Preparing for steel oven build.

[Wiley]

Re: Preparing for steel oven build.

Scarnucci
Where I come from Quikcrete is a mix that when water is added makes concrete. It has gravel and sand and cement.

You do not have to use refractory (calcium aluminate) cement when mixing vermicrete, regular portland type 2 will work just fine. Probably portland type one or even "plastic" cement (which is plastic only in consistancy/flexibility not made of plastic) would probably work as well. There are a couple of good threads concerning how to mix so I would advise checking the archives. RTflorida (if memory serves) had a procedure for mixing and placing which allowed for high insulation with little cement and lots of vermicrete (9 or 10 to 1 vermicrete to cement ratios are possible). The threads are a couple or three years ago.

Hope this helps,
Wiley

[TapRackFire]

Re: Preparing for steel oven build.

Scarnucci,

How did your oven turn out? I have poured my foundation and liked your version for a dome.

[scarnucci]

Re: Preparing for steel oven build.

Pizza fiends,

A cheating wife and a divorce and a topsy turvey 2012 put my build on ice, but never out of mind.

If it is in your heart, in your blood, if it is your passion, you can find a way. So, here I am, keeping the dream alive.

The last photos I showed were the bricks directly on top of the insulation. During one road trip to and from the welder, I had the unpleasant experience of the weight of the dome on some bricks digging trenches into the insulation. Ive attached some photos of the tray I had built to lay the bricks into, and then of course the dome rests on top.

As you can hopefully see, there remains a gap of about the width of a two by four all the way around the tray. I added some brackets to the dome where I have eight inch, 5/8ths bolts and nuts going up through the trailer frame, through the brick frame, through the fire brick, and holding the dome in place. It seems to be fairly sturdy. Ill see how it holds up after a few road trips.

[scarnucci]

Re: Preparing for steel oven build.

The above pictures also show part of the frame for the "hut" that will enclose the dome. During test fires I just had the fire inside an uncovered dome. While the temps on the underside of the trailer remained warm to the touch, the heat pouring out of the un-insulated top was off the charts. I could just see waves and waves of energy escaping into the air. The pizza showed that as well. Even though my bottoms and crust was getting done, the top was never cooking at the same pace, and I had to finish them in my oven's broiler.

[scarnucci]

Re: Preparing for steel oven build.

Having read another thread about turning a Webber grill into a mini pizza oven, I saw suggestions of welding a steel plate above the pies to reflect the heat back downwards. I decided to have a shelf of angle iron welded inside the dome. The shelf is sized so that I can insert about 5 fire bricks about 12 to 18 inches (I never measured) above the cooking surface. Once the oven has heated, these ceiling bricks are nearly as hot as the floor bricks. As I cook and rotate and finish the bottom of the pie, I can lift the pizza up, and char and cook the top of the pizza with the heat radiating from the ceiling blocks. I trust you can see the difference.

also, I wrapped the dome in Superwool. My goodness that is great stuff. Whereas before the insulating wool, I would have lost a limb attempting to touch the super heated steel dome, the wool insulates the dome wonderfully, and I can touch the wool with no problem. Having seen first hand how much intense heat was lost to the atmosphere before the wool, I am confident that all that heat is now being redirected back into the floor brick layer.

While I did not time my heat up and cool down times last weekend, I did monitor the brick layer at over 800 degrees. I am unconvinced of the necessity of a thermal refractory layer around the dome. I might just go buy another roll of superwool, wrap the hell out of the dome, then close it all off with my metal walled hut. I'll see if the temps hold up during long fires with many pies being cooked before I make up my mind. Good thing is, I can always go back and re-engineer at this point. Just have to remove sides and tweak as necessary.

Input appreciated!

[Wiley]

Re: Preparing for steel oven build.

