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Post by webbaldo on Feb 25, 2012 13:41:31 GMT
More and more of these lightweight ovens seem to be popping up for sale.  Im not bothered about the business side of things but I am keen to see how they are built. Ive got a bernito one myself. I really fancy having a go at building a mini one to take away on trips etc. Obviously the sellers wont give their secrets away but does anyone has any information on their construction? I cant find anything anywhere. The base if deffo a kind of fibreglass, outer shell has a thin gel-coat like layer and at a rough guess I think the base inside is some fibre board coated in fire cement. This is all speculation like. Anyone care to add? |
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Post by cannyfradock on Feb 26, 2012 12:26:46 GMT
Webbaldo
I haven't got the answers....just a few idea's on how to construct one. I hope this thread sparks up a few more responses.
Terry
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Post by webbaldo on Feb 27, 2012 11:07:09 GMT
Webbaldo I....just a few idea's on how to construct one. Terry wanna share? lol |
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Post by cannyfradock on Mar 2, 2012 15:33:06 GMT
My idea's are only vague......using a perfect sand form to create a fibre-glass mold, then using a refractory concrete of fine crushed clay aggregate mixed with powdered fire-clay sand and cement, using inlaid mesh or chicken wire as re-enforcement. I don't think I am even scratching the surface of how to cast your own Modular oven.......If you wanted more suggestions on the subject, why not start another thread but instead of the title "lightweight ovens".....use something like " How to cast your own modular oven"......it may sound long winded but would possibly start an interesting and popular thread  Terry |
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Post by ruralidle on Mar 2, 2012 22:07:33 GMT
I think that the black base is silicon carbide and although the base has some fibreglass as an outer shell it also has special insulation boards. Given the (lack of) thickness of all the insulation on Bernito ovens and the low temperatures that the outer surfaces achieve, even with high internal temperatures, I would suspect that some fancy, high tech, materials (read - expensive) are used.
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Post by webbaldo on Mar 6, 2012 12:38:38 GMT
I think that the black base is silicon carbide and although the base has some fibreglass as an outer shell it also has special insulation boards. Given the (lack of) thickness of all the insulation on Bernito ovens and the low temperatures that the outer surfaces achieve, even with high internal temperatures, I would suspect that some fancy, high tech, materials (read - expensive) are used. thanks for the ideas, ive started a new thread in the casting your own oven section. Even though expensive, if you can do it yourself surely itd still be cheaper than buying an actual oven? |
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Post by turkey on Mar 6, 2012 21:17:24 GMT
I think that the black base is silicon carbide and although the base has some fibreglass as an outer shell it also has special insulation boards. Given the (lack of) thickness of all the insulation on Bernito ovens and the low temperatures that the outer surfaces achieve, even with high internal temperatures, I would suspect that some fancy, high tech, materials (read - expensive) are used. this made me think of some ovens I have seen advertisied, Kiln Linings describes their oven as "THIS KIT ICLUDES 5 EXTREMELY EASY TO ASSEMBLE PIECES MADE FROM THE HIGHEST QUALITY INSULATING REFRACTORY CONCRETE" perhaps the high tech stuff is actually picking an insulating material that will retain enough heat itself in the inside face to cook the pizzas. ? |
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Post by webbaldo on Mar 7, 2012 8:41:56 GMT
I think that the black base is silicon carbide and although the base has some fibreglass as an outer shell it also has special insulation boards. Given the (lack of) thickness of all the insulation on Bernito ovens and the low temperatures that the outer surfaces achieve, even with high internal temperatures, I would suspect that some fancy, high tech, materials (read - expensive) are used. this made me think of some ovens I have seen advertisied, Kiln Linings describes their oven as "THIS KIT ICLUDES 5 EXTREMELY EASY TO ASSEMBLE PIECES MADE FROM THE HIGHEST QUALITY INSULATING REFRACTORY CONCRETE" perhaps the high tech stuff is actually picking an insulating material that will retain enough heat itself in the inside face to cook the pizzas. ? Ive been looking at kiln linings website, and my bernito oven chimney (and im assuming base) looks like it has something like this below the cement layer kilnlinings.co.uk/index.php?main_page=index&cPath=15 |
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Post by baronkev on Mar 14, 2012 17:27:30 GMT
Any ideas what kind of insulation is used in the dome? It would have to be something with pretty good thermal values to be so thin and light dont you think? Can these materials be used in a regular build?
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Post by slowfood on Apr 3, 2012 19:58:32 GMT
surely refactory concrete should not insulate as it has to soak the heat
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Post by tonyb on Apr 8, 2012 8:41:30 GMT
Wikipedia defines refractory as material that retains its strength under high temperature but within this definition refractory materials cover a wide range of thermal, physical and mechanical. Choosing a refractory material for building a wfo is all about trading off the mechanical, thermal and physical properties of different materials based on the type of cooking you want to do, cost, structural permanence, convenience etc.
You are right that the standard firebricks and high density refractory concrete are generally chosen to hold the heat particularly for retained heat ooking eg baking multiple batches of bread. However, there's nothing to stop you building a wfo out of low density (insulating?) refractory materials, but you'd have to change how you operate the wfo and maybe not be able to cook the same range of food.
Maybe in the discussion of 'insulating' firebricks we maybe being a little cavalier with the term 'insulating'.
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Post by slowfood on Apr 14, 2012 23:18:50 GMT
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Post by Fat Bob on Apr 15, 2012 11:39:32 GMT
We have been using our experimental Zero Thermal Mass pizza oven for some months now. It uses far less wood than firing up a big heavy oven - it is ready to cook within minutes. A few sticks will cook a lovely pizza plus the pizzas have a mildy smokey flavour.
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Post by slowfood on Apr 15, 2012 15:42:03 GMT
are you using perlite mixed with refractory?
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Post by tonyb on Apr 15, 2012 22:07:16 GMT
You don't need a high thermal mass oven or an over-sized heat source to cook pizza in a domestic situation. In fact, I suspect you need less fuel as there's much less material to heat up.
The benefit of the thermal mass comes into play when cooking something slow say a shoulder of pork overnight, or you are baking bread, as this is done without an internal fire, using heat retained in the oven's thermal mass. The extra thermal mass and good insulation mean a slower cooling cycle.
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EUREKA, The secret is mixed refractory cement mixed with Perlite (Maybe 50/50) and possibly stainless steel needels for reinforcement, Just an idea but I think it would work. I'll try it next time I have some refractory mixed. but I don't get it, For an oven to work you need one of two things. Thermal mass surrounded by insulation OR a small amount of thermal mass with a hugely over sized heat source.