Slope of brick and indispensible tool length per row

[ocafra]

I have 9x4x2 bricks.

Using the spreadsheet graciously updated to use Chipsters Jig, I was able to determine that I need 14 rows. Using Chipsters three cut jig, I was able to experiment and got four nice bricks cut at 5deg angle, and 1.5 deg wet saw bevel for the first row. So when I bring the bricks to the oven, the one unit of data I can't find is the slop of the brick. Am I missing something? I built an indispensible tool, but thought this was really just to hold the brick in place as there is no indispensible tool distance or slope given on the spreadsheet that i can locate.

I anticipate I am just completely overlooking something, but would really appreciate some guidance as to where to look for the slope of each layer, and how long the indispensible tool should be for each row.

[Tonyp]

Re: Slope of brick and indispensible tool length per row

I have 9x4x2 bricks.

Using the spreadsheet graciously updated to use Chipsters Jig, I was able to determine that I need 14 rows. Using Chipsters three cut jig, I was able to experiment and got four nice bricks cut at 5deg angle, and 1.5 deg wet saw bevel for the first row. So when I bring the bricks to the oven, the one unit of data I can't find is the slop of the brick. Am I missing something? I built an indispensible tool, but thought this was really just to hold the brick in place as there is no indispensible tool distance or slope given on the spreadsheet that i can locate.

I anticipate I am just completely overlooking something, but would really appreciate some guidance as to where to look for the slope of each layer, and how long the indispensible tool should be for each row.

The L bracket does hold the brick in place while the mortar sets up, but it also functions to set the slope of the brick as well. The L bracket on the end of the IT arm should be perpendicular to arm. The slope of the brick is then set by the top of the L bracket resting flat on the upper surface of the brick.

Length of the IT is somewhat more complicated. Most just used a fixed length IT that is half the distance of the interior width. If you keep the IT length fixed it will lead to a slightly higher dome unless you have your IT pivot point at floor level. The final oven height would then be IT length plus distance from pivot to floor when the IT is straight up. You could make the IT adjustable if you want, and shorten it slightly with each course to compensate. It's really up to you how complex you want to make matters.

Tony

[ocafra]

Re: Slope of brick and indispensible tool length per row

Thank you for the quick response. For some reason I had it in my mind the ceiling would be more elliptical. As I mentioned, I just needed somebody to turn the light on, and once I read your email and looked at a few pictures, it became obvious that most domes are circular.

Therefore, going with the circle arch, my IT tool length become fixed at 21.3 for my dome. I was then also able to calculate the angles of each brick slope pretty easy. BUT....I now see the advantage of adding the "L" bracket at the end of the IT tool, which I will promptly do. Thank you again for your quick response. Saved me a weekend of frustration. Also enjoyed reading about your oven build and reviewing your oven pictures. Great final picture of the top of of your dome from the inside. Like a cathedral!

Frank

[Tonyp]

Re: Slope of brick and indispensible tool length per row

Also enjoyed reading about your oven build and reviewing your oven pictures. Great final picture of the top of of your dome from the inside. Like a cathedral!

Frank

Thanks Frank! I am probably overly obsessive about the details. I look forward to following along with your build.

Tony

[fornax hominus]

Re: Slope of brick and indispensible tool length per row

Here is the '' L'' in action ..... good till row 6 ,, no beveling heatstop 50 refractory mortar for the inner joint , regular mortar packed in behind ..5 years on with 400+ firings..... all is well!

[ocafra]

Re: Slope of brick and indispensible tool length per row

Yes, after I got started I realized the "mathematical" answers of the slope where less relevant than simply using the IT, as Tony pointed out. Once I got started I was able to get eight rows done over the weekend. Then came time to connect to the Arch...A lot of trial and error fo me. Good thing I got the firebrick cheap!

Speaking of firebrick, Excellent picture. Are those reused firebrick? I see you did not cute the angles, and I assume you are happy with your oven. It would be nice to hear how it performs, without the extra mass of a tight cut angle. How long does it take to warm up to 900? Does it get to 900? How long does it hold the temperature?

