Cast base?

[fox]

I am considering buying the linked 750 DIY oven, it will cost me no more than buying dense refectory materials to cast my own.
My question is ... the design uses a 2" base that fire bricks can be placed on, is this a good or bad thing?
Thanks Fox.

http://www.pizzaovensupplies.co.uk/pizza-oven-kits/

[dakzaag]

Well, unless you have a way of suspending bricks in mid air, a base to set the floor on is always a good thing. Is the base you are looking at buying a good one? No way to tell. I would suggest that you get what you pay for. In this case, the price is cheap, so the oven is going to be cheap. Insulation looks to be sparse at best and I would buy you a pint or three if you can complete the build in less than two weeks of nights and weekends since you have never done this before. If it is a choice between ordering this oven or no oven, then I would order this oven. If you can scrounge up a little more money, you can build a much better oven with materials you source yourself. (assuming Guernsey has some very basic masonry materials. )

[dakzaag]

I spent a little more time looking at the link, one thing about the Forno Bravo site is the new guys keep dragging in odd bits and pieces from all over the earth to look at.

Remember you are just buying a slab and dome that is described as light enough for a couple of fellows to lift. Common materials that just about any masonry yard will have can create this same structure for $50 (US.) If you step up and order the kit, then you are pushing $1,000 (US) with shipping etc. That same amount will build a really nice oven if you can source the supplies. But it is a lot easier to ring the dealer up and swipe your plastic and next thing you know an oven appears at your front door. Well, parts of an oven...

[fox]

Hi dakzaag, thank you for your reply.
I have already built the base & it has 5" of vermiculite cement in place, I was not sure if I just had to set the fire bricks on top of the vermiculite?
Or do I have to use a more solid base under the bricks?
I don't know much about the oven in question other that what I can read on the site. It says the oven is made from fondu cement, fire brick grog & perlite. they are cast in steel moulds & vibrated.
In Guernsey we do have builders merchants (building is big over here) but no specialist that can offer clay or ht cement, so I will have to import anything like that myself.

[fox]

Now that I have studied the site, I discover that this oven design uses Perlite in the refractory mix.
I am a little confused with this ....... http://www.pizzaovensupplies.co.uk/pizza-oven-design/

[jonv]

Doesn't make sense to me either. I've come across several like that, with perlite or vermiculite as part of the mix. As far as I can see, adding light weight and insulating material like that is the opposite of what you want. There's a good reason why the ovens here are made with a dense refractory material on the inside and insulation over that

[david s]

Now that I have studied the site, I discover that this oven design uses Perlite in the refractory mix.
I am a little confused with this ....... http://www.pizzaovensupplies.co.uk/pizza-oven-design/

They also use a 5" flue for all their ovens. Most builders would consider a 5" flue inadequate for anything larger than 24" dial oven.
Not only will perlite in the castable refractory make the mix less dense, it will also make the casting weaker and more subject to abrasion damage.

[fox]

OK thanks for the conformation, I wont be getting that model then!