Oven Build in Spring

[LeeBird]

Cory, I might be confused at the term “tapered”. I believe I built a tapered arch, However I did not taper each individual arch brick to limit my use of mortar.I am referring to your previous post #24 where you said you have cut the first arch bricks and hoping to work out the angles so you can cut a few in anticipation. In my mind and on my build I cut 14 identical arch bricks, that look exactly like the two arch bricks you have pictured in post #24. I dry stacked them on the arch form and adjusted my wood arch form up or down so the joints are tight on the underside. I wanted little or no mortar on the inside where the heat is, but didn’t care how fat the Mortar joint is on the outside.
I live in Huntsville, Ut

[cbailey]

I've been wondering how the raised pivot point is going to work out. The caster I am using results in a pivot point 1 1/8 inches from the floor. The 1/4 inch plywood I'm using is actually 3/16ths. My resulting pivot point is 1 5/16ths inches above the floor. It looks like I have 2 options. 1. I can rework my IT, before I start on the second course, or 2. make the adjustments around the tapered arch you mention above. In your experience, which option do you suggest?

I'm familiar with Morgan and Hwy 84. Beautiful area.

[SableSprings]

As Russell pointed out, not having the the pivot point of your IT at floor level will make for a bit of readjustments as you go up the dome. I noticed that you are pretty much at the end of your threaded stock adjustment in the turnbuckle. Here's a link to Gulf's solution (I think it's about post three on the thread).

https://community.fornobravo.com/for...ppi-44?t=17062

So, popping out the center floor brick to lower your IT's pivot point like Gulf did is a pretty simple solution to the problem (and the best IMHO ). Next best option would be to cut down your thread stock to allow more adjustment at the turnbuckle. Looking good so far!

Also, here's another great spreadsheet for angles and brick counts created by DeeJayOh

https://community.fornobravo.com/for...=1545242023988

p.s. I do not have the Angle Izer software in my archived files. Actually, I think you can get pretty good results setting the angle on the tool from your base brick to "angle transfer" to the brick that needs the cut. Also, I found that the pencil line on a brick being cut with a wet saw gets washed away pretty easily...magic marker works better if you want to see the line throughout the cutting process.

[cbailey]

Thanks Mike! Great suggestions and direction. Not much I can do until the weekend. I have family in town for the Holidays. I must play the host. However, the weather looks good for the weekend. I hope to make some progress, post a few pics and ask more questions.

Cory

[UtahBeehiver]

The Anglelizer works really good for determining how to make the brick taper for a user defined joint width based on arch height and width and size of brick. I am not talking about the tapered "inner" portion of the inner arch only the face of the arch.


I agree with Mike that the best solution is a pivot point at floor elevation and Gulf's solution of removing a brick and placing a wood block is a good solution.

[cbailey]

LeeBird,

Thank you for you suggestions. I agree with you on looking for tight tolerances with the brick facing the oven. However, I'm not looking to build a mortar-less dome. They are beautiful, and a testament to skill and perseverance. What I've gleaned from reading dozens of builds is that a minimalist approach to mortar joints will reduce cracking, but cracking still occurs. Cracked domes will still provide years of service. For function, I'm not sure the effort is worth the time.

Just my humble opinion.

That said I would like to avoid gaps over 1/2 inch if at all possible. Also from what I've read, most mortar mixes don't recommend large gaps (greater than 1/2 inch, for example). More so for refractory mortar joints. I don't know how Homebrew performs in filling large gaps. But I think it is reasonable to assume larger gaps are less than ideal. So I plan to trim bricks as needed to meet that goal.

At this point I may trim the arch bricks. I've worked out the angles, but was interested in the AngleIzer to verify my calculations.

I know Huntsville. Beautiful valley. Used to ski Snow Basin, water ski on Pineview, and frequent the Shooting Star.

[cbailey]

Completed course 2 over the weekend, except for the arch tie in. Apologies for the shadows. In using the IT to determine the cuts for the inner arch blocks, it looks like the top dead center brick/keystone will extend approximately 1/2 inch further into the dome than the base arch bricks. Makes sense. The dome is curving away from vertically built arch.

