another kiln shelf question

[fergusonjeff]

I am currently mostly firing a wood kiln and use 12x24" silicon carbide shelves that have held up well through about 30 firings.  I am planning to build a gas (cone 10) kiln that will use the same size shelves.  I would like to start buying 12x24 advancers, but at almost $300 each that is too much at one time. I plan to fire lots of flat plates and flat shelves are critical. 

I know there was some discussion of the nitrile bonded shelves with the cuts, but I don't remember if they are reasonable substitutes for advancers.  Here is a link to some that are only $100 per shelf. 

https://nmclay.com/lgrf330-shelf-sil-carb-nitride-bonded12x24x-394

Any thoughts?

Thanks,

Jeff

 

[neilestrick]

I don't know if they have improved over the years, but I bought a few of those back in 2004 and they didn't last long at all in my gas kiln. They warped pretty quickly, and continued to warp in my electric kiln at cone 6.

[fergusonjeff]

Thanks Neil.  That is what I was afraid of.  I have been really happy with my 26" half round advancers at cone 6 electric.  Just hoping there was a better solution than $5000 all at once.

[Mark C.]

I have bought 4 over time and they all warped-I would not waste $ on them myself 

The next best shelve I have used at cone 10 and above is a dry pressed high alumina english  shelve -they are 1 inch thick and weigh 33#s each and hold up well -they can warp over a long period of firing-I fired them for 15+ years at 30 fires a year with minimal warping in my reduction kiln-they are great in salt or wood kilns as well. I had mine trucked in from Tacoma Clay in Wa state

As I got older and adavancers came to light I retired them. I also saved about 25 inches of stack space in kiln every fire.

[Piedmont Pottery]

I've been using the nitride bonded SiC 12x24 shelves for a few years, but only at cone 6 oxidation.  I've had no issues with them, but I'm not doing cone 10 reduction either.  The one's I am using were from Axner.  They claim on their website that they are "rated for temperatures much higher than regular silicon carbide shelves".  Shipping and handling were expensive, but that's true of any kiln shelves.