I'm getting closer to my Dome!

[brickie in oz]

Re: I'm getting closer to my Dome!

At the low end of the compressive strength cart it says 80 psi.
Assuming each brick weighs 4lb then you can load 20 bricks per square inch.

Ill say its fine then.

If it were me Id make a sample and do just that, load as many bricks on a small sample and see when it gives.

[Aegis]

Re: I'm getting closer to my Dome!

At the low end of the compressive strength cart it says 80 psi.
Assuming each brick weighs 4lb then you can load 20 bricks per square inch.

Ill say its fine then.

If it were me Id make a sample and do just that, load as many bricks on a small sample and see when it gives.

A sample and a test with materials I have right at hand! Too practical and it uses too much common sense! I hate to do it for those reasons but I have no choice! lol Thanks for the great advice! I'll post a pic before and after failure!
Thanks Al
John

[Aegis]

Re: I'm getting closer to my Dome!

Latest up date.... Working on the outer arch I mistakenly put two bricks upside down! OMG what was I thinking??????????????????
I tore the arch down and started over. Here are a couple of pics of the arch, it is still not finished! Glad I worked on the cement block veneer, no telling what else I would have messed up! Look at the last pic --- no cement!
John

[Aegis]

Re: I'm getting closer to my Dome!

Well I have been working on the vent/flue and so far so good. I have a question on the clay flue liner I am using. Do I mortar it to the base firebricks? I have read not to have bricks from the chimney touch the flue (except for a few small points of mortar). I do not know the expansion differences between firebrick and clay flue. The flue is 8*8" and I have copied the split it on an angle and make a funnel technique that I have seen on several beautiful ovens. Mortar or not to mortar the flue to the base????

[dmun]

Re: I'm getting closer to my Dome!

I mortared mine. That's how fireplaces are built, with the flue tiles joined with heatstop. It's mostly to prevent flue gas leakage. I wouldn't be surprised by a hairline crack there.

[Evets]

Re: I'm getting closer to my Dome!

Before I switched to the Duravent chimney, I had two 2' sections of clay pipe. It didn't take long before both sections cracked down the middle, lengthwise, separated from each other and also from the vent. And that was using Heatstop 50 mortar. From where you are now, I'd seriously consider the Duravent or a similar system. On the other hand, if you use clay and enclose it properly in a brick chase with an airspace around it, it would likely be fine. Personally, I just didn't want to deal with all the extra brickwork. On the other other hand, the extra brickwork can be a beautiful thing, if you plan for it. Pardon my rambling.

[Aegis]

Re: I'm getting closer to my Dome!

Well after much self debate I opted to stay with the refractory flue. I am hoping to test the flue with curing fires and then some pizza parties, before I build the chimney around it. If it survives several hot fires, I am hoping it will last as long as the oven lasts. I know the oven would outlast the duravent, but maybe not the clay flue. At least that's my story, and I'm sticking to it!
John
Added these pics... I have been looking for pics of chimney base. I did see the GREAT build of dmun and that gorgeous hip roof and dual flue. Wow is all I have to say! What an oven and a half!

[PizzaIdiot]

Re: I'm getting closer to my Dome!

You oven is looking great!

I was wondering how long you can wait before cleaning the mortar on the inside of the dome before it gets too hard to clean?
Once it's dry/cured, what does one use to clean the inside?

Thanks and keep the pictures coming,
Jeff

[Aegis]

Re: I'm getting closer to my Dome!

You oven is looking great!

I was wondering how long you can wait before cleaning the mortar on the inside of the dome before it gets too hard to clean?
Once it's dry/cured, what does one use to clean the inside?

Thanks and keep the pictures coming,
Jeff

Hi Jeff,
I didn't use forms to hold the bricks in place. (except for the last ring/keystone, used a ball for that) Without forms I usually let the bricks set for 15 minutes and then used a wet sponge and wiped them clean. VERY easy to do at that point. Some runs from the watery sponge could get wiped out a little later with a damp sponge. If the mortar starts getting hard then the trowel could be used with a wiping of the sponge again. After it is hardened then the dreaded grinder, with all its dust and vibrations!
Thanks for the compliment on the oven, I tried to come close to prior builds but my stomach wouldn't let me take the extra time to do it better.

