Simmental Farm 36" Pompeii and 48" Rumford Style Fireplace

[Gulf]

My first IT had at turnbuckle mated to the all thread for adjustments. The new IT does not. My first IT was not designed to be center of the brick. That may have been the reason that I did not have adjust the IT during the build. I'm not sure? This one is designed to have the direct center of the dome inline with 1/2 the thickness of the brick. No adjustments were needed during this build either. Only a minimal adjustment point was designed into the new IT.

[Gulf]

That adjustment point (only to set the final adjustment) is an all thread connector at the base of the IT head. A nut is threaded in line against the connector to lock the IT head in place.

An addition to this post is coming. My bed is calling me now. It's been a long cold day down here in Mississippi .

[Gulf]

The IT head is made from an off the shelf corner bracket, an all thread connector, a bolt, and a nut to lock the head in place. The 6"X6" bracket was cut down to fit the dimensions of the 1/2 bricks used to build the majority of the dome. I used some slightly less than 3/4" blocks that were cut from an from old bed slats. I'm not sure of the species of wood. I cut thin plywood spacers from 1/4" and 3/16" stock to align the the all thread connection with a factory drilled hole that was in the bracket. This was to align 1/2 the thickness of the brick.

This IT was designed to be cut down later, but we decided not since it will be used for another identical build. So, Don made a second IT that was narrower for the 1/3rd and 1/4 bricks on the upper courses. The head of the bolt used was cut down to allow it to be easily countersunk in the wooden block. I used a hand drill for this on the full sized IT but, Don has a drill press that makes it a little easier for building the narrower IT.

[Gulf]

Extra holes were drilled in the bracket for wood screws to secure the bracket to the wood blocks. The IT is built heavy duty since it will be used for multiple builds and also for another reason that will be apparent later in the build.

[Gulf]

In total, there were four all thread attachments built for this oven. The two IT's and a couple of attachments used to scribe the inner arch.

The scribing attachments were also made from all thread. 5/16th in this case, because it fit one of my old coping saws without alterations. Both scribing attachments are fitted to the pivot point as was the ITs.

[Gulf]

The oven floor brick were scribed and cut to fit inside the dome walls allowing for a cardboard space as an expansion joint.. We taped the cardboard spacer around the perimeter and laid the first course of dome brick. Next up was setting the arch form. The face of the form was set 21 3/4" from the center of the dome. That placement was soon to be changed.

[Gulf]

With the arch brick dry stacked we started scribing the arch with the ID and OD tools. We discovered that the arch was placed too far forward.

On the drawing, I had plotted the first riser and the top dead center arch bricks. That works well for a hemispherical arch, but this is a segmental arch. On a segmental arch the top risers and springers (skew back) protrude furthest into the dome away from the face of the arch. I went back to the template later to see how that could have been predicted. The third pic shows that adding the height of the risers to the inside face of the first riser places it outside of the ID of the dome.

We moved the face of the arch in to 19" from the center of the dome. That move gives Don a slightly deep entry. He's okay with that since he wants to use that area for grilling steaks.

[Gulf]

The arch was scribed ID and OD completely while dry stacked with the scribing tools. We didn't get pics during that process, but this pic was staged to show how the OD tool reaches around the uncut brick to get a 22" OD mark for a 36" dome. The OD is fairly easy as it is just one mark on the outside of the arch.

[Gulf]

However, the ID scribe takes a couple more steps to complete. The ID attachment is first used to scribe the inside of the arch. At some point down the risers it will run out of brick to mark and will then be used to mark the inside face of the inner arch brick. Again, at some point the ID tool will run out of the inside face to mark. From there that point is scribed down to the intersection of the floor brick using a radius tool. In this case we made a quick ID radius on a piece of card board to transfer that mark. I know that last step is clear as mud, but I will try to stage another pic later and add it to this post.

[Gulf]

As each brick is removed from the dry stack, we connected both ID marks using the ID radius tool. Measuring up 1 1/2" ( for a reveal) from the underside mark we connected a line out to the OD mark. We used color coded permanent markers for this step to eliminate confusion at the wet saw. The markers also hold up to the water spray and don't disappear while cutting.

That slope is not very much different than using the string method, but it makes a clean intersection both inside and outside the inner arch.

[Gulf]

Another dry stack after cutting. We placed the ID and OD tools in this pic for clarity. I hope this gives a little more perspective on a brick segmental arch.

EDIT: Unable to restore original post with all the pics. See post # 29

[UtahBeehiver]

Great tapered inner arch on a "axe" arch.

[Gulf]

Great tapered inner arch on a "axe" arch.

Thanks Russell,

There can be some confusion on arch terms. Since I did not taper the vouissoirs, I'm not sure that it can be called an "axe" or "axed" arch?

[Gulf]

Edit: to replace post 26

Another dry stack after cutting. We placed the ID and OD tools in this pic for clarity. I hope this gives a little more perspective on a brick segmental arch.

[Gulf]

Don kept the build organized. Each arch brick was marked and set aside until needed.