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Don't do it! Use a kiln shelf. The shelves are easier to replace or repair if you have some sort of problem with your glaze running. Steve in Tampa, Florida, USA

Also the floor of a kiln is MUCH cooler than the kiln temp, and you will seriously underfire the glazed pieces on the floor. This also applies to bisque firing, although you mightn't notice it until the piece cracks later due to stresses in the base.

Dave

Absolutely! Having tried that once, and destroyed the bottom of a kiln (one with bottom elements to boot), i would say a shelf is much cheaper than a repair.

Wayne in Key West (Oh, to be young and stupid again......NOT!)

The floor shelf in a kiln needs to be only 1/2" to 1" off the floor to allow heat to circulate under it. The small loss in space would be far better than having to refire all the pieces on the floor because the bottoms were underfired, or having to replace floor bricks because some glaze ran off and lifted a great chunk of brick out. Glaze actually dissolves (fluxes) refractory insulating brick so a small amount will leave a large crater. Its not worth it.

Dave

Save yourself some heartache. Place your bottom shelf on 1/2" stilts and leave it.

If you only need 1/2" stilt on the bottom I will try it out. Thanks

you don't need much height. resting a shelf on the kiln floor is a classic "conduction" situation for heat transfer - the fastest method of heat transfer drawing heat away from the lower shelf. having the shelf up a small amount changes the situation to no longer conduction but radiation - the slowest form of heat transfer, heat loss.

think of your floor as a giant ice cube (on the scale of heat going on). is THAT where you want to fire your pots?

meanwhile when i do unglazed pieces i usually rest them on the floor and between burners to save shelf space for other stuff.

see ya

steve

steve graber