Cone melted to metal setter arm

[LAR]

Hi everyone,

I used the kiln I was gifted for the first time yesterday, and had some good success and some challenges.   The first challenge was that the cone setter dropped and turned off kiln about 6 hours in.  I manually restarted careful not to trip setter, and added about an hour to the cycle.  Then I called a local expert, and she had the good sense to advise that I turn the firing off.  This morning, my results on white clay were a light golden color (which is to my first-timer liking).   Nothing had broken, but . . . . . the cone had melted to the setter armature.    I'd like to monitor my temperature next time, and also remove the melted cone.   Thankfully, I was able to easily remove the stationary peg arms.   Advise?     

[Min]

Hi and welcome to the forum and congrats on your kiln.

The shut off timer is a backup safety device, the sitter with the small cone (or bar) is the primary device to shut off the kiln. If after firing your kiln a few times you know it takes 9 hours then the timer could be set to 10 hours to shut the kiln off in the event the sitter doesn't trip. It often does take several firings to get a kiln firing the way you want it to. I would suggest putting some witness cones on the shelves so you can see how it is actually firing. I don't know what cone you are firing to but for an example if your target is cone 6 then a cone pack with cones 5,6 and 7 would be used, this way you can see if your kiln is under or overfiring or just right.

There is a little firing gauge you can get to calibrate your sitter. Also, I would put kiln wash on the 2 cone supports (but not on the sensing rod that rests on the cone).

Edited April 11 by Min

[neilestrick]

If the weight dropped and turned off the kiln, then it reached the proper cone at that point regardless of how long the firing took. When you restarted it, it fired beyond that cone and melted the cone. Depending on how badly the cone melted to the arms, you may be able to clean up the cone support arms with a Dremel, but if not you'll need to replace them.

[Hulk]

"I'd like to monitor my temperature next time..."

I'd used a portable pyrometer to monitor my first kiln (fully manual); at the time, this TPI dual input unit (sold by Skutt, and others...) was on sale.

Using it, I was able to keep firing notes that included times, temperatures, observations, results, et cetera.
The notes can be handy. Over time, monitoring element decay, for example; how much longer a firing takes with two more shelves and the posts - mass matters! - and how much longer it takes to cool to opening; reference for programming ramps and holds for the new kiln, priceless? Maybe not, but useful? Yep!

The new kiln has three thermocouples. I've been using the portable as well, however, to get an idea how the readings compare.
Now that I've completed a few firings, the portable may be regulated to backup...

 

 

[LAR]

Thank you so much, new friends in this (new to me) community.  I appreciate so much your help and time, and expertise.  In reading various posts yesterday, I learned that cones are basically glaze (glass), so I gently broke off the melted cone.   I'm wiser than yesterday, thanks to my mistakes and all of your shared knowledge.  Next step for me is glazing.   If you don't mind, I'll check in with y'all as I learn.

Again,

thanks for explaining and advising me regarding what happened, and ways to improve my outcomes.

This is a fun adventure for me.   Here's my first haul.   Beads, glazed beads firing rack, wall art slabs, (maybe to be used as stamps on canvas too), glazed pendant firing hangers, and sculptures by grandkids, etc.  Fingers crossed.

LAR in CA 

[Pres]

Welcome to the forum! You may do searches using the search tools in each strand area, or you may do a search in the main screen to search all areas for a specific question/subject.

Hope you get all the help you need to grow into producing for yourself and your grandchildren.

 

best,

Pres