Scarnucci,

Interesting report back. Before deciding not to go without the refractory layer you might try a overnight bake of something like a pork shoulder. We commonly will have a shoulder prepared to use the residual heat for an overnight bake. Typically we pull the fire to the other side of the WFO and place some fire bricks on edge between the fire and the future location of the roaster containing the shoulder. After the WFO has cooled off a bit and the bricks have absorbed some of the heat. We toss some beer soaked wood chips nested in aluminum foil on the coals. We then slide the roaster in (obviously with lid off) and with the door ajar smoke the pork for about 30 minutes. Then we rake the coals completely out, cover the roaster (good time to pour half a beer into the bottom), and close up the WFO for the night. Next morning perfect pulled pork.

A good portion (almost all) is done with residual heat. It would be interesting if you can get similar results without the refractory. Of course if you are not contemplating using your WFO for anything but pizza, then residual heat cooking is of little concern.

Sorry about the rough year.

Bests,
Wiley

[scarnucci]

Re: Preparing for steel oven build.

[scarnucci]

Re: Preparing for steel oven build.

[LittleBritaly]

Re: Preparing for steel oven build.

I build,sell and hire ovens in the UK,I've also built ovens on trailers.

My ovens are very similar to yours, I don't use a steel shell I use fibreglass, I also don't use firebrick anywhere, I use silicon carbide for flooring (these are lightweight ovens, the lightest being 17kg, that's about 35lbs).


My advice, turn the shell upside down, put the insulation you've got on the outside, inside, then cover in a thin layer of refractory.

Leave for a couple of days, then turn over and put back in place.

I help the drying process by using candles to add some gentle heat and gradually increase to a low flamed gas poker.

I typically use maybe 1/4 of an inch on Pizza ovens and it works really well.

Your refractory will eventually crack if you're travelling any distance, just carry a dry mix of refractory.

[scarnucci]

Re: Preparing for steel oven build.

The walls and roof are going up with the insulation and dome more or less as is. I have 2 inches of superwool held down with a welding blanket. Ive had temps of 900 degrees with pies cooked in 90 seconds. Zero refractory. Granted. Ive only done quick cooks of 6 pies at a crack. Some weekend Ill monitor temps and timelines. Current heat mass is totally sufficient for dinners at home.

[LittleBritaly]

Re: Preparing for steel oven build.

Good to hear you don't think you'll require refractory, I'm very interested in finding out how your oven performs, I've been considering building some ovens similar to this (no refractory).

I've just built a barrel oven that has a steel shell which is lined with insulation and an in-house refractory, it has a choice of floors (silicon carbide, firebrick or tiles) and I was very surprised to find it worked at least as well as my other ovens.

Good luck with your build

[scarnucci]

Re: Preparing for steel oven build.





I worked off and on over the course of a couple of years on this thing.
Trying to recall my costs.
Trailer was around $425
I think tank cost me $250
Fabricating the frame and brick tray was probably all in all around $1000
Maybe about $100 in bricks.
Insulation $150
Buying material to build the metal hut and the labor to put it up was probably another $200
Probably some other odds and ends and costs that Ive forgotten about but I guesstimate around $2500 from start to finish.

I'll probably throw a couple hundred more into figuring out what I want to do with the area under the oven. I might put some metal mesh and store wood under it. Might add a pickup truck type storage box to keep some tools or a set of jack stands. Any input would be appreciated.

[scarnucci]

Re: Preparing for steel oven build.

[jinsko]

Re: Preparing for steel oven build.

Cool oven, Scarnucci. I'm wondering about heat retention for your oven. Does it keep enough heat to do any cooking other than pizzas, like overnight bbq or something?

Also, good to see another Hoosier around here (though I'm in Michigan now).

-Jeff

[scarnucci]

Re: Preparing for steel oven build.

This year Ive cooked pizzas for a couple of large gatherings. In the past month Ive done two events and output about 30 pizzas over the course of about 4 or 5 hours. I have no experience with a refractory oven so I cant really compare my heat retention during use to others. For my purposes, I can maintain cooking temps around 650 with little trouble for the duration of my events. Honestly, since I typically cook my pies, clean up, and hit the road, I dont have much interest in keeping temps high for hours on end. When I do BBQ or smoke bacon, I have a dedicated smoker at home for that.