Can these be used for oven floor?

[david s]

Re: Can these be used for oven floor?

[COLOR="black"][COLOR="DarkRed"]We used 2 layers of 1 inch thick 14x16 in #2 pizza stones and the floor works great.

At $39 ea and a double layer, that"s a pretty expensive floor.
Doubt whether you'll be selling too many of those.

[david s]

Re: Can these be used for oven floor?

Sorry, my misreading, as the tiles are over 2" thick I doubt you'd be using them for kiln shelves.

[GianniFocaccia]

Re: Can these be used for oven floor?

Sure, but Gianni said Harbison Walker told him that the shelves were made of the same material as the fire bricks

Yes, the refractory 'tiles' were made of the same material as their firebricks, but I'm unaware if they are used for kiln shelves.

[david s]

Re: Can these be used for oven floor?

Hear, hear.

[shuboyje]

Re: Can these be used for oven floor?

Got ya now. I was responding to the original poster which I now see was a couple months old. Too bad this old thread was brought back to life by another shameless attempt to drive commerce to another site and away from forno bravo.

[david s]

Re: Can these be used for oven floor?

Density has nothing to do with conductivity. I'm talking about completely different materials here. Kiln shelves are generally made of Cordierite, which is much more thermally conductive then firebrick. Any I've ever seen that are Cordierite are an even more thermally conductive material.

Sure, but Gianni said Harbison Walker told him that the shelves were made of the same material as the fire bricks. My reference to density was assuming the materials were the same and therefore the only other variable would be the temp they were fired to which does affect density because the higher fired material will be denser because there is greater shrinkage.

[shuboyje]

Re: Can these be used for oven floor?

Density has nothing to do with conductivity. I'm talking about completely different materials here. Kiln shelves are generally made of Cordierite, which is much more thermally conductive then firebrick. Any I've ever seen that are Cordierite are an even more thermally conductive material.

[GianniFocaccia]

Re: Can these be used for oven floor?

If this is right and the shelves are fired to the same temp as the bricks, then they should be the same density

When I picked up my floor insulation from H-W I tried picking up one of these floor tiles. They looked exactly like the firebricks they had there except maybe a little smoother. They were proportionately heavy and my only thought was "I wish I could afford these"...

[david s]

Re: Can these be used for oven floor?

Kiln shelves are much more thermally conductive and could really throw the balance of the oven off, especially with the high dome of a standard Pompeii oven.

"Harbison Walker (ANH Refractories) has 24"x12"x2.15" refractory tiles which are made of the same material as their firebricks. A year ago these were $32 each at their location in Los Angeles. They have a location in Dallas."

If this is right and the shelves are fired to the same temp as the bricks, then they should be the same density.

[GianniFocaccia]

Re: Can these be used for oven floor?

We used 2 layers of 1 inch thick 14x16 in #2 pizza stones and the floor works great

From a quick look at your site, it says your double-layer of pizza stones sits directly on a layer of sand. How is this working for keeping your stones hot? Do they retain their heat for a long time?

[shuboyje]

Re: Can these be used for oven floor?

Kiln shelves are much more thermally conductive and could really throw the balance of the oven off, especially with the high dome of a standard Pompeii oven.

[david s]

Re: Can these be used for oven floor?

I'd say used tiles are a no-no; new ones, I don't know.

Pottery glazes are typically made of silica, alumina, a flux, and a colorant. The fluxes can contain metallic oxides which can be toxic. She may say that no "heavy metals" were used, but that only eliminates part of the periodic table. And then there's the colorants. You have no idea what their chemical composition is. Unless she knows the exact comoposition of the glaze, I wouldn't be enthusiastic about cooking on them.

It also seemed to me that the kiln shelves were very porous when I looked at them. I'd be interested to see how they work out, though. It could lead to a much lighter oven.

It is not only toxicity from the glaze that is the problem. There are a whole host of nasty chemicals produced from the clay body at biscuit firing temperatures including formaldehyde and sulphurous chemicals.How much would be in the shelves is anyones guess.


3.1 Hazards of firing
When clays and glazes are fired, they release various gases, vapours and fumes, which can adversely affect health if inhaled. The gases, vapours and fumes which may be emitted during firing include:
carbon monoxide
formaldehyde
sulphur oxides
halogens metal fumes
formed when carbon-containing compounds from the organic matter found in most clays and many glaze materials are burned in a limited oxygen atmosphere, such as electric kilns. Carbon monoxide is an asphyxiant
formaldehyde may be formed when organic materials decompose. It is an irritant of the eyes and upper respiratory tract, a sensitiser which may lead to asthmatic symptoms in some people and a suspected carcinogen. Its vapours may form explosive concentrations in air
sulphur-containing compounds are found in many clays and glaze ingredients. When these decompose with heat, they release sulphur oxides, which when combined with water form highly corrosive sulphuric acids. Evidence of these corrosive emissions can usually be seen in the metal parts above kilns
chlorine and fluorine may be released when clays or glazes containing fluorspar, iron chloride and cryotile are fired. Both gases are very irritating to the respiratory tract
various metallic compounds will undergo complex chemical reactions during firing. Fumes formed from lead, cadmium, antimony, selenium, copper, chromium and nickel are all toxic if inhaled; some are even carcinogenic. In addition, fumes may settle and contaminate dusts in the kiln room
Revised October 2003
4 of 6
Information Sheet IS13 Ceramics Hazards
nitrogen oxides these may be produced by the decomposition of nitrogen-containing compounds or by the action of heat and/or electricity on air in the kiln. Ozone may also be formed, and
both are strong lung irritants

[david s]

Re: Can these be used for oven floor?

I will be interested to see how they stand up to repeated firings. My guess is that being thin, they will be more prone to cracking. However as you are selling them this won't be a problem for you and it may well generate more sales from those that you will need to replace for others.

[eatingmorefood]

Re: Can these be used for oven floor?

We used 2 layers of 1 inch thick 14x16 in #2 pizza stones and the floor works great. See it here : Pizza Making Supplies, Pizza ovens, DIY pizza ovens, DIY wood oven, Cutter, Pizza Stone, pizza knife, spice shaker, crushed red pepper, grilling pizza, grilled pizza, pizza BBQ, BBQ pizzas, make pizza on grill, making grilled pizza, smoked pizza, woo

[brickie in oz]

Re: Can these be used for oven floor?

This forum is awesome, by reading it I now know too much and need to stop researching and start building!

Cool! Dont forgot we need lots of pics...