what exactly is fire clay? Newbie Forum Discuss what exactly is fire clay? in the Good Background Information forums; Hello I've heard 2 definitions of fire clay: 1. Normal potters type clay. Dried and powdered 2. Crushed up fire ...

[mickfitz]

Hello

I've heard 2 definitions of fire clay:

1. Normal potters type clay. Dried and powdered
2. Crushed up fire bricks

Can someone please 'finally' tell me what it is?

I live in the UK so if anyone knows where I can buy it I'd appreciate any advise

Thanks in advance

Mick

[dmun]

It's a naturally mined clay that's high in alumina which gives anything made out of it refractory properties. It is a special type (there are hundreds) of dried and powdered clay.

For some purposes, like leveling the floor of your oven on an uneven insulating surface, the slurry from your wet say (crushed up fire bricks) will work as a good substitute. For others, like making homebrew refractory mortar, it's not so good.

We've heard about the difficulty of sourcing fireclay in the UK. I'm afraid I'm no help there.

[mickfitz]

Thanks for the reply. Everything for the oven dome in the UK is either difficult to source or expensive to buy!
I'll keep trying

[david s]

Fire clay is a dried powdered clay that is highly refractory. That is its ability to withstand thermal shock and its resistance to melting (eutectics). In Australia some bricklayers use fireclay to add to their mortar to give it a stickier consistency. The stuff is not true fireclay, it is not particularly refractory and is now being relabelled as bricklayers clay to avoid confusion. Get fireclay from a pottery supplier or a refractory materials supplier.
Having said that it is possible to build an oven from mud and it will work. We tend to use materials which have characteristics that may exceed the reqiurements.Fireclays melting point may be over 1500C and we're only firing up to 500 C.

[mickfitz]

Thanks for the reply. After all my searching I've managed to find a supplier a few miles from me!

[hulkiebear]

I have 2 bags of fire brick off cuts, that would be easy to crush up and make into a home brew mix. I did make some myself, which worked well.

you are more than welcome to have them for free if you are close enough to me to pick them up!

[mickfitz]

Well that's very kind of you. I'm in Warrington Cheshire ... where are you?

[hulkiebear]

Ahhh, I live in Weston-Super-Mare, unfortunately not so close!

But you are more than welcome to it, if you can think of a way of transporting it!

Lee.

[mickfitz]

I think the transport costs be crazy mate. many thanks for the offer

[castiron]

I used nothing but fire clay for my oven.It is not in it's permanent location so that is why I used fire clay.Got my design and information from the Masonry Heaters Asso. I must say it has worked great.I have fired it up at least 2 dozen times and is still holding up great.Good luck and here are a few pictures.Not pretty but cooks a mean pizza.