What's the best mix to cast a refractory oven?

[cannyfradock]

Hello Luke

Lots of people are viewing this thread but is seems no-one....including me has any first hand knowledge.

I found this site which gives you the materials to us and plans on how to go about building an oven with refractory concrete...hope it helps...

howjunction.com/2022/in-the-garden/how-to-build-a-free-form-bread-oven-1/

Terry

[slowfood]

The easiest and quickest way is to build your inner dome out of wet sand and cover with wet newspaper and then cover with refractory concrete, Simply remove the sand when built and the paper will burn off, For the floor use refractory bricks (often called fire bricks) Often on ebay used. Good luck, See my build ukwoodfiredovenforum.proboards.com/index.cgi?board=modovensongoing&action=display&thread=253

[cannyfradock]

Luke

While Slowfood is getting back to you...." calcium aluminate cement"...is fondu cement (you can order it from any builders merchant)...usually made by "lafarge". It has a high alumina % which works well for our purposes, but......and it's a big but.......it goes off rapid in a short time, so large mixes with the stuff simply won't work.

This is my bricklayer/building experience with the stuff, so I hope Slowfood gets back to to clarify things.

Terry

[cannyfradock]

Luke

Those were just suggestions...and a link that I found. I haven't used these products before and haven't built an oven using refractory concrete so I can't really give any first hand advice.

Hope slowfood gets back to you as I believe he has quite a bit of knowledge on this subject.

The only person I know who sells refractory concrete to the public is Liam from www.kilnlinings.co.uk/ .....he also makes and sells his own modular ovens so perhaps he won't give too many secrets away?.....but he is very phone friendly and give you advice.

Bank holidays and weekends are usually quite quiet on forums, so bump this thread next week......you may get others interested.

Terry

[slowfood]

Hi, I made the mould from ply, plastic, cardboard, wood, cardboard, silicone, filler, plaster, varnish, blood and sweat. I didn't build the oven to sell but there are many people selling them on ebay. TBH my materials cost me more than I could buy the whole oven kit on ebay, I don't know how they do it so cheaply. There are loads of places which sell refactory cement to the public, I called them all and think I paid about £12 per 25k 1300c sack, Some places wanted more than double that. Good luck.... I am also a mould maker (Shuttering Carpenter/Steel Fixer)

[slowfood]

I would not cast the oven in one piece personally for a few reasons, One main reason it will probably crack due to no expansion joints or crack inducers. The other is that it will be far to heavy to move should you want. However if you plan to keep the oven in the same place and don't mind the odd crack ( I am sure all ovens crack anyway, You can always seal the cracks with fire cement).
I allways recommend Russel Jeavons book "Your brick oven" to people, I had never laid a brick in my life and completed a good sized oven in a day including arch, The beauty of his book is he also explains why you don't need to waste money on firebricks, (Well you'd need them for the floor" A brilliant book