Steel Dome Oven

[Wiley]

Re: Steel Dome Oven

Cristo, Not as much progress as I would have liked. Our weather has been unusally wet for this time of year.

Since I last posted to this thread, I have created and attached the rebar armiture for holding the chicken wire around the entrance and if weather permits this weekend I will attach the stainless collar for the chimney. What I'm doing is making a separate shell unattached to the dome itself. Since there is considerable movement in expansion and contraction and I figure if the oven moves in its own space there is less likelyhood of cracking the outer dome. I will be attaching several layers of 1 " chicken wire over the whole of the dome, much like a ferrocement boat is constructed. Inside surface will be a layer of metal screen door screening. This screen will contain loose filled vermiculite between the outer layers of the dome insulation and the shell. Because there won't be someone to trowel against (as there is in ferro cement boat construction) the screen will hopefully serve that purpose. We shall see.

At present I have the outer shell constructed so that I fit such detail pieces as the collar, tack weld them in place remove the birdcage and weld the piece. Then set the birdcage back over the dome for final check that all is well. If so then I will remove the birdcage and set it up on saw horses so that I have access to both the inside and outside. I'll then attach the chicken wire and then sew on the screen. Then replace the birdcage of the dome and fix in place with large stainless steel staples to the vermicrete layer and stucco. A couple of days work and I should be applying the first layers of stucco. That's of course, if I can get the weather to cooperate.

I have a small group of friends coming over for pizza tomorrow but I'll be free to work on the oven on the weekend itself. The weatherman says the weekend will be fine with rain again the beginning of next week. The results (pizza mainly)so far have been quite acceptable and well received :-)
Wiley

[ovenrookie]

Re: Steel Dome Oven Update

Hi

You should check out the web link below, these guys make their clays ovens using a a mould that looks just like your pictures. Might find it useful? Good luck!!

Wood burning Pizza ovens ,Bushman Burners, African Pot House, Garden Patio Heaters & Chimeneas from Dingley Dell enterprises - How to make a Wood Burning Pizza oven

[Wiley]

Re: Steel Dome Oven

Ovenrookie, Interesting site! Believe it or not I was originally considering building my steel dome as a "plug" (they're calling it a "former") and casting a dome over it. In the end I desided that I only needed one WFO and that if I was interested in starting a business then that would/might be a way to go.

However, I need to start a new business like I need another hole in my head. I'm happily retired (this Halloween makes ten years!) and find I do not have the time to do all the other things I want to do.

Wiley

[waynebergman]

Re: Steel Dome Oven

Wow Wiley I am impressed. I like your style. You must be proud of the concept and the way it has all come together. Its looks just awesome ...wayne

[Wiley]

Re: Steel Dome Oven

Thank You, Wayne for the kind words. There are a few things I would do different but on the whole I am quite pleased with how my WFO has turned out so far.

I have the birdcage off the oven and am welding on some more support to change a bit the appearance of the entrance...give it the appearance of more thickness. Our weather is changing for a period of rain so I have moved the operation under cover of a car port. I should be tying chicken wire on tomorrow.

Garden Bay...is that the same Garden Bay that is part of Pender Harbour on the Sunshine Coast? My wife and I stopped there for a very pleasant couple of days going to and coming from Desolation Sound on our boat a few years back. Very beautiful location and looks like a great place to live!

bests,
Wiley

[Wiley]

Re: Steel Dome Oven

Update;
I worked under our carport during the past few days of rainy weather. Yesterday, during a break in the rain, my wife and I placed the almost complete birdcage back on the WFO. There is still some shaping of some of the hardware cloth near the front where it meets the granite countertop, but other than that I am fairly pleased and so glued it down and covered it up against last evenings rain...yet again :-(

The photos show the 1/2 inch hardware cloth which covers the rebar armiture also if you look closely you can see the window screening I wired to the inside of the armiture. This will serve two purposes: First it will contain the loose vermiculite which I will pour in via the still open top. This will be the last of the insulating material over the dome proper. Second it will support the inside of the first layer of stucco... basically give something to push against (once it is backfilled with the vermiculite). All in theory as usual.

