we need to be thinking about how long 40 cubits
> is because it ain't 'alf rainin'.

David Hewitt on sat 21 jun 97

I am not familiar with Olympic kilns but do have a Cromartie electric
top loader and have experienced the problems involved in a power supply
voltage change from 240 to 230. Having elements for the lower voltage,
i.e. shorter in length, made a big difference. I have a meter
permanently installed on the supply to the kiln so that I can see how
many Kw it is taking when on full load. Also, if I wish, I have a tong
tester so that I can make a spot measurement of the amps being supplied.
Multiply this by the nominal voltage to get the watts.
Does the face plate of your Olympic give a current or Kwh rating? Does
it also give a maximum temperature for which it was designed? Not all
electric kilns are designed for 1300 C operation.
My Cromartie is a CTL75. That means its volumetric capacity is 75
litres. Approx 18" diameter by 18" high working volume. It has a 5Kw
rating and will biscuit fire to 100 C in 6-7 hrs and to cone 8 in 8-9
hrs according to the contents and with good elements.
In message , Mo Cain writes
>----------------------------Original message----------------------------
>This is a slight twist on the question at hand. I recently joined a
>group of potters who are struggling with the mysteries of fire... more a
>case of the blind leading the uninformed really. We have an old Olympic
>that had a face plate indicating that it was set up for 240v and
>apparently in the past never had performed well not even getting to
>bisque temp (04) in less than than 12 hours and our workshop is only
>open for 10 hours a day and of course the kiln is never left unattended.
>We finally determined that the house wiring was 208! Our local kiln guru
>came in and replaced the elements appropriately and off he went
>muttering " well that's all right then". There has been little
>improvement and although we can now bisque within our 10 hour window we
>still can't get beyond cone1. The kiln man says everything is Ok but it
>clearly isn't. When modifying from 240 to 208 are there other changes
>that have to be made within the kiln controls?
>Is there anyone out there in the Atlanta area who knows of a really
>knowledgeable kiln technician..we would surely like to talk to him
>(her?)
>mocain in Atlanta where we need to be thinking about how long 40 cubits
>is because it ain't 'alf rainin'.
>

--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP6 1DQ, UK. Tel:- +44 (0) 1633 420647
URL http://www.ceramicsoftware.com/education/people/hewitt.htm

Fay & Ralph Loewenthal on mon 23 jun 97

Dear Mo, I do not know what kind of kiln technician you
have in Atlanta, but that kind of animal is a very rare
breed here. We have to do it all ourselves.
I have refurbished a few kilns, and have found when I
put in either too many elements or elements that are too
long I have the same problem. What is happening here is
the resistance is increasing and the amperage is
dropping. If I reduce the number of elements thereby
shortening the total length of wire I decrease resistance,
increase amperage and get the temperatures needed in
reasonable time. I hope this helps Ralph in PE SA