#11  
Old 05-24-2006, 02:00 PM
Journeyman
 
Join Date: Apr 2005
Location: Brazil
Posts: 306
Default

Drake:

The oven thermal mass is a compromise question. This is a point that was discussed in past threads. Resuming it, less thermal mass, less temperature storage, less residual baking time. It could be no problem if you are thinking in baking pizzas (always with fired oven) eventually, or a single batch of bread.
Will be if you think higher !
Like you pointed, the concrete in slab has no function in retaining heat.
If you laid side bricks in your oven hearth, you could have 2 inches of thermal mass in it. Remembering that heat could be transmitted by radiation, convection and conduction, be careful to maintain the same thermal mass in the dome or barrel bay to equilibrated baking.

Luis
Reply With Quote
  #12  
Old 05-24-2006, 02:40 PM
DrakeRemoray's Avatar
Il Pizzaiolo
 
Join Date: Mar 2006
Location: Littleton, CO
Posts: 1,211
Default

Thanks for the help Luis, Both Fio and I are using the "new" design which calls for resting the hearth bricks directly on the insulating layer.

My question (and Fio's) about the first few rings of dome brick still stands.

Luis mortared his first dome ring on the outside only.
Mike mortared his first dome ring to the floor.

Do most people mortar the first ring to the floor or just put mortar on the outside of the dome?
Drake

Last edited by DrakeRemoray; 05-24-2006 at 02:44 PM.
Reply With Quote
  #13  
Old 05-24-2006, 03:51 PM
Les's Avatar
Les Les is offline
Il Pizzaiolo
 
Join Date: Sep 2005
Location: Carson City, NV
Posts: 2,858
Default

Luis,

Are the red bricks on your dome curved or is that the camera playing tricks on my eyes? Is it posible for you to post a picture of the top of your dome? I would like to see how you capped off the brick. Your oven looks great!

Les...
Reply With Quote
  #14  
Old 05-24-2006, 04:25 PM
CanuckJim's Avatar
Il Pizzaiolo
 
Join Date: Jan 2006
Location: Prince Albert, Ontario, Canada
Posts: 1,480
Default Still Stands

Drake,

Haven't built a pizza oven, but from a mason's point of view, I would definitely mortar down the first course of brick. Sure, the cladding will provide lateral strength, but insurance is a good thing, long as the premiums ain't too high.

When the brick begin to lean, butter the mortar in a wedge. If the angle's extreme, insert brick or wooden wedges to hold the brick in place until it sets up; remove wedges and point gaps.

Jim
Reply With Quote
  #15  
Old 05-24-2006, 07:19 PM
Marcel's Avatar
Journeyman
 
Join Date: Aug 2005
Location: Oregon
Posts: 426
Default I didn't mortar the 1st ring

Quote:
Originally Posted by DrakeRemoray
Thanks for the help Luis, Both Fio and I are using the "new" design which calls for resting the hearth bricks directly on the insulating layer.

My question (and Fio's) about the first few rings of dome brick still stands.

Luis mortared his first dome ring on the outside only.
Mike mortared his first dome ring to the floor.

Do most people mortar the first ring to the floor or just put mortar on the outside of the dome?
Drake
(M) Looks like you're having trouble getting concensus here. The reason I did *not* mortar the first ring is to allow the brick floor to expand with the heat and not threaten the structural integrity of the dome. This is a debatable theory however since the argument could be made that since the dome and the floor are of the same material (not counting the refractory cladding on the dome's outside) that the dome should expand at the same rate as the floor. I said debateable because temperature differences have been noted between the floor and the dome. That is likely caused by the fact that though the dome and the floor are of the same material, the floor uses the narrow side to set pizza on, whereas the dome is almost twice as thick as the floor because of how it's bricks are cut.

(M) As I see it, a teacup turned over so it is sitting on it's rim has the same compressive strength as it would have if it were glued to the supporting table. That, and the possibility of unequal coefficients of expansion constitutes my specious argument for leaving the first ring unmortared.

(M) The most frequently voiced concern I've read on this forum is that the dome would collapse once completed, not that the entire dome would shift. Quien Sabe?

(M) Ultimately, we may be worrying this to death and either way would be OK.

Ciao,

Marcel
__________________
"Everything should be made as simple as possible, ...
but no simpler!" (Albert Einstein)

Last edited by Marcel; 05-25-2006 at 07:49 AM. Reason: Error: Dome is 4.5 inches. floor only 2.5 inches & spelling
Reply With Quote
  #16  
Old 05-25-2006, 04:48 AM
Fio Fio is offline
Apprentice
 
Join Date: Apr 2006
Location: Virginia
Posts: 166
Default These pictures illustrate my hearth construction

These pictures show how my hearth is constructed. The firebricks rest on 2" of fiberfrax board, "bonded" with fireclay. The concrete slab underneath performs no thermal function. All the heat will stay in the bricks.
Attached Thumbnails
I've laid the oven floor bricks: 4 questions-completed-floor.jpg   I've laid the oven floor bricks: 4 questions-hearth-insulation.jpg  
__________________
There is nothing quite so satisfying as drinking a cold beer, while tending a hot fire, in an oven that you built yourself, and making the best pizza that your friends have ever had.
Reply With Quote
  #17  
Old 05-25-2006, 05:28 AM
Journeyman
 
Join Date: Apr 2005
Location: Brazil
Posts: 306
Default

James:

Thanks.
Yes, there is a fireplace in the corner, used for barbecue/grilling. It has been there several years ago, and the oven was finished trying to ‘mimic’ the external fireplace and table layout.
Normally, the oven is used at dinner time and the fireplace for lunch. Pizza Saturday night and barbecue on Sunday.
More pics next.