[Aegis]

Re: I'm getting closer to my Dome!

This is my planned thermal break for the chimney. Firebick, topped with foamglas then chimney brick on top of that. The chimney will be a total of five feet high from that point up.
Ok, I stacked up 97 pavers @ 6 lbs. per paver for a total load of 582 lbs. That is a five foot high chimney. The foot print of my stack is 16"*8"= 128 sq. inches. For a 4.54 psi. load The foamglas is rated for a compressive load of 90 psi I hope my calculations are correct! Please someone let me know if this is correct or I am better off stacking the brick on top of the firebrick for strength!
Thanks in Advance
John

[ggoose]

Re: I'm getting closer to my Dome!

John,

Your thermal design seems sound, but if I understand correctly, you are going to stack over 500 pounds of brick over your entry arch? Unless you have butressed it and not shown us I would hesitate to place so much weight on it. Perhaps a few firebrick columns against the sides of the arch, or some angle brackets to prevent blowout. I would hate to see all of that work collapse...
Just a thought.

gene

[Aegis]

Re: I'm getting closer to my Dome!

John,

Your thermal design seems sound, but if I understand correctly, you are going to stack over 500 pounds of brick over your entry arch? Unless you have butressed it and not shown us I would hesitate to place so much weight on it. Perhaps a few firebrick columns against the sides of the arch, or some angle brackets to prevent blowout. I would hate to see all of that work collapse...
Just a thought.

gene

Hi Gene,
Of course I haven't buttressed anything! It did cross my mind that was a little too much weight for the arches. I was thinking if I had to do something like that, then the stud walls I am planning on using will give lateral support to the front arch and I will bring that back towards the rear arch and do the same. Then over the vent tie them together, I may possibly use unistrut for the "bridge" I have gone through many threads without seeing many brick chimney supports. Dmun and another which escapes me at the moment are two that I have seen.
Thanks for the reminder, I needed that!

John

[Aegis]

Re: I'm getting closer to my Dome!

Still trying to figure the best way to make the chimney. I have seen many designs with duravent, either left exposed or encolsed in cement board and then veneered with stone, brick etc. I have also seen short chimneys on top of an igloo build (Les's oven come to mind, great job!) But I haven't seen a tall (relatively speaking, 5 feet of added brick work) chimney built on the vent. I am VERY worried there is a good reason for this lack of construction!
I am at the present tending towards using 4 inch. cement block up until the roof line and then do a small brick chimney above the roof.
On another note: the front archway and entrance question. I have seen many decorative (may I add beautifully decorative arches) in front of the firebrick arch. I cannot make out from the pics I've seen if the decorative arch touches the hot firebrick arch. Is there an air gap between the two? If so how much? Just so that they aren't touching?
I am starting to "cure" the oven, even though I do not have the chimney figured out as of yet. I put a work light inside and let it on over night. I temporarily connected the tc meter to the dome brick tc and it read 90 degrees @ 9am out side temp was 68 degrees. So I believe the light is heating up something. Unfortunately it is going to be raining most of today so I hae the oven tarped. Not much evaportation going on today.
The work lights are two halogens with two brightness setting(read heat output) so I will use them all week until I get some time off work and can tend a fire all day.
As Always thanks for all the comments, criticisms, and most of all with your patience and help!
Thanks
John

[Aegis]

Re: I'm getting closer to my Dome!

Today I installed the first piece of refactory flue and worked on the facade a bit. Putting in a flat arch across the front opening. I am also starting to cure the oven with a couple of halogen lights inside the oven and a wooden door mostly blocking the opening. I got to try out my toy, semi-homemade thermocouple meter. Outside temp. read 77 degrees and the dome temp read 112 degrees F I haven't hooked up the other couples as of yet, so other temps around the oven are still unknown at this point.

I am still hoping someone has some words of wisdom on the chimney indecsion. In other words Help!

Thanks
John

[BriggsARNP]

Re: I'm getting closer to my Dome!

I haven't built my oven yet but I asked the question once and had some feedback. If you want to check out the thread I will attempt to add it. http://www.fornobravo.com/forum/f8/i...ing-16044.html