Advice On Cone 06 Firing, Brand New Olympic Kiln

[Jeepersca]

I am new to this forum.  I'm a little intimidated because I am not currently throwing my own pottery, but work with bisque and detailed glazing, and I am also using commercial glazes (Duncan).  I am probably more of painter than a potter, by discipline.  Hopefully I'm not too out of place here.

 

I recently purchased an Olympic electric kiln.  I have only fired it once so far, and wanted to ask advice about my results... I have never managed my own kiln, only working in studios where that part is taken care of by the studio. 

 

I filled the kiln with all of the furniture that I had to take up space (and all of my newly kiln-washed shelves) but only one actual tester piece.  I know it's not ideal to fire it empty, but I didn't want to put too much in there in case I ruined everything.  It was a small bud vase that I did a simple doodle on, and then covered in a clear glaze.  In all honesty, the manual for my kiln had Ramp-Hold features which I have no clue when one might use them... I imagine for more complicated glazes, perhaps one with pigments that fire off at different temps, I'm not sure.  I went with simple,, manufacterer recommendations say to fire to cone 06.  My kiln gave me the option of holding at temp... so i input a 10 minute hold, not knowing if that was the right thing to do or not.

 

I used 2 Cone 06 temperature cones to monitor the kiln, and this was my result:

 

Cone on the top of the kiln, visible through the peep hole, started to bend first.  It was nearly all the way to "3 o'clock" by the time the second cone, located near the bottom of the kiln, started to lean. The kiln reached 1829F and then held for 10 minutes as programmed.  Once the kiln had cooled, I saw that the top cone had arced over too far, the nose of it coiling a little onto the kiln shelf, the rest of it drooping.  The bottom cone was also over too far, but not quite as bad.  The tester piece - the clear glaze was perfect, but I noticed the doodle I did on it bled a little bit.

 

I suspect one or both of these are true:  I did not need to program in a 10 minute hold at max temp, that holding for the extra time caused my detail glaze to bleed.  Second, it's possible that just programming in "fire to cone 06," though pre-programmed, was too hot and caused my glaze detail to bleed.  Based on the 2 cones I had in the kiln, I know for certain that they were over fired... I'm just not sure which way to jump to fix my issue.

 

I am under the impression that the glazes I have are close to idiot proof, as in 'fire to temp' and it should all go well... will removing that 10 minutes fix this issue?  Or should I possibly fire to cone 07 instead because my kiln is perhaps a little hot?

 

Picture of my tester problem - bleeding lines:

https://scontent-a-sjc.xx.fbcdn.net/hphotos-prn2/q83/s720x720/1186184_326536344159869_1472765374_n.jpg

 

Examples of other work that I do, and plan to fire in my own kiln (they range from traditional to absurd):

http://imgur.com/a/DNWky#0

 

I am loading a new kiln later today, with two testers in it, but I wanted input on how to change how I did it so that I mimize bleed.

[Diane Puckett]

Cone level reached is a combo of temperature and time. Adding a hold increases time so increases the cone. If you are testing to see if your kiln reaches 06, you need to fire with no hold. If I were you I would repeat what you did but without the hold. Also, talk with the person who fires the kiln you work had been fired in to find out exactly what they do. Making sure your kiln is calibrated may be a separate issue from your glaze bleeding.

 

I don't use the Duncan glazes you are using so cannot help with that. The manufacturer might be able to give you some guidance.

 

Your work is beautiful!

[Karen B]

You will not need the ramp-hold feature. I use it to do a slow cool-down to enhance crystallization of glazes from cone 6.

Really nice work!

[oldlady]

there is another member who has recently worked out her new olympic kiln fears.  check out the profile for pugaboo and read what she has said.

[Jeepersca]

there is another member who has recently worked out her new olympic kiln fears.  check out the profile for pugaboo and read what she has said.

Will do, thanks very much!