Mobile 36" Oven in Oregon

[Salty]

First of all...A mighty "Thank You" to all that have made this trek before me. I have read enough of these posts for my wife to think I have a serious addiction.

Anyway...Here is my plan/situation. My family is about to be expanding and we live in an old house that might not be where we are in 5 years or so, but as all of you can understand, a WFO waits for no man. Hence, the dilemma, how do I build an oven that I don't have to leave for the next owner to enjoy.

Well, I am lucky enough to work at a manufacturer with some hearty metal working abilities. My first step was having the guys in the shop build a 42" x 48" fully welding cart using 2" x 2" steel tubing. Luckily, there were some industrial casters/wheels floating around the shop that are rated 1,200lbs each. A real find, given that buying these new would set me back over $400.

So that's where I am at now. My plan is to have them also fabricated a 14 gage steel pan that will be 52" x 58" x 5.5" high. This will serve as my hearth for the oven. My thought is that I will weld some rebar about 1" off the base of the pan in order to reinforce it before I pour about 1.5" of concrete into the pan. On top of this, I will pour 4" of Vermicrete to serve as insulation. Do you think this will be strong enough to serve as my base? Should I just splurge and buy the insulating foam instead?

I'll post pictures of my cart in the next day or so, but I would really appreciate any advice that people have to offer on what direction I should head with my build. Can't wait to document my process for all of you.

[Salty]

Re: Mobile 36" Oven in Oregon

It has been a while...

My pizza oven had to take a back seat to my beautiful new daughter that was born on the "Apocalypse"...at least for a while.

Anyway, I posted pictures of creating the "hearth" in the shop at my work. Basically, it is just a heavy gauge pan that has been welded together, then I ran some c channel across rather than using rebar. I am hoping it will work.

As for the concrete...that was a new experience for me...especially when it is freezing outside. I rented a little electric mixer and ran about 1.5 bags at a time. Luckily my shop at home is heated, but mixing concrete indoors is not something I ever anticipated doing. In total, I have 7 60lb bags on the table to leave me just under 2" of thickness. Are there any concrete experts out there that know the implications of having concrete too wet...am I in trouble?

I also included a picture of my ceramic blanket sitting on top of my sails...they used to have a room in the house, but but the baby kicked me out of my storage room...ha.

[Coloradoredusa]

Re: Mobile 36" Oven in Oregon

Hi Salty..I think that you should get the Ceramic Fiber Board.. I got mine from Slyline Components out of Arizona.. It was 100 $ for 3 24" x 36" pieces, including shipping..you can just take it out of the box.. no more mixing Vermiculite and Portland.. except for when you start the insulating layer after the dome is finished.. that's what I did!

Good Luck!

[Salty]

Re: Mobile 36" Oven in Oregon

so...I sucked it up and bought another 1.5" of CalSil to add to my floor insulation. I was reading the forum posting about what people would change if they did it again and way too many people said "add more floor insulation" for me to ignore it (sorry Al, better safe than sorry). I sourced it from a different location this time. Less than a mile from my work and the 1' x 3' x 1.5" boards were $19 each.

Also, I noticed they had boxes upon boxes of ceramic blanket lined up so I asked the guy if they might have some end cuts floating around that I could purchase. He laughed and said they had dumpsters full of the stuff. He said if I come back when his boss is around they will fill my truck with blanket scraps at no charge. Not too shabby.

Also, anybody know anything about transite? He said all the pizza shops around town buy it for their pizza stone. Its expensive stuff but he had a bunch of end cuts of that also.

[david s]

Re: Mobile 36" Oven in Oregon

" Are there any concrete experts out there that know the implications of having concrete too wet...am I in trouble?"

Concrete that contains too much water will be weaker, it is a common error in an effort to get suitable fluidity. Too late now,but you should have used a superplasticiser so you can use less water.As your slab is only 2" thick this could be an issue, but don't know how much strength you'll get from the sheet steel on the bottom, the sides and the reinforcing you put in, but I guess you'll be ok.If it were mine I think I'd be adding some steel diagonals, perhaps from the centre of the underside of the steel plate to halfway down at least two legs. Alternatively a horizontal rail welded underneath that supports the centre.

