the 3rd way

[sonomacast]

I cast an oven in situ with refractory Cement some years ago.
recently I built a Pompey oven using housebrick and now I want to build the 3rd way.
I want to build forms which can be used more than once, to cast a few ovens. Like the precast ovens sold around the world.
How are the oven components poured? Is the oven cast in one then cut into the seperate components or are the components cast seperatly. If I were to use refractory Cement what type is best. when set does the material need to be put in a kiln or what?
I was trying to find photos of manufacture process on the web but to no avail. Thanks

[texassourdough]

Re: the 3rd way

Sounds like you are about to be the local oven gut supplier in Costa Rica!

My oven guts appeared to have come out of separate molds. That would be a lot of work but... The top was four sections - one of which included the entire door. The floor was four pie shaped pieces IN the oven and one that filled in between the circular floor and the door. I don't know anything about the cement.

I haven't been to that Costa Rica yet but my wife and I plan to visit in November! Looking forward to seeing it. Supposed to be a great country.

Good Luck!
Jay

[sonomacast]

Costa Rica

Yes, CR is great, be carefull with your timing as it could well be raining in November. I personally like December as there are cool winds and everything is still green from the rain season. We have just built a couple of houses which we hope to sell and natrually there is an oven. I enjoy looking at the oven more than the houses.
there are some older photos here... Flickr: Jasonsplace's Photostream

[texassourdough]

Re: the 3rd way

We will be on a tour with three days in the rain forest, three days in Guanacaste, three days on the beach and two days in the jungle. Your rain warning will be heeded.

The houses look great. Good luck!
Jay

[sonomacast]

Re: the 3rd way

any ideas how i can cast a modular oven please

[texassourdough]

Re: the 3rd way

I would think the biggest challenge you would have is getting refractory cement... though I have no idea what they used back in the 1700s! I have a feeling an awful lot of European ovens are not refractory grade!

I would, I think build a mold of the oven cavity. I.e. use something like cement and rocks or plaster of paris or something to make the interior including the door to the flue. The outer inch or so should probably be cement with a smooth suface. That could be waxed to insure release. You can probably use masonite cut into arcs to separate the pieces of what will be the dome. Again, wax them good.

The question is how to contain the outside of the dome...or if you need to. You could conceivably simply use some metal bands (hoops/rings) of gradually smaller size to contain the concrete and lay it up ring by ring. That would give a funky exterior but... would be pretty easy. Another possibility would be to make the external forms from sheet aluminum (thin) supported by a wood frame to hold/keep the shape. You might need a complex set to insure you can get the concrete into the corners of the form...

I bet if you ask around you can find some creative Costa Ricans who can figure this out and will do it cheap!

Good Luck!
Jay

[Wiley]

Re: the 3rd way

As an off the wall idea: how about inquiring (off Forum) of James on the possibility/idea of you becoming the representative/distributor for Forno Bravo in Costa Rica? Why not all of Central America? You may have to learn a new skill set and perhaps become acquaintances with someone who is already importing from US (or direct from Italy) to share a container on a now and then basis, but perhaps there is something to be gained for all concerned.

Bests,
Wiley

[texassourdough]

Re: the 3rd way

Good idea Wiley!
Jay

[sonomacast]

Re: the 3rd way

the ovens are only around $400 in Italy but the shipping is too much, Anyway the enjoyment is in the construction for me. I have built 2 ovens but don't use them, just like to build them. build costs are minimal, refactory cement is not too much money.
I guess the way to go would be to form the interior dome and door with damp sand, cover with wet paper then coat with a lot of fibreglass and sand later. do the same with the exterior. build a bigger dome with sand, paper and plaster, sand, cover with fibre glass, remove later and sand the inside. these 2 fibreglass forms would need reinforcing with ply ribs. Another problem would be to keep the space correct between the moulds. I guess some 3" bars of pre made refractory concrete spacers would do the job. Finally which would be better, pour from the top (ie keep the top of dome open for pouring) Or pour from the bottom (ie dome upside down) And finally cut the finished oven into segments when it has cured natrually. This is all I can think of, but Id like to know how they manufacture the ovens in France, Italy and Australia, as i am sure there is a simple way to form the segments separately. Any ideas?

[texassourdough]

Re: the 3rd way

Your idea sounds pretty good. I think I would fill from the bottom. I.e. hold the mold upside down. You could make sections... If you have four sections you could make three of the sections from one mold (a simple quarter dome). The fourth section would have to include the door. which would be a lot more complex. But it would avoid having to cut the dome.

Jay