New Kiln Shelves/ Shelf Paper

[Wind n Wing]

I have an old Duncan Kiln that has seen many good years of service.  I have had it for 20 of those years  I bought it used and have recently replaced the elements in it.  The shelves are original and  are warping  I usually fire to  cone 04 for the first firing and then to a cone 6 for the final fire.  It is an  15" octagon shelf that is being used. The shelves are 1/2" thick and are a yellowish color.  Would appreciate any suggestions as to type and thickness I should be looking at.

 

Don't do a lot of Glaze firing, but some and would like to do more. I recently saw an ad for shelf paper.  and am not familiar with this product.

Common sense tells me it is a liner to keep you shelves clean from glaze drips and runs.  Do you replace it every firing or does it burn out in the firing, If you are familiar with shelf paper what are its pros and cons.  Do you need to Kiln wash your shelves prior to using it or can you leave them bare.

 

Thanks in advance for any help.

 

RJ

[bciskepottery]

Shelf paper is generally used in glass kilns that fire to lower temperatures than a clay kiln.

 

Lots of pros/cons to putting kiln wash on shelves. Most do to protect against glaze runs. Even if you are careful and know your glazes, you can hit the glitch where the kiln overfires, the glaze application was thicker than planned, etc., resulting in a glaze mess on the shelf.

[Roberta12]

I use shelf paper for slumping bottles.  I think the temp rating only goes to 1500 degrees.  Not enough for what you want.  Some shelf paper burns out each time and more expensive stuff can be used a number of times, with care. 

 

The community studio I started in had issues with kiln wash.  Left me with a bad memory.  When I got my own kiln, I did not kiln wash my shelves, but I do put cookies (kiln washed) under each piece.  Maybe it's more work, but it's what I do.  However, I have since learned there is a proper way to kiln wash shelves.  So if I were starting out with new shelves, I might wash them.  Seems to be a personal choice.

 

Roberta

[neilestrick]

I'm a big fan of Corelite shelves. They are super lightweight and don't warp.

[Min]

Ummm, hate to say it but my 20" square Corlites are warping. Had them just under 3 years, firing to ^6 about 1 1/2 times a week.

[neilestrick]

Ummm, hate to say it but my 20" square Corlites are warping. Had them just under 3 years, firing to ^6 about 1 1/2 times a week.

 

Interesting. I've got a few hundred firings on my 14x28" Corelites and they're as flat as the day I bought them. One of the folks at Lillstreet said the've fired theirs to cone 10 for a few years without flipping them and they're still flat. Another friend puts his in the wood kiln. Think it has something to do with the square shape? Poor quality control?

[perkolator]

I would suggest simple 1" thick cordierite shelves.  Almost twice the thickness of regular 5/8" thick shelves, so shouldn't really warp on you at ^6 unless you're putting considerable of weight on it, in which case it'd likely crack first.

[Joseph Fireborn]

I have corelite shelves as well. Never flipped them. Over 178 firings so far no warping.