Drake

I agree with Marcel and I am convinced that it is better do not mortar down the first course of bricks.
Do not forget that the complete oven dome will be structurally strong and will weight several hundred pounds, being distributed all on your hearth.
I did use a rounded plastic garden table to maintain the first brick course in place!
LOL, and your dome is not going to collapse!. However, your belly do will have a lot of work the working on pizzas mass …

Les

Yes, the external red bricks are curved. Pics following. Not just the top, I will take a picture asap and will post it here.

Luis
Attached Thumbnails
I've laid the oven floor bricks: 4 questions-ovenended-001.jpg   I've laid the oven floor bricks: 4 questions-ovenended-004.jpg   I've laid the oven floor bricks: 4 questions-ovenended-005.jpg   I've laid the oven floor bricks: 4 questions-ovenended-008.jpg   I've laid the oven floor bricks: 4 questions-firstpizzaparty080406-005.jpg  

Reply With Quote
  #18  
Old 05-25-2006, 08:13 AM
Marcel's Avatar
Journeyman
 
Join Date: Aug 2005
Location: Oregon
Posts: 426
Question Luis' damper, and dome facade questions

(M) Hi, Luis,

(M) Your UNclad dome is still one of the most beautiful I've seen!

(M) I have saved older images of your dome under construction. The exposed red brick covering seems to be a new addition. Am I correct? ___

(M) Are those facade bricks thinner than your dome bricks underneath? __

(M) When I look at the older images I see not only Perlcrete insulation, but a blanket insulation as well. That suggests to me that your oven is probably smaller than the 42", and maybe even smaller than the 39". How large is your oven? ___

(M) I also included a damper in my chimney flue. But as I wrote in an earlier posting, because the chimney is outside the dome, I found no reason to use my damper. How and when do you use yours? ___

(M) If it is closed doesn't the smoke simply exit the throat onto your face? ___

Obrigado,

Marcel
__________________
"Everything should be made as simple as possible, ...
but no simpler!" (Albert Einstein)
Reply With Quote
  #19  
Old 05-25-2006, 08:55 AM
Journeyman
 
Join Date: Apr 2005
Location: Brazil
Posts: 306
Default

Hi, Marcel

Nice to talk with you again.
Thanks Gosh, even if my English is not better, my oven do really is. And the pizzas, uauh!!! LOL
Thanks for your words. As an engineer I could see a lot of things to change and, of course, the oven needs an acid cleaning too. But I am happy with the results.
There is an old citation: ‘Built your first home to your enemy, your second one to your friend and remain with your third’ …well, it is my first oven and I am thinking that I could remain with it 
Answering your questions
Yes, if you could cut the dome of the oven vertically by middle, you could see, internally to externally view, 4 inches of half refractory bricks, may be between ½ to one inches of cladding, a glass fiber blanket insulation, chicken wire, nearly 3, 31/2 inches of 8:1 ratio of vermiculite/concrete insulation and the necessary cladding to maintain the half inches, external curved red bricks.
Yes, has I had wrote above, the external bricks are four times thinner than the dome bricks, half to two inches ratio.
The internal dome size (baking zone) is 41 inches (exactly the size of the plastic blue table top that you could see in the pictures). Do figure that?
The damper is used when the fire is in the ‘baking pizzas’ regime, meaning: hottest the chimney, better and greater the flux of gases by it, then more hot air extracted/suctioned from the oven. The damper let you equilibrate this equation to optimize the use of wood.
May be you lost some eyebrows until reach the equilibrium LOL

Luis
Attached Thumbnails
I've laid the oven floor bricks: 4 questions-isolation11.jpg   I've laid the oven floor bricks: 4 questions-domedoordetail.jpg   I've laid the oven floor bricks: 4 questions-domefinishing-005.jpg   I've laid the oven floor bricks: 4 questions-chimeneadumper1-r-.jpg   I've laid the oven floor bricks: 4 questions-firstpizzaparty080406-003-retrab.jpg  

Reply With Quote
  #20  
Old 05-29-2006, 05:31 AM
Journeyman
 
Join Date: Apr 2005
Location: Brazil
Posts: 306
Default Some pics answering questions

Fio, James and Marcel:

All of you request some pics (or I am thinking that some pics could be a better answer to posted questions).
Then there are.
Post 1 from 2.

Luis
Attached Thumbnails
I've laid the oven floor bricks: 4 questions-ovenended2-003.jpg   I've laid the oven floor bricks: 4 questions-ovenended2-004.jpg   I've laid the oven floor bricks: 4 questions-ovenended2-006.jpg   I've laid the oven floor bricks: 4 questions-ovenended2-008.jpg   I've laid the oven floor bricks: 4 questions-ovenended2-009.jpg  

Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 05:17 AM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
© 2006/10 Forno Bravo, LLC