[maplesyrup]

Hi,
A very basic bisque question: I've had the kiln warming overnight (bottom element on low) and the lid on. I know that I should crack the lid to let the moisture escape during the beginning of the firing, but will I shock the pots if I do that now? Should I have kept the lid cracked overnight?

In other words, can I now safely turn the other elements to low AND crack the lid? And when is the best time to close the lid?

thanks for any help

[bciskepottery]

If you had a vent on while candling overnight, you are fine. If not, then it would have been better to have left the plugs out or cracked the lid while you were candling so any steam might have escaped. Cracking the lid now (assuming you have no vent), before firing up the other elements, should not be a problem. It will allow the burnt out organics to escape. Close around 1000F. If you have a vent, there is no need to crack the lid.

[maplesyrup]

thanks!

[neilestrick]

Assuming you do not have a downdraft vent attached to the kiln, as long as you leave the top peep open there is no need to prop the lid. If you do have a vent, all peeps should be left in during the entire firing.

[OffCenter]

maplesyrup, on 18 April 2013 - 07:57 AM, said:

Hi,
A very basic bisque question: I've had the kiln warming overnight (bottom element on low) and the lid on. I know that I should crack the lid to let the moisture escape during the beginning of the firing, but will I shock the pots if I do that now? Should I have kept the lid cracked overnight?

In other words, can I now safely turn the other elements to low AND crack the lid? And when is the best time to close the lid?

thanks for any help

Were the pots completely dry when you loaded the kiln. If they were, you're wasting a lot of time and energy. For dry pots of normal thickness just load the kiln and fire on low until 250 then turn on high.

Jim

[Chris Campbell]

I agree with Jim ... Why are you candling overnight?
Unless your pots are wet you can just start firing.
Sometimes in a teaching or school setting loads are pushed due to time constraints and loads are unevenly dry ... so they candle a few hours for caution.
But at home, with dry pots, just shut the lid, close the peeps and fire the load.

[gypsy]

Chris Campbell, on 18 April 2013 - 11:12 AM, said:

I agree with Jim ... Why are you candling overnight?
Unless your pots are wet you can just start firing.
Sometimes in a teaching or school setting loads are pushed due to time constraints and loads are unevenly dry ... so they candle a few hours for caution.
But at home, with dry pots, just shut the lid, close the peeps and fire the load.

I didn't know you didn't have to candle a bisque....thanks for the info.

[Pompots]

gypsy, on 18 April 2013 - 10:06 AM, said:

Chris Campbell, on 18 April 2013 - 11:12 AM, said:

I agree with Jim ... Why are you candling overnight?
Unless your pots are wet you can just start firing.
Sometimes in a teaching or school setting loads are pushed due to time constraints and loads are unevenly dry ... so they candle a few hours for caution.
But at home, with dry pots, just shut the lid, close the peeps and fire the load.

I didn't know you didn't have to candle a bisque....thanks for the info.

No, Candling is only when you are not sure if the pieces are not dry enough, then you candle, if your pots are totally dry, as someone said already its just a waste of energy and time.

[Frederik-W]

OffCenter, on 19 April 2013 - 02:44 AM, said:

Were the pots completely dry when you loaded the kiln. If they were, you're wasting a lot of time and energy.

Jim

I also agree with Jim. If your pots are completely dry, do not waste energy.
However if you have very thick things it will need more pre-heating.