Hopie Lopez-Boyett on tue 5 oct 04
I just got a used Blue Diamond. It seems the kiln fires very very quickly
and I wanted to know what i might be doing wrong. I have been told that
for bisque it should take 10-12 hours and for glazed 8-10...it has taken
much less then that (7 hours to bisque) and i have gotten some strange
results with the cones. In both firings the kiln sitter cone is perfect -
really looks to be spot on. BUT the cones on the lower shelf seem to be
underfired while the cones on the upper shelf seem to be overfired. I
tried moving the cones from the edge of the kiln to the center to see if
that would make a difference but it did not.
I found a schedule on the web which show how long to keep the switches on
low, med & high and that is what i followed. The only other schedule i
found suggested to stagger the lower and upper sections such as off on the
top and low on the bottom at first then to med etc.... but this is all a
shot in the dark since i really dont know what iam doing.
Any suggestions would be helpful!!!
Cynthia Bracker on tue 5 oct 04
Hopie Lopez-Boyett wrote:
>I just got a used Blue Diamond. It seems the kiln fires very very quickly
>and I wanted to know what i might be doing wrong. I have been told that
>for bisque it should take 10-12 hours and for glazed 8-10...it has taken
>much less then that (7 hours to bisque) and i have gotten some strange
>results with the cones.
>
What schedule are you following that is yielding a 7 hour bisque?
> In both firings the kiln sitter cone is perfect -
>really looks to be spot on. BUT the cones on the lower shelf seem to be
>underfired while the cones on the upper shelf seem to be overfired.
>
You might need to do a kiln sitter adjustment, or change your bottom
elements or both. You should ALWAYS check your kiln sitter after moving
a kiln - even just moving from one room to another within the same location.
>I found a schedule on the web which show how long to keep the switches on
>low, med & high and that is what i followed.
>
What did that say schedule say and what result did you get? You can
also look at a firing schedule on our website,
http://www.brackers.com/tech_corner/firing_with.cfm (if you have a
downdraft vent on your kiln) or
http://www.brackers.com/tech_corner/firing_without.cfm (if you don't)
keep in mind that this and all firing schedules you will probably find
online are a starting poing and may need some adjustment based on size
of kiln, condition or elements, condition of kiln etc.
>The only other schedule i
>found suggested to stagger the lower and upper sections such as off on the
>top and low on the bottom at first then to med etc.... but this is all a
>shot in the dark since i really dont know what iam doing.
>
Before doing that, I would buy a pyrometer and see what the temperature
in the kiln is doing during the firing. Then if you notice that the
bottom of the kiln is lagging 2 hours behind the middle and top, you can
turn just that switch up until it catches up etc.
Good luck!
Cindy Bracker
Bracker's Good Earth Clays, Inc.
Cat Jarosz on tue 5 oct 04
Dear Hopeweaver,
the easiest thing to do is BE THERE for the last part of the firing...
With my old L and L kiln I never had to turn the top ring on high , med/high or
number 8 on a 12 numbered dial. I had the J245 which has 5 rings too so
seems to me that the bottom 2 rings would be on high and the rest would be
lower depending on how tight I packed the kiln... everything varies so
knowing your kiln is VIP...
I have a brand new L and L that I just broke in this past month and its
been a joy.This one is 4 rings and 29" wide inside!.. So far not much time
difference between the top and bottom rings firing out on high. so what I do
is put a clay wad or piece of paper or crud in the kiln sitter arm when it
decides to shut off just to keep it going. Shut the rings off that have
reached temp and wait till the other rings reach temp and shut them off one by
one as they get there....
Cat J in sunny mountains of Western NC , I survived the hurricanes with
minimal damage and losses and the area is recovering faster than expected woo
hooo spin on head.. ( the blue ridge parkway WILL BE OPEN in time for
tourist leaf peeper season) What a great country we live in !!!!
V)''(V woof & >^..^< mew, Chicks with beards rule !!!
(_o_)
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