ovenware

[Mark M]

Hello I wanted to make something to use in the oven, what is the best clay to use? and what are the best food safe glaze to use?

Thank you

Mark

[Bill Kielb]

Robby Label does flameware which is designed to be very resistant to large temperature changes. Ovenware however is a bit of a different story. Many use a reasonably strong stoneware which there are many. Have even seen folks throw Bmix for ovenware. A couple points to know, any glaze that fits the body well and is food safe is probably a good choice. This takes testing for compatibility of the claybody and glaze used so it’s hard to suggest but perhaps folks here will share their favorite combination. Clay and ovenware are not the best mix however so in general  Safe practice usually dictates  the pot should be reasonably full and not necessarily put in a preheated oven. Basically techniques that minimize the thermal shock.

Flameware on the other hand tolerates shock well but ....... glazes are specially formulated for these bodies as they usually require a very low coefficient of expansion.

Food safe in the US simply means no lead or cadmium, but many potters also avoid heavy metals and excess metals. Often a white zircopax liner is picked for the inside for this reason. Commercial glazes are hard to know the durability of without testing, especially with a particular claybody.

So in the end, not a direct answer to your question but as you can see from above there are many things potters spend a lifetime learning. It’s truly Art and science, quite often without a simple answer. It is great fun though, and educational.

[Min]

As well as glaze fit and preferably a low expansion clay and glaze the form of the pot used for ovenware is important too. Even wall and base thickness, avoiding sharp angles where the wall and base meet, rounded bottoms vs flat bottoms if possible (a wide flat slab base is going to have more issues with uneven heating than a smaller rounded bottom shape). Handles and knobs that are easily and securely held with oven mitts and easy to clean galleries if it's a lidded pot and easy to clean glazes are other considerations.

Welcome to the forum Mark M.

[Sorcery]

Every ovenware recipe I've found is either Cone 9 or 04.

https://standardceramic.com/collections/clay/products/762-kitchenware-clay

Premixed too.

Sorce

[neilestrick]

Any decent vitrified stoneware, cone 5/6 or cone 9/10, with a well-fitting, durable glaze can be used in the oven. Just don't preheat the oven, and make sure your forms are even in thickness.

[Pres]

I have been throwing casseroles, bowls and other items for use in the oven and microwave for years. Most of these are with ^6 stoneware from SC. I have made some mistakes mostly by using large range firing stoneware bodies that did not fully vitrify at ^6. The 112, and the 620 or even the Hazelnut brown seemed to work well in the oven. We use bowls to bake in, and make buffalo chicken dip, apple bakers for the oven or microwave, teapots that I heat water in the microwave, and some fish platters and other low wall pieces.  

I think in the long run with a good liner glaze, a sturdy piece with well thought out design will work well. Use them like glassware for the oven as Neil says, don't preheat. Also don't freeze and bake, let thaw. Don't refrigerate and then heat, let the piece get to room temp then in to the oven, that only takes a few minutes.

With slab pieces, I have often found it best to use a form to create the piece so as a single slab can make bottom and side of the piece.

 

best,

Pres