Oven clay reuse help

[tim_n]

My previous oven survived 2 years before it really needed a revamp. The clay is London clay and has baked to a red brick colour. It's very crumbly and when I add water seems to go back to a sticky though lumpy clay. Can I reuse this or is it best to dig a new load?

[tim_n]

Re: Oven clay reuse help

Looking at the clay, I don't think it has small enough particulates make a true clay (even though it's sticky) I'm now thinking of digging more up and using the old fired clay to back fill the hole.

The clay I do have:



seems to be about 1:3.5/4 - so I'll probably need to add two buckets of sand for every one of clay? Sound reasonable? Using B&Q Sharp Sand.

[tim_n]

Re: Oven clay reuse help

Now (currently) baking some clay/sand mix bricks in my domestic oven! I've discovered that my clay is 1 part sand to 2 parts clay, therefore I need an additional 50% by volume of sand to make 1:2 clay to sand ratio! Details of my experiential is on ? Further clay experiments Waark!com allotment and green living blog

[david s]

Re: Oven clay reuse help

It is possible that the surface of the clay that was closest to the fire, particularly at the top of the dome may have got hot enough for some of it to be sintered ie having reached 573C in which case it will be difficult to return it to a powdered state. You'll need to do a lot of pounding.It may be less work to start again

[tim_n]

Re: Oven clay reuse help

Thanks David, I'm fairly sure I got to the 700'C+ range as I could cook a pizza in about 30 seconds. The entirety of the dome colour/material was consistent, so I've definitely got the thermal mass up to temperature! I was wondering if I could reuse this material somewhere rather than putting it back in the ground!

[david s]

Re: Oven clay reuse help

Yes you could, but like I said, if it has been sintered it won't return to mud, it has been made permanent and will require crushing. You could try wetting the stuff down and sieve and discard the sintered bits instead of crushing them.