gt40's Pompeii Oven 42" build log

[david s]

Re: gt40's Pompeii Oven 42" build log

Yeah I think you are right. But would an oven temp. on the outside of the bricks be enough to anneal the steel? I think you have to go pretty high to do that. This is a good question maybe only experience will be the answer.

[brickie in oz]

Re: gt40's Pompeii Oven 42" build log

Any prolonged soaking of heat above 600c will do it.

[david s]

Re: gt40's Pompeii Oven 42" build log

Then it should be ok. You won't get the outside of the bricks at the base to anything like that temp.

[gt40]

Re: gt40's Pompeii Oven 42" build log

But once steel expands and the temper is lost I thought it stays expanded?

I chose basic steel chain i.e. ? Low carbon chain

This is low carbon steel and not hardenable so it doesn't "temper" or harden.

It does however weaken while hot. The chain I chose has a working strength of over 1000 lbs/450 kg and breaking strength of over 3000 lbs/1350 kg. Even allowing for reduction of strength at pizza oven temps, it should be plenty strong. That is why I chose chain over steel cable.

[Lburou]

Re: gt40's Pompeii Oven 42" build log

FWIW, During my oven's last curing fire -after two hours of a big fire and without insulation- the top of the outside of the dome approached 300 F while the inside of the dome was 950 F.

Yeah I think you are right. But would an oven temp. on the outside of the bricks be enough to anneal the steel? I think you have to go pretty high to do that. This is a good question maybe only experience will be the answer.

[shuboyje]

Re: gt40's Pompeii Oven 42" build log

I have a question and a comment. First the comment.

I'll be demolishing my 30" low dome oven soon as I am building a 42" low dome to replace it as we speak. My old oven was "buttressed" with stainless cable so I will be able to chime in how it held up shortly. The oven was run at 1000F for hours at a time many many times, so should be a good indicator.

Now my question. What interior height did you decided on for the 48" oven? I just ask because as the dome is going in now it looks like it is gonna be pretty high. My 42" oven is going to have a 12.75" dome. For a 48" oven I think the rule of thumb put's it around 14".

[gt40]

Re: gt40's Pompeii Oven 42" build log

FWIW, During my oven's last curing fire -after two hours of a big fire and without insulation- the top of the outside of the dome approached 300 F while the inside of the dome was 950 F.

Thanks for the observation and also for posting that newbies guide to forno bravo. It was invaluable to me as I go and try to learn how to build this thing.

I have a question and a comment. First the comment.

I'll be demolishing my 30" low dome oven soon as I am building a 42" low dome to replace it as we speak. My old oven was "buttressed" with stainless cable so I will be able to chime in how it held up shortly. The oven was run at 1000F for hours at a time many many times, so should be a good indicator.

Now my question. What interior height did you decided on for the 48" oven? I just ask because as the dome is going in now it looks like it is gonna be pretty high. My 42" oven is going to have a 12.75" dome. For a 48" oven I think the rule of thumb put's it around 14".

Mine is going to be around 17"/43cm with the floor at 49"/124.5cm diameter.

Interesting you used stainless cable. I was going to use that first but ended up with the chain because it was so much cheaper than the 321 stainless cable I wanted to use. The stainless is much more resistant to the heat and holds strength at higher heat levels.

I spoke to my friend who is a mechanical engineer and the expected loads on the chain even at high pizza temps are not even close to the chains strength, even degraded by heat.

Anyway, Good luck with your next build, post some pics...

[gt40]

Re: gt40's Pompeii Oven 42" build log

Update:

Well, I got some time to work on the oven and it finally is starting to take shape. Here are a few pics:

top shot:


Inside shot:


I really need to clean things up at this point. I don't know how all the other ovens are so clean. I guess I will just go in and scrub followed by going in with a and mask and face shield and just grind it all clean. Part of me hopes when I finally get it done and up to full temp it will burn some of this stuff off. One can hope...

Final shot with the chain harness:



I will see if I can finish the dome tomorrow. Building these things is hard work!

Thanks for looking.

[ggoose]

Re: gt40's Pompeii Oven 42" build log

Your build is looking good gt40. The chain is a unique addition. Did you sink the bolts that supports the brackets all the way down into the hearth, or just into the vermicrete? Too bad you have to cover it with insulation; the chain would be a great conversation piece .

gene

[gt40]

Re: gt40's Pompeii Oven 42" build log

Your build is looking good gt40. The chain is a unique addition. Did you sink the bolts that supports the brackets all the way down into the hearth, or just into the vermicrete? Too bad you have to cover it with insulation; the chain would be a great conversation piece .

gene

Thank you for your comments. I wish I could show the chain! In answer to your question, I didn't use vermicrete.

The foundation is 4"/101.6 of high psi concrete. I sunk the anchors deep into the upper cement.

On top of that where the oven is I have a bed of 2.5"/63.5mm thick soft firebricks. Above the soft firebricks is 1"/25.4mm thick ceramic fiberboard insulation for a total of 3.5"/88.89mm of insulating material. Then I had them pour concrete up to the top of the insulating bricks so it was flush.

Here is a pic:



On another note, I had hoped to finish today but got sidetracked and only got to make one course. It is getting interesting at this point and I built my first row standing outside the oven compared with always standing inside.

[benguilford]

Re: gt40's Pompeii Oven 42" build log

I love what you've done there, particularly how you've set the first layer of insulating firebrick into the hearth slab. Very cool (no pun intended). Now wishing I had done the same!

[gt40]

Re: gt40's Pompeii Oven 42" build log

Update:

I am pleased to have finally finished building my first brick dome. I have to finish the chimney but the dome is very solid. I sat on top of it and is feels like it isn't going anywhere.

Finished oven dimensions:

49"/1244mm diameter floor

17.5"/444mm oven interior height

door opening: 18"/457mm x 11.5"/292mm tall.

3.5" soft firebrick/ceramic fiber board insulation under the floor

I really wished I had the patience to clean the inside better but at this point it is hard to work inside of there.

Here are a few pics:
top:


inside:


chimney top so far:



business end:


Thanks for looking

[ggoose]

Re: gt40's Pompeii Oven 42" build log

Great job gt40! I really like the chimney work (and the whole chain idea). Maybe you have a little grandchild/neighbor you could use pizza IOU's to bribe them to clean the inside for you . Worth a try. Looking forward to the rest of your build...

gene

[gt40]

Re: gt40's Pompeii Oven 42" build log

Great job gt40! I really like the chimney work (and the whole chain idea). Maybe you have a little grandchild/neighbor you could use pizza IOU's to bribe them to clean the inside for you . Worth a try. Looking forward to the rest of your build...

gene

Thanks for the encouragement


I went to do some more chimney work and found I have about 35 more bricks so I decided to make a flue channel go from the front to the top. I will build a little box on top of the dome where the chimney pipe will go.

Pics of the dry fit:






the roof of the channel will be ceramic fiber board...

[chidding]

Re: gt40's Pompeii Oven 42" build log

Wow thats different, but something im very keen to see the outcome. Dome looks amazing! keep us posted