Ferro Cement Pizza Oven

[cvdukes]

Re: Ferro Cement Pizza Oven

Geoff,
Looking forward to your posts on the progress. I think mine's been successful and just hope its not a fluke. If yours turns out okay, I think that we'll have a third ferro-cement pizza started in the spring. Our last party, we had an Italian lady here that really wants one in her backyard. Her husbands's not willing to go the price of brick or a pre-fab, so it'll be concrete if he decides to build her one. Since mine's been so experimental, he's not quite ready to take the plunge.
Actually, I haven't done a pig yet. In fact, I haven't used the big cold smoker oven for anything other than as a place to put flaming logs into if I have too many in the pizza oven when its time to cook... between the oyster roaster and the pizza oven, I've pretty much have satisfied all the cooking needs so far and have not expanded out to the full cooking capacity. Its oyster season again, so there'll be a couple of roasts soon. After that, I really do plan to do at least half a pig.
Thanks for the invite to Calif, but I rarely get out that way...I was in San Fran in July, but doubt that I'll have a return trip any time soon.

[gmhash]

Re: Ferro Cement Pizza Oven

Wow CV. Very impressive. I envision some incredible partys at your place. If you're ever out her (Nor. Calif.), let me know...we too do some pig roasts, though only manage to do one or two a year. Still cleaning up from this years - a couple of weeks ago. First year we did it in a Caja China. This year we did it on a rotisserie.

I'm tempted to copy your chiminea idea too. We have a fireplace next to the WFO currently, but it's the "leaning tower of Oaktown."

I will start a separate thread and post pics of my ferro cement adventures tomorrow. In short though, I poured mine in place, right side up. My opening is 20" wide. I'm not huge, but I'm not small either. All I can say is thank god for help from little brothers (literally and figuratively). My youngest brother has been helping and his shoulders were just narrow enough to get inside the opening to finish off the inside. Lucky me (to have him and to have avoided that part). I think I'll have to bring him back next weekend to do the liner though!

More tomorrow on a new thread "Ferro Cement Pizza Oven - Secondo".

-g

[Groves]

Re: Ferro Cement Pizza Oven

pics? Did you pour it upside down or no? Did you pour it "in place" as they say, or somewhere else to be moved later on site?

[cvdukes]

Re: Ferro Cement Pizza Oven

...

1) Any suggestions on how long to wait before I start firing the oven?

2) Any suggestions on how to fire it once I start (should I follow the same schedule as the brick ovens building it up over a week or so)?

3) In terms of a dome liner - I'm still playing with that. Do you think the ferro cement needs a protective liner?

Thanks for your help!

-Geoff

Geoff,

How long to wait: The longer that concrete can cure, the stronger it is. Nearly maximum strength is achieved by day 28... anything beyond that is not measurable.
My dome cured for ~9 months ...just because it was a project that got sat aside while I worked on other things.


How to fire it the first times: I kinda followed the brick oven suggestions, but have to admit that I pushed it on a lot faster schedule. Doesn't seem to affected my dome.

To line or not to line: That is the question! Honestly, I don't know if its really needed. Instinctively, I figure it can't hurt and may protect the ferrocement longer. My lining is 4 parts sharp sand, 1 part fireclay, 1 part powdered kaolin clay (high alumina content) & 1 part type N portland. My real concern was that the lining would delaminate, but haven't seen any evidence of it.

You see my other ferrocement project on here?
http://www.fornobravo.com/forum/f36/...ject-3464.html

[gmhash]

Re: Ferro Cement Pizza Oven

Craig,

You inspired me...after toying with different materials and methods (long ago determined I did not want to do a brick oven for this one), I stumbled upon this thread. And, last weekend, we "poured" the ferro cement for a 42" diameter dome (20" at highest point). It's been curing for 7 days now, under a substantial layer of damp drop clothes (in SF Bay Area where it's still in the 80's and very dry).

Next weekend, it's insulating blankets and vermicrete installation, and then hopefully a mortar or stucco layer before the rains come.