[Tonyp]

Re: Slope of brick and indispensible tool length per row

Hi Frank,

Wow 8 rows in a weekend! Nice

The arch is often a trial and error, design in progress type thing on how to tie it to the dome

[ocafra]

Re: Slope of brick and indispensible tool length per row

My bricks are non-standard. I have 9x4x2 inch bricks, so 8 rows is not as high as you would think. Also the three cut method really sped things up. I was cutting the next row while the first one dried, waited an extra minutes, and repeated the process. I started at 8AM and went to 6PM both days. Owe my wife a day at the nail salon for selflessly watching the kids the WHOLE time. Been working an hour each night after work on connecting 8 bricks to my arch. The angles and cutting are killing me, but finally down to three. Hoping to finish up by Saturday, so I can get back to laying rows over the weekend. I suspect that from this point forward the angle will require more dry time for successive layer...six more layers to go.

Would enjoy hearing more about your oven. Seems like you really enjoy it!!

[Tonyp]

Re: Slope of brick and indispensible tool length per row

Yes as the angle increases the bricks want to slide off and fall into the oven if you rush. Many different ways to help hold the previous few bricks while you move the IT around. Some builders just use sticks between the face of the brick and the oven floor to hold them in place. I have also seen a number of clip type thingies, to using an exercise ball inside or some sort of round cut out disk the diameter of the opening to let the brick edge of the brick rest on. I ended up just going slowly and waiting for the mortar to set enough to move on. I also put little notches on the upper and lower faces which helps to hold the brick. I found as the brick in each course was progressively narrower it was also proportionally lighter which reduced the desire for the brick to slide down into the oven. Considering how slow I am at setting each brick it wasn't really an issue for me as I could just pretty much continue as I had been with just a small support stick for the previously set brick.

[ocafra]

Re: Slope of brick and indispensible tool length per row

Cutting the notches into the bottom of the brick is a great idea. I am going to use that one! I also motor each brick as I go along with Heat Stop 50, which has had great adhesion, making the brick setting quick. I will also use your idea with the sticks. I got all the Arch connecting bricks cut tonight, and will motor tomorrow. Allowing me to get started with row 9 on Saturday morning. I will let you know how your notches and sticks work out. Boylanta also had a creative idea I tried and it worked out pretty good so far. He used counter weighted 2x4's with a nail at one end that catches the bricks and holds it. Worked on Row eight pretty well. I notch the brick to catch the nail on that one, but will notch the bottom to catch the cement too now.

[seamad]

Re: Slope of brick and indispensible tool length per row

I put 2 notches on each brick (top of already laid and bottom of to be laid ) and used home brew mortar, had no slip, setup was a matter of about 5 seconds.

[fornax hominus]

Re: Slope of brick and indispensible tool length per row

Yes, after I got started I realized the "mathematical" answers of the slope where less relevant than simply using the IT, as Tony pointed out. Once I got started I was able to get eight rows done over the weekend. Then came time to connect to the Arch...A lot of trial and error fo me. Good thing I got the firebrick cheap!

Speaking of firebrick, Excellent picture. Are those reused firebrick? I see you did not cute the angles, and I assume you are happy with your oven. It would be nice to hear how it performs, without the extra mass of a tight cut angle. How long does it take to warm up to 900? Does it get to 900? How long does it hold the temperature?

Yes used fire brick . suoer duty kiln bricks ... no beveling , but interestingly row 5 is made of #1 arch bricks with the fat side to the outer dome and when the oven gets to be burning the carbon off I have a black ring of bricks for about 15 minutes till the larger back nmass takes up the heat .. all backed up with a parging of mortar , covered with 1 inch of Kaowool . @ hour heat up ..but I go very small and slow to start. I never get 900F ... 800F with the pizza fire on or for coffee roasting The following day after pizza the oven holds in the mid 300's F all day great for roasting chicken/turkey , I am way happy with my oven . A wfo changes your life !