Rubber Ball for Last Courses of Dome

[Jim from Akron]

I've seen a lot of pics and vids of people using a rubber ball in their dome as a form for the last courses of firebrick. Does anyone know what size ball is best for a 36" Pompeii oven?

[UtahBeehiver]

FYI, If you go this route, you will not be able to observe or correct the mortar joints in the inside, you will either see gaps or excess from the and the mortar will have set up by time you can do a visual. IMHO, it would be better to take time, use notched sticks to hold bricks in place. I originally tried a platform to close the dome but found I could not clean up or inspect the inner dome joints.

[NewEnglandNewb]

I’ll second Russell’s recommendation. For the last two full courses, I ended up cutting each brick to fit tightly into the locations was going to be placed using a combination of my wet saw and an angle grinder. For those two courses I couldn’t fit my IT in there to help place them but found I didn’t need it. The fit of each brick was good enough that the mortar held it in place with any support. That also allowed me to immediately fill gaps and clean up excess mortar from the inside. Mine isn’t perfect but I’m happy with the results.