Tanzania/Canada

[SteveS]

Hello to all Pizza Oven Builders and Users!
My wife and I live in Simcoe, Ontario, Canada. 18 months ago we started an Orphanage in Usa River, Tanzania. It is a small village located between Arusha and the Kilimanjaro airport. For any of you interested our site is tuchifo.com helping children in East Africa.
We are here now and my wife is experiencing great success in teaching staff to prepare more healthy and nutritious meals for the children. We struggle however with the inefficiency of the cooking methods traditionally used here.
I am here until early March and am committed to make a wood-fired oven.
As you can well imagine obtaining materials for propper construction is always a challange in Africa. I am a farmer by trade and can pretty much make or fix anything with almost nothing.
Before I start searching for materials I thought I would post this thread to see if anyone has had experience in the Arusha area with aquiring fire brick or if indeed anyone has actually built an oven in this area.
Thanks for any help anyone can provide!

[SteveS]

Re: Tanzania/Canada

Just another quick question. Has anyone used any other material other than vermiculite to mix with cement to form an insulating concrete layer? Is it even nessessary in such a hot climate as this?
Thanks again for anyones help on this!

[cobblerdave]

Re: Tanzania/Canada

hi
Don't know how you will go with obtaining fire bricks in africa as they are an item that seems to come with industry.... Perhaps you might want to investigate building a COB oven its a fairley traditional style of construction that uses local materials mainly clay and straw. The main disadvantage is that it is not as water proof as the more modern methods but with the addition of a good cover to keep it out of the wheather and a bit of plastic waterproofing to stop the water wicking up into the structure could could build an oven to suit the local supply and conditions.
Same as with the Forno oven.... insulate the hearth and the oven is inportant.
You could possibly check out the forum there are quite a few of our Phillipino friends who are quite inventive and have build a few ovens with local materials

God bless
Dave
Brisbane Australia

[SteveS]

Re: Tanzania/Canada

Thanks for the ideas Dave and I will check out some of the Phillipine construction if I can find it.

[Tman1]

Re: Tanzania/Canada

While fire brick is best, you don't have to give up on a WFO just because you can't find them. Check out my build for ultra simple (and cheap!). The biggest thing you need are clay bricks, not concrete. Good luck!

[cobblerdave]

Re: Tanzania/Canada

Hi again its dave back
I checked out a bit of old information I had when first investigating building a WFO again Cob style oven could possible be you best option. I say this because if you cant get Firebrick he chances of getting a fireproof cement would be low as well. Even making a homebrew fireproof cement involves getting hold of fireclay which is basically ground firebrick.
Perhaps a hybrid oven... If you can get hold of some fired clay bricks ( not Cement ) you could build the oven floor and a layer of bricks around this then continue the dome in cob constuction. The floor doesnt need to be cemented but layed dry. This would give you a harder wearing floor and surrounds that would put up with the daily bumps and scratches of peels and tools.
From what I have read a cob oven should give you years of use its biggest enemy is moisture, I live in sub tropical QLD so I didn't go down that path myself
Regards Dave

[Wiley]

Re: Tanzania/Canada

Steve,
I assume you have read thru Janine's thread about building a WFO in Uganda, if not it's worth checking out.

http://www.fornobravo.com/forum/f3/h...anda-7728.html

Bests,
Wiley

[SteveS]

Re: Tanzania/Canada

Thank-you very much Wiley, for pointing me in the direction of Janine's thread. I just finished reading through the entire thread. Very inspiring!

I am preparing my construction supply list today and will hopefully begin the base tomorrow. I will try to photograph and post my progress. I think my biggest concern right now will be trying to keep the all the children out of the cement!

Thanks again for everyones replies!

[cobblerdave]

Re: Tanzania/Canada

Just another quick question. Has anyone used any other material other than vermiculite to mix with cement to form an insulating concrete layer? Is it even nessessary in such a hot climate as this?
Thanks again for anyones help on this!

