May Luk on sun 4 jan 04
Hi all;
I aim to fire at cone 6 or 7. My firing ramp is 100C to 600C, 150C to 1238
and soak for 28 mins. I put cones in next to new glazes that I test. I just
found out I've been firing way over my target-cone 9 totally on the floor.
The last firing I did. I put in ramp: 100C to 600C, 150C to 1200 and soak
for 8 mins. The cone 9 is still doing a yoga childs pose.
My kiln is not very big-79 litre. still it's not very productive tweaking
the load just by fussing with the number settings.
It never really is a problem for the most part. For the year 2004, I'd like
to do more glaze test and wanting to pay attention to the heat work. I never
learnt how to fire manually though I know the concept. I was thinking I
would programme the kiln so that I would be there on the last few hours of
firing to make some manual adjustment. If I put in 3 cones [Orton 7-8-9] At
what point do I intervene? How to go about with a computer controller?
With this set of elements, I had done 21 bisque firing [1000C] and 28 glaze
firing. My kiln is 8 years old. I wonder if this has anything to do with the
discrepancy.
Many thanks in advance
May
London, UK
william schran on sun 4 jan 04
May wrote:>I aim to fire at cone 6 or 7... I was thinking I would
programme the kiln so that I would be there on the last few hours of
firing to make some manual adjustment. If I put in 3 cones [Orton
7-8-9] At what point do I intervene?<
If you want to fire to Orton cone 6, then a cone pack of Orton cones
5, 6, 7 is proper, when cone 6 bends until the tip is bent over to
the level of its base, you've reached the top temp and you can shut
off the kiln or better yet, allow a slow cool down.
After you see what temperature reading you get, you can program the
controller for other firings. I'd still recommend using witness cones
for both bisque & glaze firings.
Bill
John Hesselberth on sun 4 jan 04
On Sunday, January 4, 2004, at 06:37 AM, May Luk wrote:
> I was thinking I
> would programme the kiln so that I would be there on the last few
> hours of
> firing to make some manual adjustment. If I put in 3 cones [Orton
> 7-8-9] At
> what point do I intervene? How to go about with a computer controller?
Hi May,
Do you have a controller made by either Orton or Bartlett? They make
virtually all the controllers on this side of the pond, but I don't
know about your side. If you do have one of those, you can enter and
save half a dozen different firing programs--one primary and several
for standby or quick-switching purposes or bisqueing--whatever. Here
is what I would do and it will work pretty well for anyone who is
trying to get to know their controller and get it optimally programmed.
Let's say you want to fire to cone 6 with a 15 minute soak. Using your
current firing program, watch your cones and when cone 6 is about at 2
or 3 o'clock, note the temperature reading and shut the kiln off.
Quickly program a new cycle which has that temperature as the end point
of the first ramp and add a 15 minute soak. Then use whatever other
ramps you need to control your cooling as you desire.
Then restart your kiln. Learn to program it fast enough that your kiln
is not off more than 2 or 3 minutes before you start all this--this is
not the time to be reading the manual. It will have dropped a few
degrees in that time but will quickly come back up to what is now your
new peak temperature and start your soak. More than likely by the end
of the soak your cone 6 will be down to almost tip touching.
When it is all over reprogram your primary firing program based on what
you learned. It shouldn't take more than a couple times watching it
very closely and being prepared to reprogram quickly before the kiln
will do just about what you want it to on its own.
Regards,
John
http://www.frogpondpottery.com
http://www.masteringglazes.com
Ron Roy on sun 4 jan 04
Hi May,
You are getting good advice on this.
Pyrometers all read differently because of the way they are made - they are
not calibrated. This means you have to do it and adjust your controller to
shut off or start soaking at the right time by matching the temperature
your thermocouple is reading with the cone you are firing to.
You must program a typical firing and watch the cones - when they begin to
fall you have a good indication were to set your end temperature on the
controller. You will need to do custom programs to do this of course - not
a big deal but some manuals are not easy to follow - just keep trying and
asking questions.
Some controllers have a "skip step" feature - you can skip to the next step
- say from when the cones start to fall to the soak. Handy when you are
trying to find the right top temperature setting.
I have lost that post but did you say you are coming to NY for a couple of
months?
I'm not that far - about 400 miles - a one day drive - John is even closer
- near Philadelphia - about an hour from NY.
If you would like to spend a few days studying with me we could make plans
- We have a guest room - all it would cost is $50 per day and some food
sharing?
I will send this to John - although he will be busy house building so I
don't think he will have much spare time - it would be a big help if you
could spend some time with either of us.
Anyway - something to think about - we should take opportunities when we can.
Best for now - RR
>I aim to fire at cone 6 or 7. My firing ramp is 100C to 600C, 150C to 1238
>and soak for 28 mins. I put cones in next to new glazes that I test. I just
>found out I've been firing way over my target-cone 9 totally on the floor.
>The last firing I did. I put in ramp: 100C to 600C, 150C to 1200 and soak
>for 8 mins. The cone 9 is still doing a yoga childs pose.
>
>My kiln is not very big-79 litre. still it's not very productive tweaking
>the load just by fussing with the number settings.
>
>It never really is a problem for the most part. For the year 2004, I'd like
>to do more glaze test and wanting to pay attention to the heat work. I never
>learnt how to fire manually though I know the concept. I was thinking I
>would programme the kiln so that I would be there on the last few hours of
>firing to make some manual adjustment. If I put in 3 cones [Orton 7-8-9] At
>what point do I intervene? How to go about with a computer controller?
>
>With this set of elements, I had done 21 bisque firing [1000C] and 28 glaze
>firing. My kiln is 8 years old. I wonder if this has anything to do with the
>discrepancy.
>
>Many thanks in advance
>
>May
>London, UK
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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