Wfo build thread

[JConk007]

Yes there are different types of refractory. Many WFO Manufactures use different types of refractory cement.And in my opinion there is a nitcable difference   Earthstone is different from Forno B and is different from Mugniani and different from Pavesi... Rocky Mountain I believe uses a their own homemade blend? as does Stone Age Manufacturing  in their barrel oven  more porous type open graded like a 1/4" -3/8 stone coated in their own recipe and cast . I am sure you could concoct something. Are you wanting to buy floor tiles/ bricks for cooking  or just whip them up as well?   What size are you looking to achieve ? cooking floor, dome height....? Seems like a tremendous amount of effort when you can by the whole oven kit for like $1260 or something complete with fire brick.... and be cooking in 3 days the attached pic is $1800 complete. I have used it 3 times now and for the price its OK. If you have the time and energy thats another story I built mine but used a kit and took over  1 year!
But do get something its fun!
John

[Matthew]

Matt, so if we had 2 ovens that are the same in everyway except in the dome thickeness (2" vs 4"), same insulation, same oven & chimney opening, etc.   And given that both ovens are saturated with heat and had live fires going, that the thicker oven would burn less wood? 

  Chau

No, it would be negligible.  An additional 2" of ceramic blanket or castable insulation would make a significant difference in overall heat retention.

Matt

[Jackie Tran]

Good to know Matt.  After I read that John is in Wisconsin and wood is fairly inexpensive, I think a thicker dome, insulation, and a double enclosure is a good idea, especially for baking the next day.

Chau

[jgestner]

Hi Gang
I am thinking of casting my own oven shell but would likely use fire brick for the floor. I have looked at 2 different forms one a 36" round Plastic animal feeding/watering tub and the other being a larger plastic wheelbarrow for the casting. I think the 36" round tub could have a bit of a sand dome on top to get a near perfect Pompeii type shape.
I understand that proper thermal mass as well as insulation below and over the entire oven is a necessity.
I don't plan to build anything not up to decent quality and standards.
I am thinking something in the 38-40 inch interior would be nice and versatile.
To John/JConk I guess I would like to get in well under $1000.00 if possible for a start and then finish the outside housing a bit later.
Because of the long and wild winters we have here I am thinking more and more that I may like a complete enclosed Patio Room type structure for the oven. I can extend my season quite a bit with that.

John

[jgestner]

Hi Gang
Hey JConk You have a beautiful oven setup and patio kitchen setup. I think the pic w the blond prep girl under the umbrella is my favorite. I am guessing that by the graphical ad pic you included from your post to me that you have a barrel type oven interior. Over on the Forno Bravo site it's almost sacrilege to not build Pompeii round. Have you had any unhappiness with hot or cold spots? I have been thinking that the pompeii purists are a little too strong over there and that a quality build with good consideration of thermal mass and insulation should produce near equal results.
I think one of my goofy ideas to possibly use a rectangular wheelbarrow as an oven casting shape might freak many of them out.
Any thoughts or science will be appreciated.

Thanks as always
John

[JConk007]

My oven is an earthstone 90 in the build thread you can see the kit. I posted the barrel as my friend is selling theses as a reasonably priced alternaitve to dome oven and I have been cooking on it for demos and 1 party. You have me thinking? I have a plastic turtle sand box that might work well for your cast at least top Just do 1 or 2 rows of bricks straight up then this on top  I will grab a pic.
John

[Jet_deck]

John, did you see this one?  Looks like a good pattern for a home build and should bring you in at less than the $1000.

http://www.stovemaster.com/html_en/Semi_pre_cast_Brick_Ovens.html

[jgestner]

Hi Jet
Thanks for the link. I hadn't seen that site http://www.stovemaster.com/html_en/Semi_pre_cast_Brick_Ovens.html before. The prices though seem to all be over $2000.00 though. Canadian $1.00 = US $1.03109 and that is without base, insulation, and shipping.
The other thing is that I am still leaning towards a round Pompeii type build, even though my first wild idea was a rectangular plastic wheelbarrow for a casting form.

It's all just dreaming and research at this point so thanks for some more information to put into the scheming and calculations. As a 60 year old retiree with a wife that has not jumped into the dream quite yet, price will be a big consideration. Also the brutal North Central Wisconsin winters are going to need to be added to the equation as well.

Oh well
Thanks for any help you can provide.

John in Merrill, WI

[Jackie Tran]

John, Forno Bravo also sells a Pompeii oven kit that contains all of the materials needed I believe.   That might save you some time and effort in sourcing the materials.  Shipping maybe a deal breaker though.

http://www.fornobravo.com/store/Pompeii110-Oven-Kit-p-16315.html

chau

[jgestner]

Hi Gang
Hey JConk!
Here is a link to the turtle sandbox http://www.toysrus.com/product/index.jsp?productId=3480248 I like it! Cover with wet newspaper and start layering heatstop II or some other good refractory cement over it and Voila! A nice big oven in no time. It might be better to use the brick layers like you suggested for the sides of the oven and skip the turtle feet and head.
I like that better than the dog house igloo or the 36" animal water/feeder tub I was also looking at. The water/ feed tub is just a little smaller than I hoped for.

The precast kits are still an option but even at $1260 + shipping for the Forno Bravo Pompeii kit, that's about 3 times more than I am hoping to spend. I am probably dreaming and not very realistic though. Still thinking not doing at this point.

