Closing in...

As I started laying bricks by myself, I realized that the more difficult job of putting the bricks into increasingly vertical position was all mine...oh, joy! The options I found at the time included filling the oven with sand or a large exercise ball. I compromised and made a plywood platform just below my current brick course. On the platform I put a piece of Styrofoam that was angled slightly out (hopefully to catch wayward sand or mortar from above). On top of the Styrofoam went plastic bags full of sand and then some loose damp builder’s sand. The plastic bags would make it faster to clean up when the dome was closed and the loose sand allowed me to properly shape the dome ceiling. After I added the first chain on the sand, I started worrying about the sand sticking to the mortar and making for a difficult cleanup. Based on that thought, I laid a piece of plastic over the sand form to keep the sand and mortar separate. (Yes, that is a bag from the original SPAM museum in Austin, Minnesota.)

Now almost everyone that builds a masonry oven at home uses a variation on what’s called (at least on WFO builder sites such as Forno Bravo) the Indispensable Tool (IT) to place these "hanging bricks". Either I missed the IT (probably the case) or the idea became the defacto standard after I was past this point in my build (another one of my mental outs to avoid responsibility for doing something else the hard way...).

Anyway, I cut and laid the remaining bricks to close in the dome pretty quickly. I cut several sequential bricks, numbered them and laid them on the domed, plastic covered sand form. When I had enough cut to justify opening up the bucket of ‘Sairset high-temp mortar, I gave the bricks a quick dunk in water and mortared them into place. Because my dome had the “teardrop” shape, some of the bricks were a bit challenging to cut & fit...but I figured that was part of my penance for wanting to build my own WFO.

Being spatially challenged (and running out of bricks to cut incorrectly), I was very glad a friend came over to help cut & set in the last chain and the two part keystone. I freely admit that my adult beverage that night tasted especially good and felt quite well deserved.

No, it's not the proto-type for Stonehenge.
It's my platform for the sand dome form...to help set and
support bricks in place until the mortar grabbed. 

Sacks of sand on the Styrofoam platform were covered
with a layer of damp builders sand. The sand was then
shaped and smoothed to act as a form for the dome bricks.

The sand form worked, I just had an anxiety attack about sand
sticking to the brick mortar and added a piece of plastic to
separate them. Note that the bag is from the SPAM museum.

A fair bit of challenges here for my inability to spatially visualize
how to cut the angles for the top several brick courses...but I just thought
that with enough mortar nobody would ever see how ugly it really is.

With the help of a friend (who isn't spatially challenged), I got the
final set of bricks cut that were my keystone for the dome.
Time for an adult beverage and self-congratulations.