A couple of questions for you in light of your experience...

1) Any suggestions on how long to wait before I start firing the oven?

2) Any suggestions on how to fire it once I start (should I follow the same schedule as the brick ovens building it up over a week or so)?

3) In terms of a dome liner - I'm still playing with that. Do you think the ferro cement needs a protective liner?

Thanks for your help!

-Geoff

[cvdukes]

Re: Ferro Cement Pizza Oven

well, amazingly, everything on the boat is legal in this state ...plus one of those boat toters is the assistat DA here in the county, so I think I'm covered against the blue light special.

X Jim... same basic theory except we have a multistrand telephone cable that connects to our launch panel which we take out in a peddle boat with us. Our cable is only 30 feet long and the two boats end up drifting a lot closer no matter how well we put out anchors. We've talked about installing a blast shield to protect us but just haven't got that far yet. Last year we had a couple mortars misfire that got just a little too close, plus a little excitment with flaming debris in the back of the peddle boat. We've done this past 5 years and it gets bigger every year, a real neighborhood event... last year, I made new elctronic fuses so our sucess firing was up much higher than when we bought the fuses. the show last about 30 minutes and we pass the hat to defray the costs.

[RTflorida]

Re: Ferro Cement Pizza Oven

CVD, I hope you signed the waiver stating all those fireworks were for aggricutural work (scaring away birds from your crops)......wouldn't want to see the next series of pics with flashing lights and you in cuffs.

RT

[Xabia Jim]

Re: Ferro Cement Pizza Oven

Damn....looks like some nice homebrews too!

I've got a picture somewhere that looks like that boat.....we used phone wire and a battery to remotely set them off from shore....brings back memories.

[Inishta]

Re: Ferro Cement Pizza Oven

Now that's what I call 'pushing the boat out'....................

[cvdukes]

Re: Ferro Cement Pizza Oven

[QUOTE=Xabia Jim;28413]
Do you do July 4th pyrotechnics too?

QUOTE]

Jim,
How'd you know?

[Xabia Jim]

Re: Ferro Cement Pizza Oven

Innovations! You've really have quite a cooking complex!

Do you do July 4th pyrotechnics too?

ps...How do you avoid voids in your ferrocement?

[cvdukes]

Re: Ferro Cement Pizza Oven

Okay Craig, ferrocement dome lined with a custom refractory mixture.

Can you provide thickness of dome vs liner....no delamination?
and what you'd do differently now?

The ferrocement dome was about inch thick at the top but got thicker on the sides because the mortar was slumping...at extreme bottom, maybe 2 inches thick. Was trying to get more a uniform inside shape then really worried about thickness, but even then the inside of the ferrocement was rough. Think I posted this pic already but you see what I mean about the roughness. Also if you notice, I didn't get the hogwire covered with chicken wire on the inside of the throat into the oven ..My mortar didn't even cover the wire.
The earthenware clay ended up being maybe 3/8 inch...with lots of alligator cracking that exposed the underlying concrete.
Inside layer of fiberglass cement probably 1/4 inch thick .
Kaolin/fireclay/sand mix maybe 1/4 -3/8 inch (if that).
Once the dome was in place, poured a couple bags of regular concrete on top of it thinking I need more mass...not a uniform thickness becasue as everyone probably knows, just cant pour concrete on a curved shape.

Things to do differently:
Make the thing bigger! I'm limited to 1 pizza at a time and not the optimal location for the maintenance fire.
Make the thing round!... I've got a weird oval oblong shape going...sort of a cross between the bread tunnels and a true pizza oven.
Probably did not need the earthenware clay...but it got it out of my garage. If anything is the weak spot that I worry about, its the clay... but since the inside was so rough it may adhere terrifically for life...other theory is that it protects the ferro-cement but I dont think it really does.
Spend more time to make the opening arch symetrical because the door plug made of vermiculite concrete doesn't quite seal as good as it should.
Insulate better under the hearth floor... underneath the pizza oven is another oven for smoking foods... When the pizza oven is full max temp, get readings of around 100-120 on the steel plate roof of the smoker.
Get hold of one of those steel domes that WILEY or MINE have and use as an inside mold for the ferro-cement instead of trying to handpack the mortar in by myself.