John in Merrill  

[JConk007]

Thats the one I have!! ! I was looking at it today actiually toook a few pics. I am thinking the top piece  would work well. especially for the low dome top ! My earthstone has a 1 piece top and i love it. Wheels are turning?
John

[Matthew]

The precast kits are still an option but even at $1260 + shipping for the Forno Bravo Pompeii kit, that's about 3 times more than I am hoping to spend. I am probably dreaming and not very realistic though. Still thinking not doing at this point.

John in Merrill  

I'm not sure what the prices are like were you live or how far you are in your budgeting but you will find that the insulation materials alone will cost you more than you are planning to spend for the whole oven.

Matt

[jgestner]

Hi Gang
I am still trying to imagineer a less expensive solution for a WFO. If the cost of materials is too high I can scale back in size to cut a bit off the total price. I expect though, that route will provide diminshed returns if pushed too far.

How about a form with an inner ring about 38-40 inches diameter and 8-12 inches tall and an outer ring 3-4 inches bigger to cast the non-insulating refractory cement for the oven sidewalls and then some kind of appropriately sized domed form, turtle or no turtle, for the oven top. Normal firebrick or cast non-insulating refractory cement for the floor.

Proper base size, strength, and insulating qualities. Then a metal stud enclosure with cement board cladding and metal roof. And just fill the enclosure around the oven with vermiculite. Here is a reasonably priced vermiculite 4 cubic foot for $24.00 http://www.greenhousemegastore.com/product/vermiculite-4-cubic-foot-bag/soil-growing-medium?utm_source=MSN&utm_medium=cpc&utm_term=4502405230&utm_content=292342645&utm_campaign=Greenhouse_Supplies

I would think that filling the entire enclosure cavity around the oven could ammount to appropriate insulation.

Just a thought

John in Merrill

[jgestner]

Hi Gang
I was just looking through our local weekly Menards sale flyer. They had rolls of some kind of composite lawn edging. It was only $.99 for 12 feet. This edging was only 3 and 1/2 inches tall. At Amazon there was some 5 inch stuff for a little more money. Would it be unreasonable to think that stuff could be used for inside and outside casting forms for oven walls? I might think that stacking a couple of these 5 inch rings would be even easier weightwise over trying to cast all the side walls in one piece.
I think I can find something like this and get nice smooth inside and outside walls without too much fuss.

Still thinking about the dome. maybe a sand form with newspaper would be easy enough if I can't locate a suitable prebuilt form.  

John in Merrill

[shuboyje]

If you are looking for cheap here are a few pointers.

Insulate with perlcrete and zonolite.  They are cheaper them mineral wool, ceramic fiber and vermiculite.  You should be able to find 4 cu. ft. of Perlite for $20 or under at garden suppliers locally.  I found zonolite at a block supplkier for $12 per 4 cu. ft. .  Zonolite is silicon coated vermiculite and is only suitable for loose fill, it will not mix into a insulating concrete. When making perlcrete mix it 6:1 with portland cement.  Figure out how many cu. ft. of finished perlcrete you need and double it and buy that much loose perlite.  It shrinks nearly 50% when mixed into perlcrete.  4 inches under the oven is suitable and then loose fill around the oven with atleast 6 inches of zonolite. 

Use brick and homebrew mortar instead of castable.  The cheapest castable is way more expensive then firebrick and home brew mortar. Use full size bricks cut into thirds instead of half to save more money.  This will yield 3 inches of thermal mass which is plenty for a backyard oven(I say this from experience).  Home brew mortar is 3 parts the finest sand you can get your hands on, 1 part portland cement, 1 part lime, and 1 part fireclay.  If you want to be really cheap pre cut all your bricks into thirds and then use the dust in place of fireclay. 

You can build a suitable oven cheaply if you don't need a fancy looking stone enclosure and you try and follow these guidelines.     

[JConk007]

John,
 I found 2 CF bags and I think I used 8 of them think they were $25 each as well? filled the whole cavity with this mix just dusted with conc and slight bit water. I have   no insulatinf blanket over the dome,works perfect cool to the touch with dome at 1000 for 1 hr. ! I have 0 cracks just 1 little chip by joint after many firings?
John

[jgestner]

HI John JC
John here too.

I am getting pumped with your announcement that you had no need to buy fancy insulating blankets or insulating refractory cement. I think lots of people should hear that in this forum. There still seems to be too much advise that helps you bake ribs or beef roasts 3 days after making a pizza on the same burn.

I totally understand doing that, but if I want burn a pizza one day and go out for steak the next, and go out for chinese the next day,  and all of my firing wood is free on my own property, should I really need to consider all of the thickness issue of oven mass, insulating mass, bla bla bla?

 Yes, I understand that a big part of this oven style is creating a fire for floor heat  and in oven heat, and then removing or brushing aside that fire for cooking. I understand fully that under floor insulation makes sense to what ever level is acceptable. But if heat retention for 3 day cooks is not the biggest requirement, can we back down on some things that are real important for that 3rd day roast, but not for me?

In favor of cost considerations...... oh I'm sorry to be trying to start the cheapness campaign. My wife said fogettaboutit more than once already and she has no clue about a kit cost from forno pompeii of $1200.00 plus shipping.

I guess I may be trying to perfect my free from old parts LBE for a while.

Thanks for trying to help me, but maybe I am beyond help.

John in Merrill