Rustic Primitive Materials

[Laurentius]

Re: Rustic Primitive Materials

Hi Annie,

Glad to hear that you are still around, taking your time. Hang in there. Cooked our turkey, dressing and bread in my over, tomorrow cinnamon buns and rye bread.

[mrchipster]

Re: Rustic Primitive Materials

I am sure the foundation you have provided will drain well but I think a water proof barrier between the foundation and the hearth slab may also be a good idea, someting as simple as a piece of sheet metal would do the trick. Water may wick up through the foundation you made and cause problems with heating without some form of barrier.

Chip

[Tscarborough]

Re: Rustic Primitive Materials

That looks very nice, but it is still a flexible surface and you will need an inflexible surface for your oven. As you appear to have some batter to your wall, you will probably also want to cantilever the entry out over the wall a bit so you will not have to lean over to work the oven.

[mrchipster]

Re: Rustic Primitive Materials

You will want to use a running bond in the dome to increase its strength.
If you look at a traditional brick wall it is a running bond where the bricks are staggered.

Chip

[brickie in oz]

Re: I am sooooo stubborn!

Annie... who has managed to capture wild yeast!!!

I caught some wild yeast years ago when I went to the top end of Queensland, had to get some ointment to get rid of it.

[azatty]

Re: Rustic Primitive Materials

Cut down the cast iron for the oven door, and then use the rest to build a brazier near the oven for grilling.

[brickie in oz]

Re: Rustic Primitive Materials

I think you will be sorry if you put that scrap iron under the floor, it will move and twist from the heat, its already cracked.
One layer of brick is fine unless you are building a bake house.

[david s]

Re: Rustic Primitive Materials

I think one layer of bricks for the floor is plenty, especially if you also intend to use the steel plate under it. Two layers will take ages to get to temp. Can't be sure about the steel buckling from the heat, but I would think that because it is not getting direct flame impingement and the heat source is further away, it should be ok. I have seen plenty of 1/4" barbeque plates that have buckled, but I don't think a 1/2" one moves a bit. I've never heard of anyone trying a steel plate under the floor before so can't be sure how it would work, but an old Italian trick to increase thermal mass to extend cooking time, for certain cooking applications, was to throw in a couple of truck axles. This would reduce cooking area drastically of course, a problem your idea overcomes.

[wotavidone]

Re: Rustic Primitive Materials

Annie, If cob is all the rage in your area, get the gang around and have a cob oven building weekend. From what I've heard and read, a cob oven can materialise that quickly.
Then you will have somewhere to cook, while you get organised to build a flash whacko fully insulated brick oven.

I was hoping that the more experienced oven builders on the forum might have added their opinons about the floor thickness by now. Don't make your decision just on my comments, please.
Regards,
Mick

[Laurentius]

Re: Rustic Primitive Materials

Annie, once its up and running, you will forget about pizza, you'll be thinking, breads, stews, casseroles, bake potatoes, dried tomato, baked hams, candied yam and sometimes peanut butter and jam-----------pizza. Dream on, make your dream come true.

[deejayoh]

Re: Rustic Primitive Materials

Annie -
fellow NW builder here. Take a look at mcgillswarehouse for your blanket and insulating board. You can insulate top and bottom for ~$200. Rustic ovens are cool, but insulation is really the thing that makes modern ovens so much better than roman ovens.

[Laurentius]

Re: Rustic Primitive Materials

Hi Annie,

Yes, you can mud cover your bricks or even go totally cob. But now it seems as if you have community interest and offers to help, If I were you, and I have been you in respect to my oven. I would build the most efficient oven I could and the first concern after size would be insulation. A well insulated oven will allow multiply uses during the week without having to use more fuel with little or no maintaining. Three(3) inches of ceramic blanket is recommended for the dome and two(2) inches of ceramic board for the floor. I see the wheel spinning in your mind saying,"What the hell am I getting myself into"? It will take about the same amount of time to do something (half-assed, something my mother used to say to me) as it would to do it right. If you are having doubts(don't do anything for a while, thing about it). Word of caution: Take no advice from Cob Ovens Builders, if they mention glass, sand, mud-straw or fiberglas as insulation for an oven.

[wotavidone]

Re: Rustic Primitive Materials

Annie,
Have your read the plans that Laurentius posted yet?
I ask because, even if you don't actually follow them, they give some good guidance on the basic dimensions and concepts.
There is a need to balance the amount of thermal mass in the dome against the mass in the floor.
I'm a bit concerned about your intention to have a layer of cast iron topped by two layers of brick. I am interested to know how thick that would make your floor compared to your dome.
Most builds seem to have a single layer of full thickness fire brick for a floor.
The floor is heated mostly by reflected/radiated heat from the dome, and if there is too much mass compared to the dome, you may end up with a large temperature differential.
What do more experienced builders think?

[brickie in oz]

Re: I have a plan!! ...almost

a prototype dome using angle iron for supports to test the design and see how it holds heat before I do anything permanent with mortar.

The steel will buckle with the oven heat.

[brickie in oz]

Re: Rustic Primitive Materials

I made a little progress today... I hope.

I was able to acquire some new firebricks at what I hope is a reasonable price (1.25/1.45) for split and full bricks. However they were just on a pallet with no manufacture identification but I jumped in anyway and purchased some.

The splits weigh 3 lbs 9.5 oz & the full bricks weigh 6 lbs 8 oz does this sound like the correct weight for the type of brick usually used for the oven floor?

Fingers crossed... Annie

Sounds good, the heaver the brick the denser it is.