Talbott on mon 10 mar 97
Over the last couple of months I have noticed that our 40 cubic ft,
propane fired kiln has been taking longer and longer and longer to fire.
The burners during the firing looked and sounded the same as before. I
thought that since the kiln was about 3 years old that the insulating
ability was diminishing for some unknown reason to me. Perhaps the really
cold ambient air was the problem. I had to push the damper in further and
further each time to go into reduction on the glaze fire at around 900
Celsius. Yesterday morning I started the kiln up for a glaze fire and all
seemed fine. Got to 900 C and wanted to start reducing at about .5 to .6
on the oxy probe. So I pushed the damper in and nothing... Still in
oxidation...(oxy probe at .05) So I turned the burners up to 7 psi, I
seldom go above 4 psi... nothing..., still in oxidation. What could be
going on??? Would we lose this glaze fire. Then a clue...
I heard a sputtering in one of the two burners! So I shut that
burner down... and put the burner port bricks up ... 5 minutes later I
removed the orifice nut and there was the villian... carbon build-up in the
3 orifices each one 1/16" in diameter. I cleaned the orifices up and shut
the other burner down and cleaned that one up as well. (Damper in and
burner port bricks in place during the shut down) Only lost about 15 min.
and restarted both burners. All of a sudden I am in reduction (oxy probe
at .7) at 2.75 psi with the damper all the way OUT! What a relief... All
of a sudden it is like a brand new kiln. Flames from reduction licking out
from the spaces between the door and the arch. Just like the good old
days... Man.. what a relief to be back in the groove again.... So I
stayed around .68-.71 on the oxy probe until ^9 was flat. I will open the
kiln on Wed... can't wait to see... Christmas in March.
Lesson learned... Keep those orifices clean.. I will now do so before EVERY
firing- glaze or bisque... P.M.S. Preventive Maintenance System on
those burners will go into affect. ALSO always make sure you have a couple
of extra thermocouples around in case one or more go down and you are at
cone 7 going to cone 10... Happened to me once and luckily I had one on
hand...
Check out the 1st Annual Clayarters' Gallery web-page at:
http://fmc.utm.edu/~dmcbeth/cag/naples.htm It can be viewed but is
still under construction... Thank You.. David McBeth
Best Wishes... Marshall
1ST ANNUAL CLAYARTERS' GALLERY - NAPLES, MAINE (Summmer 1997)
http://fmc.utm.edu/~dmcbeth/cag/naples.htm
>the above site can be viewed but is still under construction<
below are other web-sites which mention the exhibit:
http://www.missouri.edu/~muck/
{contact me directly for more information}
Celia & Marshall Talbott
Pottery By Celia
Route 114
P.O. Box 4116
Naples, Maine 04055-4116
(207)693-6100 voice and fax
clupus@ime.net
Clayarters Live Chat-Room 10:00 pm Eastern Standard Time on Saturday Nites
SHORT CUT if the room has already been created then go to:
http://webchat9.wbs.net/webchat3.so?Room=PRIVATE_Clayarters
or if room has not been created go to WBS at:
http://webchat5.wbs.net/webchat3.so
and set up a "Private Room"... just use the name: Clayarters
------------------------------------------------------------------------------
| |
|