I'm mildly concerned about the quality of the firebrick I'm using. It is made by Butler. I've read a few comments about it being too porous. It leaves a nice smooth cut using the brick saw. However, if leaves a very porous surface when I use a grinder to shape a brick. Is their any experience with this brick long term? Does it degrade faster than other bricks?

[UtahBeehiver]

You can do one of three things to correct the 1/2" over hang at top dead center, adjust you IT all thread outwards so the bottom of the IT bracket hits the top of the arch for, or draw a line from the arch form to the 90 degree angle point or lastly, leave it as is. Remember, that each brick either side of TDC is slightly different and you really cannot but them all the same. The most critical angle is the top angle of the tapered arch brick since this the mating point between the dome and the tapered arch.

[cbailey]

I am unhappy with the Butler firebrick I am using. The factory edges are generally badly chipped, making them less that desirable any points that will be visible. I'm currently on the 4th course. It will not be long before I'll need to start cutting 1/3 brick. I won't be able to use the Butler brick. I have access to Whitaker-Greer brick. I cannot find anyone in the Houston area that carries Alsey firebrick. What other firebrick manufacturers are available?

cory

[cbailey]

I picked up Whitaker -Greer firebrick today. WHAT A DIFFERENCE! the WG brick is uniform on all sides, free from chips, and overall superior in every respect to the Butler brick that is commonly available in Texas. I've attached several side by side photos.

I wish I had this brick from the beginning. I would have not had any issues with leveling the floor.

I'm looking forward to at least a day and a half of clear building weather here in Houston. I would have stated 2 days, but I have to fit in some golf.

[cbailey]

Started course 5. Hoping to transition the arch this weekend.

[UtahBeehiver]

FYI,

Keep the tapered arch bricks ahead of the dome bricks, much easier to mate into the arch.

[cbailey]

I made some progress over the weekend. Did not transition the arch, as was my original goal. But did install the keystone in the arch, completed the fifth course and started the 6 course.

I made a right and left jig to help with the brick cuts. Originally, I wasn't going to get too concerned with inverted V's, etc. However, The big gaps just did not look right. I wanted a jig that would be waterproof. I picked up a couple of cheap cutting board at Walmart ($0.99 each), and some 3/4 inch aluminum angle to use as a brick stop. The black line through the middle indicates the width of the brick, 4.5 inches. By dry fitting 1/2 bricks you can measure the width of the V at the widest point. Divide that number by 2 and you get the shim that must be placed beneath the black line. I've been using 3/16th inch plywood, popsicle type mixing sticks, etc. to achieve the required space or lift. It works quite well, and cleans up easily.

As we all have found, the saw gets quite dirty, particularly when trimming brick. I've been using a typical gardening pump sprayer to rinse off the tray when ever needed. It uses far less water than a garden hose, so it doesn't fill up the water catch tray, and it keeps the work area dry.

[cbailey]

I made some progress this weekend. Transitioned the arch with course 6 and completed course 7, however it was too dark when I finished to get a good photo.

The sixth course transition the arch. I have to thank the forum for warning about the arch droop. I was able to transition with only about 1/16th inch droop.

I used Sten's Dome Claw idea to help hold course 7 bricks in place. I had more success with using steel from Simpson Strong Ties than with bar aluminum. The steel is more forgiving and acts as a spring.

It looks like it may freeze a few time over the next week. The temperatures have been low here, 40s to 50s, and has really slowed the initial grab with the mortar on brick. The Claw's have helped a lot. I've place a work light in the dome to add some heat and a blanket over it to maintain it. Hopefully I'll get a strong cure.

More work on it this weekend.

[cbailey]

I’ve made pretty good progress in the last few weeks. The progress is always about half of what I want to accomplish, but such is life. I’m going to divide things up in 3 different posts. This being the first

I made an update to my saw jig. I’ve replaced using shims with two 5/16^th by 20 bolts. The nut on the underside sets the height (or depth) of the angle while the wing nut on the top side locks it into place. I can better control the angle of the cut with a greater accuracy and repeatability. Its easy to make adjustments. With 20 threads per inch 1/16” is 1.25 turns of the nut.