Also in the front view you can see the stainless collar which is separate from the chimney and attached to the birdcage. The stucco will meet this and inside there is about a 3/4 inch gap all around between it and the chimney. All expansion should be confined to the dome and none transmitted to the shell. Again that's the idea, only time will tell if it works.

Wiley

[Wiley]

Re: Steel Dome Oven

Update for those who might be following:
Backfilled with vermiculite today. I used approximately 5 cu ft of vermiculite. If all goes well I will create the hardware cloth lid for the top of the dome tomorrow and start stuccoing :-)
Here's the photos:
Wiley

[Frances]

Re: Steel Dome Oven

Its looking really good!

I'm jusr glad I didn't see this before I did mine... your birdcage is so nice, its nearly a pity to cover it up with stucco.

[egalecki]

Re: Steel Dome Oven

No kidding. It's amazing. I just don't have the patience to get it that nice!

[Frances]

Re: Steel Dome Oven

I don't have the skill...

[Wiley]

Re: Steel Dome Oven

Elizabeth and Frances:
Thank you for the kind words :-) This project has sort of taken over my summer and many projects that were on this summer's "to do list" didn't even get started (much to my chagrin :-(

But on the bright side I think I see "the end of the beginning" as they say and might get this WFO weathered in before our rainy season usually sets in.

Here are some photos of the first coat/ scratch coat of stucco. The white material around the entrance and the chimney are closed cell foam which will be removed and the space they have created will be filled with high temperature silicone caulking. This is to provide for expansion of the heated dome.

Wiley

[egalecki]

Re: Steel Dome Oven

your scratch coat looks good. How thick is it?

[Wiley]

Re: Steel Dome Oven

Elizabeth,
The thickness varies. The vermiculite compressed as I pushed the stucco thru the hardware cloth as I expected. So in the areas between the "ribs" of rebar I think the thickness is around one half inch to five eights inch below the wire and 3/8 inch max above it. Where the rebar "ribs" would form a stiff point maybe one quarter inch at max. I first pushed a layer thru the hardware cloth and worked it back and forth to make sure there was a complete layer beneath the wires. Then I went back and dabbed on a thickness on top in order to form some roundness to the shape. I smoothed the surface to fairly round then ruined that shape by dragging the toothed trowel over the surface. Basically working one bay/rebar section at a time. There are a few places where there are some micro cracks from shrinkage of the mortar. Next coat will be thicker and will hopefully be uniform in thickness trying for something like one half inch (from the bottom of the toothed grouves) over the whole dome.

Basically this is my first project using stucco and so I'm improvising and making it up as I go. I read what I could before starting but most stucco is over a truly stiff surface like a wall. Ferro cement boats that I have seen done had two people working in unison, troweling one side against the other working together. But they had lots more metal (chicken wire) for the given thickness. Like I've heard said, "This is one of his early designs...and he sure learned alot from this one".

I will admit I am a bit concerned that the rebar will expand and contract with solar heating more that the rest and so form cracks over each rib with time. If that happens then some sort of elastic coating or paint will have to be used to make it waterproof.

There is a hollow sound when the surface is tapped sort of like tapping ones finger tip against a sheet rocked wall. I'm curious about how strong the finished structure will be. I have visions of one of my grandkids (who I think at times is half goat) scaling the dome playing mountaineer. And wondering just how much damage such an adventure would cause.
Wiley

[egalecki]

Re: Steel Dome Oven

I don't think mountain-climbing is a great idea, unfortunately. If there's a lot of give in the vermiculite layer there might not be enough support... but as far as cracking goes, there's a good elastomeric compound I get at Lowe's for repairing ceiling cracks when they're due to things I can't conquer, like roof trusses that flex in wind, etc. Look in the paint department, it's in a tube like caulk. It does a good job flexing and keeping the crack from coming back. It's paintable but not sandable, but you won't want to sand the stucco anyway, right?

If you're going to paint it, as well, you could use a light color to help keep the heat down... of course, judging from what a lot of people are doing lately, the step we take after building the wfo is building a pergola over it!

[Wiley]

Re: Steel Dome Oven

Just an update. This am I applied the second coat of stucco. One more, the color coat, and I'll be done with the stucco for the dome. Here's some pictures:
Wiley