[Xabia Jim]

Re: Ferro Cement Pizza Oven

Okay Craig, ferrocement dome lined with a custom refractory mixture.

Can you provide thickness of dome vs liner....no delamination?
and what you'd do differently now?

[Acoma]

Re: Ferro Cement Pizza Oven

CV, I am quite impressed. Pizza and bread look great. Try corn meal sprinkled on the peel for nice release next time.

[cvdukes]

Re: Ferro Cement Pizza Oven

Well, its been 4 weeks since I said that I was only 3 weeks out from finishing up. So a little update (and an explanation for the delay). And some pictures from yesterday.

If you recall , my project is a massive oven complex that includes a ferro cement pizza oven at the top and several other cooking chambers for full pig roasting and oyster roasts. The oyster roasting side contains a welded-metal framed stand built inside the brickwork. On top of the frame, there is about a 1/4 inch steel plate, covered over by a drum that will lift off... this is primarily for roasting oysters, but I can get a lot of other cooking in there if I want. When I did the brickwork, I mortared the metal stand in tightly...big mistake.
2 weeks ago I finished up the oyster side of the oven and decided to build a fire to make that the chimney serving everything other than the pizza would draw.

Good news is the big chimney works fine. Bad news is that I forgot to account for all the metal expanding as it got hot.

The longest dimension of metal in that side is about 45 inches.... at a 1000 degree temp rise, it expands 1/3 inch. Just enough to crack the bricks on both the front and back of the oyster cooker end.

As I mentioned before, I'm not much of a mason, so my brickwork isn't too pretty. Faced with cracking bricks and sloppy joints, I decided to cover the entire monster over with cement board followed by a healthy coating of fiberglass reinforced concrete as a stucco. So I added a few more weeks to the schedule. And the old elbow just doesn't do too well with smearing all the stucco... so having to take it slow. I should finish it all by the end of next week? at least that?s my new schedule.

Attached shows how it looks right now? halfway done with the stucco. And still have to come up with hinges for the doors. The doors are wood skins over a metal framework and I still have to add an insulating layer. Oh, and the roof is tin that will eventually be covered with vermiculite. It was in the plans to get done yesterday ?cause we hit some abnormal high temps, but just didn?t work out. Maybe my schedule will be 2 more weeks!

From left to right in the first picture: Drum cooker (oyster cooker). Two doors under it are the fire box for it. Fire will normally be built in the upper firebox and large coals will fall through to the bottom where they can be removed (to go to the pig cooker side if needed). The pig cooker is the larger door on the right with its fire box underneath. Small wooden plug door in-between the two large chambers is a little warming box?just big enough to reheat French bread during oyster nights. The pizza oven is the chamber at the top under the peak rook. Its cantilevered backward into the wasted space of the slope of the dam. Everything under the pizza oven vents out through the big chimney at the rear (center of pic)?Pizza oven has the smaller chimney on the front. Extending on past the oven to the right is concrete countertop with planned wood storage underneath

Second pic shows the pizza oven with 1000 degree heat glow?notice I still have all my construction tools close at hand. And, Yes, I really run that mssy of a work site.
Third pic: Pizza anyone? Actually my second try at these little devils. First time, I couldn?t get the dough to release from the peel? toppings all had more momentum so they went flying into the oven before the dough. Pizza upside-down pie is not the way to go! These are better because I built them on parchment paper which slides fine. The paper turns brown in about ? second and I had to move the pizzas off before the paper flared up?but the way to go for me.
Fourth pic: Two sourdough boules and some baguettes (supposedly pain de l?ancienne method?but haven?t mastered working with the really wet dough).

Enough for now.