Just thought Id put down a few main points
Dome and Hearth floor.....This is your heat bank takes the heat from the fire stores it and throws it back in the oven even when no flame is present if you have sealed off the oven. Im assuming that you will go dome its the most effective. The entrance is 60% the height of the oven and the chimney is external to the entrance...the heat from the fire has to stay in the top of the oven longer and gives its heat to the structure (your heat bank)
Does it need a chimney? well no... the chimney just funnels the smoke away from you face... well that can be important to. How can the fire breath? just trust me it does
Insulation..... Both Dome and Hearth floor insulation is very important perhaps the most important of the lot. You have spent time and wood the get he heat into the structure of the oven and without insulation youll reach the point when the heat just ends up heating the Base and from the dome youll be trying to heat all of africa. Just imagine driving your car heater on with all the windows down, the heats just disappears from the car even running the heater flat out.Put the heater off (fire out) and it cools down real fast. Roll those windows up and you would probaly turn that heater down. Turn the heater off with the windows up and the heat would stay for a good period.
What to use as an insulation layer under the hearth perhaps a layer of rough sand. Over the dome a layer of clay or clay soil filled with chopped hay. cow dung and clay soil.
Regards dave

[brickie in oz]

Re: Tanzania/Canada

in such a hot climate as this?

Hot as in 40 degrees c?
Not hot as in 600 degrees c in a wood fired oven.

Of course you need insulation unless of course if you live on Mercury or Mars.

[david s]

Re: Tanzania/Canada

Perlite is an alternative insulating material to vermiculite if it is available to you. I have also heard that manure can be used successfully as an insulating material. I think it is mixed with cement around 10:1 Presumably manure with a high undigested fibre content like dried horse manure. We live in a hot climate, usually 20 C min. 30 C max and I think in our climate you don't need quite so much insulation. We often get a bit annoyed because we have to wait until about 11 pm, with the oven door off, to get the oven temp down enough to bake bread or pastry desserts. We are currently waiting for an approaching cyclone to clobber us. It comes with the territory for living in the tropics.

[david s]

Re: Tanzania/Canada

Steve,
You may also be interested in Rocket stoves. They are amazingly efficient and ideal for third world communities. Do a google search, there is plenty of info. Only need a few sticks.
Dave

[Wiley]

Re: Tanzania/Canada

Steve,
I have neighbors with cob WFOs they have no insulation like the high tech stuff most of us here have in our WFOs. That being said they manage to pull off a single bake of bread without problem. I never have seen them try to do a second bake and suspect it might be problematic, but perhaps not. However, a single bake is all they require so it fits their purposes well.

Also, (and this is something very much (IMHO) worth taking into consideration) how easy is it to get wood for the proposed WFO? Where I live wood is no problem nor is it for my neighbors. It's free save for the cost in labor to cut and split. So the fact that my neighbors cannot bake using the saved heat the following day is of little concern. But where you are building this WFO is wood freely available or like many places here in the US you have to pay for it, or have it brought in?

If it is the latter, then perhaps figuring away to insulate the proposed WFO would probably be worth the hassle.

Hope this helps,
Wiley

[david s]

Re: Tanzania/Canada

Mud used in a cob oven is actually a pretty good insulator. A friend who built a.mud brick house up here in the tropics has a home that is so cool you'd swear it was air-conditioned.

[SteveS]

Re: Tanzania/Canada

Hello All,

It's been a week since my last post and I thought I would share an update and some photos. Construction was delayed until mid week as a number of emergency repairs cropped up that needed tending to.
For the most part we were able to work on each component of the hearth/stand every day since Wednesday.
Wed.-footings and floor
Thurs.-walls
Fri.-arch over opening
Sat.-hearth
After every step we have continually kept the concrete/mortar moist for slower curing resulting in hopefully a harder finished product.
Tomorrow we install our insulation layer on the hearth, wherein lies my next question. I have read about the different ingrediants to mix with the concrete. I haven't had any success to date finding any vermiculite or perlite. In the a.m. I am going to a nearby dutch rose growing facility to see if I can get a little of either. Failing that, a local brickmaker suggested that I might try rice husks
He uses them when he fires his bricks. I know that it is a different application but I thought that it might give the cement the volume necessary to give it insulative value.
I do have some stryafoam in the shipping container we use for storage. Didn't know if I could break it up and use that?
As usual thanks for any advice anyone can pass along and I hope everyone enjoys the photos.

SteveS