Commercial Oven Building Help

[kiwikid]

As my mobile woodfired oven business needs to expand, I am looking at building another trailer oven. My existing trailer has two mono block 900mm ovens installed which I purchased for some serious money!.

My plan is to build a 1300mm round oven using shiracast (100mm thick) for the core, then insulate with blanket, etc. I am planning on building in a stainless cylinder. The cylinder would be around 1550mm dia with a welded sheet metal floor. I was thinking then of installing the cooking floor, then building a (one use only) timber formboard frame on top of floor (one inner, one outer), mix and pour the casting between the form board layers to create the core, then blanket, then vermiculite and refract cement and small amount of sand (all inside the cylinder), then finish off by rapping another 50mil thick blanket around the outer cylinder???. comments please

[brickie in oz]

Re: Commercial Oven Building Help

and small amount of sand

Whats the sand for?

[kiwikid]

Re: Commercial Oven Building Help

1xsand,1xcement, 6 vermiculite...just part of the installation mix...does it need sand? i dont really know...just thought it would help strengthen it a little?

[kiwikid]

Re: Commercial Oven Building Help

My reason for building oven in cylinder for a trailer mounted oven is to cut down on weight and also it can then be welded to a frame that can then easily be lifted off the trailer (if required) leaving the trailer free...

[david s]

Re: Commercial Oven Building Help

1xsand,1xcement, 6 vermiculite...just part of the installation mix...does it need sand? i dont really know...just thought it would help strengthen it a little?

Yes, adding sand will increase the strength, but don't forget that it also reduces the insulation value. You can increase the thickness to compensate for this, but then of course you are adding exta weight.

[lwood]

Re: Commercial Oven Building Help

Don't see why you need the sand, your just insulating not supporting. The cement is there just to bind the vermiculite together. I wouldn't use that insulating layer to support anything, even with sand. Particularly on a mobile unit. I have seen where people have used a steel pan, built onto the trailer to hold the insulating layer and built directly on top of that. But you have indicated that you want it removable. I believe that would make the design much heavier, because you with be building a frame to carry the entire oven. I'm sure you have you reasons to make it removable but that is a tough one.

Didn't see any insulation under the floor. "with a welded sheet metal floor. I was thinking then of installing the cooking floor" You need insulation under the cooking floor.

[kiwikid]

Re: Commercial Oven Building Help

Thanks for the feed back ...you have both talked me out of using the sand (Great less weight!). I am thinking the oven complete will weigh between 1000-1200kg, but may reduce my side wall thickness to 80mm and keep the roof/dome at 100mm. The base will be around 200mm, with 70-75mm x 300 x 300 firebrick tiles, underneath tiles I was thinking of a mix of verm and refract cement(90mm), then on top of this 40mm of calsium silicate then the tiles??.

I think this way there will be great installation under the floor but without much weight being added? I need the floor well insulated as at some events we are cooking over 1000pizzas in a day/night and I cannot afford to lose the base heat.

As this will be the first time I have attemped to build a cast oven myself (have built several brick based ones) I am looking for your opinions and any suggestions that might smooth the way a little. I have decided to build this one because I think I can, and also they cost around $8-9 thousand for one this size...thats a lot of money!

Couple of questions:
I have heard that the product, shiracast 140, would be a great lasting, strong product to use for the core, has anyone here used this or simular high density casting materials? and what was your opinion? do they match up to what is used by commecial oven builders? or is it merely what they actually use?

Should I also mix in stainless pins to add some shock resistance (being that it is mobile) or is this just overkill?, or not really required?

Thankyou for your advise so far please keep it coming.....

[windage]

Re: Commercial Oven Building Help

Check out the 54" ID oven that my friend just finished on a trailer. Pics are at the end of my "81 inch first build" thread in this commercial section. He built that on a steel pallet, with a steel girdle and steel arch. Built from firebrick with "perlcrete" cladding over chickenwire..not much cash in it and fires real good. NO sand in your perlite mix, it's fairly strong...you may try fibers though.