Need Help Connecting Dome Courses to Landing Arch

[artistadimattoni]

I am not sure how to connect the series of landing arches (I will have 3) to the dome. Should I have the arch that connects back on the outside perimeter of the base 36" circle? Does anyone have a plan layout or good pictures of this kind of connection? Please help!

[Mongo]

I recommend doing what's referred to as the tapered arch. Attached is a photo courtesy of UtahBeehiver
I'd study his build, don't get too intimidated.
It's a difficult concept to visualize. It's a plane intersecting a dome.
My build thread has a few good photos of the tapered arch as do many others.


Scour the forum and good luck.

You are not going to find a set of plans anywhere in the sense of "fit piece A into Slot B".

BTW, your photos are very small and hard to see exactly what's going on.

-George

[JRPizza]

Your pics are kind of small, but it looks like you pre-built your arch - is that correct? If you did it looks like you used a constant thickness fore-aft which may make tying into your dome problematic. Most builders put the inner dome circumference on the bottom of their arch bricks and the taper for the adjacent dome bricks on the upper surface (what Mongo was showing above). In the first pic below you can see where I marked the TDC arch brick with the inner surface curve (mark on lower left) and where I was going to cut for the dome brick that was going to top the arch (line on upper left). Ignore the marks on the right of the brick they were a mistake The second picture just shows part of tying the dome into the arch. Lastly I attached an ISO sketch showing the shape of the bricks at the bottom of the arch and at the top. The corners of the brick that are sticking out into the oven were cut off.

[artistadimattoni]

Thanks for the help! I have been looking again at all of the relevant forums, and it is clear that I need to re-cut the bricks of the landing arch that intersects the dome. I'm using some very dense firebrick that I found which were likely intended to be used in a glass making furnace. They are like granite. I should have enough to recut. I will need to re-do my IT so I can use it as a marker as well.

Can anyone steer me to the best posts for IT tools and how to upload photos easily? I haven't had this much trouble before. I appreciate the help!

[artistadimattoni]

Thank you for the help with the connection of the dome to the arch. I think I have the plan figured out, but I think my IT is causing some of the confusion. I don't know if my pivot arm is causing the problem or the placement of the castor assembly isn't the best system to use. I have tried attaching it to a wood base recessed when removing the floor brick as well as on top of a 3/4" plywood base installed on top of the floor bricks.

Here's the problem: I am getting about 1/8" set back for each chain/course of brick as I go up. I am really stuck here before I can proceed to cut the arch bricks that connect to the dome as well as getting the bricks ready to mortar! Is the problem the IT, the swivel castor assembly, my calculations for the brick taper?

[UtahBeehiver]

The IT has an horizontal offset from the center point of the floor. The pivot point and the center of the floor need to be the same and the pivot point and the floor elevation should be the same as well which by recessing the ply it looks like that end is close to floor elevation. So in order to make the dome and arch work you will either have to correct the center point/pivot point or adjust the IT length to correct the error induced by the offset for each course.

[artistadimattoni]

Thanks for the help! I corrected my central pivot, but without any welding abilities, I found a rotating magnet that I was able to retrofit for the arm. I am getting the arch bricks cut slowly, but I have put some time into the pizza oven stand/hearth. Over the winter, a couple of cracks appeared on the top and sides near the front 12" of the insulating layer. I could hear hollow-sounding areas along the crack near the front 12". I used the formula for perlite/concrete from the FB plans, and had two layers with several batches mixed in each layer. The front 12" of the topmost layer was mostly concrete as I ran out of perlite. Now I have widened the cracks with my angle grinder to get to solid concrete, and I am finding wet/crumbly areas. I stopped grinding and chiseling, as I am wondering if I need to remove the entire insulating concrete layer and re-pour?