Forno Bravo Forum: The Wood-Fired Oven Community

Forno Bravo Forum: The Wood-Fired Oven Community (http://www.fornobravo.com/forum/)
-   Getting Started (http://www.fornobravo.com/forum/f6/)
-   -   Second course angle (http://www.fornobravo.com/forum/f6/second-course-angle-19819.html)

dmyeli 08-21-2013 04:35 AM

Second course angle
 
3 Attachment(s)
Hello everyone,

I am ready to lay down the second course of bricks and need some advice. My oven will be a low dome style oven, and I have already put down the 1st course ( I believe these are referred to as soldiers ) . The soldiers are full brick standing 9 inches high and the internal diameter is 36 inches.

My question : Do I need to be very fussy with the angle of my first course on top of the soldiers? This will be a low dome, remember, so according to the diagram on page 9 of the Forno Bravo 2.0 version, I am to use bricks cut at bout 70 degrees. However, this diagram on page 9 is the only info I've come across regarding the angle of this course for this type of style. Does this sound about right?

Other info : The oven entrance is 10 inches high, plus the additional area of the arch on top of which peaks at an additional 2 inches.

mrchipster 08-21-2013 05:12 AM

Re: Second course angle
 
Before you start the dome you will need to butress the soldiers what will be holding them up?

In most of the soldier applications I have seen the soldiers have an angle cut into the top to receive the dome.

Your inner arch will also need buttressing.

texman 08-21-2013 06:18 AM

Re: Second course angle
 
1 Attachment(s)
DM

You definitely want to start the dome curve in this next course. Like Chip says, most builders cut the top of those soldiers, but not required.

Are you planning to use an IT or a template to keep the dome curve true? Since you are building a low dome, i would suggest a template. A piece of plywood (or other rigid material) with the outside edge cut the height of the soldier and the inside edge cut to the height of the center of the dome. The will guide you on the angle required for each course of brick. Look at Octoforno template in the pic.

Si
Texman

deejayoh 08-21-2013 09:16 AM

Re: Second course angle
 
With a 10" door - I am assuming you want your dome height to be about 16" to make the ratio right at 63%. Given that you already have your 9" soldiers in place, you are going to need to angle the first course at about 50 degrees in order to hit that height.

You can use my spreadsheet to calculate the angles (see link in my sig). Set the diameter at 36", first course at 9", and IT height at minus 10.5 inches in order to account for how flat your dome is going to be. The angle for each course is shown in column N.

FWIW, you will not be able to use an IT to build this dome. And as Chip points out, you are going to need a whole lot of buttressing. Too much outward pressure for this to stay up on it's own.

Personally, I would cut those soldiers down to 4.5", angle the tops as Chip suggests, and build a more typical dome. You won't need that much height at the edges of the dome.

shuboyje 08-21-2013 09:21 AM

Re: Second course angle
 
First you need to find the radius of your dome. Once you have that use it to find the center point which will be way bellow the oven floor. Then simply extend a line from the center point to the inside top edge of the soldier course. That line will run at the angle you are after. Cad you be easier, but you could lay this out on the ground the old fashion way in no time.

deejayoh 08-21-2013 09:29 AM

Re: Second course angle
 
Quote:

Originally Posted by shuboyje (Post 159995)
First you need to find the radius of your dome. Once you have that use it to find the center point which will be way bellow the oven floor. Then simply extend a line from the center point to the inside top edge of the soldier course. That line will run at the angle you are after. Cad you be easier, but you could lay this out on the ground the old fashion way in no time.

Effective radius will be 26.5", because the walls are high and the dome is so flat. He won't be able to use a string unless he can get the center point under the floor :)

Tscarborough 08-21-2013 10:40 AM

Re: Second course angle
 
The low dome makes for a nice oven, it is just a little more complicated to build.

deejayoh 08-21-2013 10:56 AM

Re: Second course angle
 
1 Attachment(s)
Here's the radius issue, in a nutshell
Attachment 38237

mrchipster 08-21-2013 11:00 AM

Re: Second course angle
 
Quote:

Originally Posted by deejayoh (Post 160004)
Here's the radius issue, in a nutshell
Attachment 38237

Nice way to boil it down to the basics.

david s 08-21-2013 12:28 PM

Re: Second course angle
 
You can make some plywood templates for support or fill with sand to required form.


All times are GMT -7. The time now is 04:02 PM.

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