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Witness cones question

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So I ran my first Cone 04 bisque load in my new-to-me Sandstone Skutt manual ~6 cf kiln. It stated in the manual to run at test run, so I threw in what greenware I had and  placed all three shelves in  the kiln (staggered). Witness cones were place bottom, middle and top (in the middle of the kiln).  At the top I got to Cone 05, not really at cone 05 in the middle, and not at all at the bottom. Although older, the kiln is in immaculate shape. So question - does this mean I would need to place a Cone 03 in the kiln sitter to see if I can get my witness cones to a cone 04? Or is it possible that my elements need replacing even though it looks brand new? Thanks!

Edited to add that I followed the manual - all three switches on low for 1 hour (lid and 3 peepholes open). All three switches to medium for two hours (lid shut and one peep hole open) then all three switches to high (lid shut and all peepholes shut) until shutdown. It ran for 4 hours in total. 

Edited by Cajonat
added some more info
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13 hours ago, ronfire said:

I will fine tune the sitter with a feeler gauge between the claw and drop weight. I find a .006 works most of the time, .004 will fire a little hot. Amazing what .002  clearance setting makes.




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The "official" calibration instructions specify that with the calibration disk installed inside, the inner edge of the claw should be 1/16" from the outer face of the drop weight plate, and the plate should barely clear the claw as it swings down. My easy method for adjusting to those specs is 1) raise the drop weight plate well into the claw so it can't drop. 2) Use a common 1/16" twist drill bit as a feeler gauge and adjust the claw in or out as needed until the drill bit slips out but doesn't wiggle in between the plate and claw. 3) Tighten the claw, and loosen the plate to slide it down until it just clears the corner of the claw. Tighten it. 4) Done. I keep a little zip baggy taped to the inside cover of my manual containing the calibration disk, the drill bit, and both sizes of  miniature allen wrenches needed for the job.

Edited by Dick White
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