Expert: Sam Kelly - 4/25/2009

Question
I have a new small geil kiln, dlb-8.  I am getting about 51/2 inches of wc
pressure but according to the firing schedule geil supplies I need over 6 to
complete the cone 10 firing on schedule.  however, it says on the kiln that
3.5 is the maximum gas pressure and I know other people who follow a
different schedule and never run the gas over 3.5.  if I follow geil's sched it
takes me about 2 hours complete the last hundred degrees to cone ten.    but
the people i know,  who soak their kiln at 1562 degrees have no trouble
getting up to cone ten with 3.5 wc pressure.  all this is confusing me.  how
much pressure do I need?    should i try a different firing schedule.  i think I'm
also losing reduction because if i shut the damper down farther the temp
rises even slower.
thanks for your help.
sincerely,
sean de queiroz

Answer
Hi sean, I think you may have answered your own question. Are you creating to much reduction. talk to the others and see where the air wheel on their burners are situated.

on both my gas kilns the wheels are fully open and all reduction is handled at the damper.

how do you measure the amount of reduction being applied