36" Pompeii Build in the desert

[Sharkey]

Jim, when I looked for "in process" pics of the serpentine arch, all I could find was images of the completed ones. Reminded me of the old cartoon of the flow chart where "a miracle occurs" is written in the middle box. That is why I tried to document my arch the best I could, but don't' think I included a shot from the front of the arch right before I flipped my bricks to have the thick part on the inside and start the reverse curve. You can see from the pic below I reversed the curve after the fourth tapered bricks, which I think are at a little less than a 45 degree angle. Your arch bricks are all at a much steeper angle, which I believe will make it much harder to do a serpentine transition. I completed the hemispherical arches on the front and back of the vent, then mortared the serpentine bricks in using the two arches to anchor to and as a guide. If you decide to try to make this work we will all be watching with interest, and I'm here to help as much as I can and can post more pictures if you need.

I know it's a bit late for this build but I have a couple pics of the original serpentine arch in process. I had spent weeks looking at other builds trying to work out how to do the vent and everything looked too complicated. My brother helped with my build and we were discussing different options, dry stacking bricks to demonstrate our ideas when my brother had the light bulb moment. As soon as he turned that arch brick around the other way I knew it would work.

My build (along with Doug's at the same time) was the first build on Forno Bravo to use a tapered arch, but that was the way that Field Furnace (where both Doug and I bought our bricks) built their ovens and it seemed like the best way to go. The serpentine arch was an original idea and I am very pleased to see other builders using it. That is the great thing about this forum.

Link to my vent photos below:

[david s]

I’ve kept pretty silent re these brick flue galleries, but now offer my opinion. Building compound curves in brick requires some extensive complicated brickwork and if the solutions presented pretend to be structural and efficient, I can’t agree. All of these structures seem to break the basic bricklaying rules of tieing in corners and while I’m a big fan of doing what you can get away with, butt joints is not one I’d recommend. The requirement of the flue gallery is simply to extract the smoke away from the cook, many successful cob ovens have no chimney and consequently benefit from having no entry to work past. To end up with an entry that is almost as deep as the oven, as well as creating a heavy structure that acts as a heat sink drawing stored heat out of the oven chamber are two big disadvantages. In addition the difficulty in creating an inverted funnel form to extract the smoke efficiently, using brick units is a complex construction problem. Conversely a cast flue gallery can be simply formed and cast in situ, resulting in a thinner and lighter weight structure, allowing a far shallower entry that won’t act as a big heat sink. Compound curves are as easy to obtain as right angles and therefore result in a stronger structure. The only disadvantage I can think of is that the whole oven is not entirely created in brick. Although as castable refractory has largely replaced firebricks in industrial applications I can’t really see that’s a practical disadvantage.

[jim lofaro]

Thanks for the comments. Good thoughts for the folks to follow.

Poured the next hearth layer and exposed some aggregate to see how that would look as a finish. Added a 2 inch wide band of concrete patch at the bottom of the dome to keep water from soaking into the p-crete.

Built a few fires of paper, cardboard, twigs, wood scraps, and now a log as the fire burns down. Figure I will just idle at this stage for a while as our rainy season is about to start. May have to start over in September.

Framing up to pour a concrete counter top in the front of the heart using melamine.

Any advice is greatly appreciated.

[UtahBeehiver]

You will need to tarp the oven during you rainy season if you let the oven sit idle.

[jim lofaro]

Thanks Russell.

What is the best method for removing ash from the dome? I was thinking a stiff broom.

[UtahBeehiver]

I use an old garden hoe and a metal dust pan, nothin to high tech. When I am cooking and moving the coal around, I use a ss tube to blow the ashes off the cooking floor, some people flap the peel on the floor and the ash goes out the chimney, Gulf uses an old fire place bellow.

[Gulf]

I may be wrong but, did you mean "soot"? If so, you will soot it up and burn it off many times.

[jim lofaro]

Thanks all. I was actually looking for a method to clean the ash off the WFO cooking floor. The hoe method should work for me.

Finished framing up the counter top. All it needs is rebar. Poured a test section using 25 pounds of sand/gravel, 5 pounds Portland, 2 quarts 2 ounces of water, and 8 ounces of dry green oxide. A bit too green for us. Think I will try 2 ounces of the green oxide tomorrow.

[jim lofaro]

Set up 3 test block using a basic 25 pounds of aggregate and 5 pounds of Portland. I added 8 ounces of green oxide to one (left), 1 ounce green oxide to another (center), and no oxide to the last. Also added a little landscape glass to the top of each pour. Hit all 3 with a diamond cup wheel and the 100 grit diamond polish.

[jim lofaro]

Poured the counter top yesterday. Used 1/2 pound of 960 (green) oxide per 60 pound bag of the 5000 psi concrete mix. The plan is to wait 3 days and strip off the form.

[jim lofaro]

Any thoughts about stucco for the dome (acrylic versus traditional) or brands of stucco (La Habra, Quikrete)? This is a bit down the road for me but...

[jim lofaro]

Finished polishing the countertop. Started with the grinding cup and down to 3000 grit. Next steps are to stucco the base using quikrete base coat and restart the curing fires.

[jim lofaro]

Any cookware recommendations for the WFO? Is cast iron ok?

[Gulf]

Cast iron is ok for the lower temp cooks. Don't use cast iron at pizza temps like has been suggested for searing steaks. At the least those temps will burn the seasoning oil out of the pan. Those temps can also warp the skillet or pan.

For roasting and baking I have found that Graniteware type pots and broiler pans to be a real good fit for the WFO. They are cheap and easy to clean.

[JRPizza]

+1 for the Granite-ware. I bought some on Gulf's recommendation and although we occasionally use our cast iron, the Granite-ware is so much lighter which is really handy when sliding roasts into the oven, especially if the floor is a little too hot and you are placing the pan on bricks to keep the bottom from burning. You can also leave the Granite-ware soaking in the sink overnight without worrying about ruining the seasoning. We did recently "refurbish" some of our old cast iron pans by burning off 20+ years of accumulated/burned on oil. They came out looking like new and when the oven cooled a little we just re-coated them with oil and slid them back in to re-season.