[Salty]

Re: Mobile 36" Oven in Oregon

Great call on the reinforcements. My other thought was to add a full sheet of steel or concrete board to each side of the cart. That way I could be reinforcing it and cleaning up the lines a little bit.

I have to admit, I am still worried about how heavy this is going to be.

[Cheesesteak]

Re: Mobile 36" Oven in Oregon

Hmmmm . . . . that concrete does look pretty wet. If it was a bit thicker - I wouldn't worry as much - but at less than 2" - I would worry about its strength.

More importantly - I worry about the thickness of the concrete where your reinforcing bars are located. Generally - you want a minimum of 1.5" from the edge of a piece of rebar to the edge of concrete. Anything less could cause splitting of the concrete. If you're less than 2" with your slab - I would think your weakest points will be where your reinforcing steel is (that is - so long as I understand how the concrete was poured around the reinforcing you have).

If I'm not mistaken - you can actually see a shadow of the reinforcing channel in the concrete slab (last pic - left hand side).

With a 2" slab - I wouldn't put anything more than WWF for reinforcing. I might be inclined to break it out while it's still green and redo it. But - that's just me . . .

[Salty]

Re: Mobile 36" Oven in Oregon

" I might be inclined to break it out while it's still green and redo it."

You're killing me cheesesteak....those are not the words I wanted to hear.

Does it make any difference that I used sand/topping mix vs. regular concrete? I will admit, I wish I would have just bought some rebar and welded it in for reinforcement, but it was Saturday morning and I was at work...and it was free.

With the steel pan there, my primary concern is compression strength, so I think I will be ok...

Who knew pizza could be so stressful.

[Cheesesteak]

Re: Mobile 36" Oven in Oregon

" I might be inclined to break it out while it's still green and redo it."

You're killing me cheesesteak....those are not the words I wanted to hear.

Does it make any difference that I used sand/topping mix vs. regular concrete? I will admit, I wish I would have just bought some rebar and welded it in for reinforcement, but it was Saturday morning and I was at work...and it was free.

With the steel pan there, my primary concern is compression strength, so I think I will be ok...

Who knew pizza could be so stressful.

What is "sand/topping mix"? Is that something like a grout? the difference between sand mixes and more standard concrete is (in part) aggregate size. The thicker the slab - the larger the aggregate should be to provide proper strength. Anything more than 1 1/2" or so and I'd want to use a concrete mix - and not just something like a sanded grout.

Not sure if that's what your referring to . . .

The steel you have might be fine to hold the oven without any concrete - so you might be fine anyway. But - if you're relying on the concrete slab for any structural strength - I would be a little concerned.

With that said - I'd have to see how the legs are attached to the metal pan to see if the concrete is really providing any structural support at all. It might be that the concrete is really only serving as a surface to put the insulated board on . . .

Is your metal pan holding up all the weight of the concrete - or is the weight transferred to the legs?

[Cheesesteak]

Re: Mobile 36" Oven in Oregon

Salty - what did you end up doing with the oven?

[Salty]

Re: Mobile 36" Oven in Oregon

Hey all... I have been squeezing in work on my oven whenever I can oven the last few weeks, but needless to say, this new baby sure is time consuming.

[AaronTheGeek]

Re: Mobile 36" Oven in Oregon

Interesting saw there. Is that like a lathe with a table saw attachment?

~Aaron

[ATK406]

Re: Mobile 36" Oven in Oregon

Nice start on your oven. What are you planning to do with your inner arch? Are you planning to bevel the arch to match the angle of the dome (recommended) or "hang the dome" on a plainer arch?

BTW..That's good beer...but not quite as good as the Bells Hopslam we get out here.

Good Luck,
AT