Rebuilding and remodeling the Shop Dragon

The 7" Batchbox in my shop has been through many changes.
Years ago, it started as an 8" J-Tube with a barrel and a brick bell.
I was informed by the armchair experts of the time that I could not do such a thing!
I did not listen, built it my way, and proved the "experts" mistaken... (WRONG)  With superwool and cob mortar, you can do almost anything!
A few years later, I converted it to my first Batchbox. This was when I learned about batchbox doors...
Initially, I  followed Matt Walker's thoughts on using aluminum and Ceramic fireboard (CFB).
After a few weeks, it was a stunning failure, during which time I watched aluminum melt and learned just how powerful and hot-burning Peter's Batchboxes really were!

This was the moment when the first Dragon Technology Batchbox door was envisioned and built.
I wanted a spark-proof door with a window, but nobody made one, so I  designed and built the first one.
My second door is proudly installed on Matt Walker's tiny cook stove in his home.
Now, years later, they are installed all over North America!

This stove had an experimental cast-iron roof. I wanted to know if cast-iron could withstand extreme burning.
The answer is... No, it can not stand up to back-to-back fires all day.
It is a viable roof option for a casual-use batchbox. I know of one installed on an 8" for many years with no issues.
This roof needed to go away. I was pleased it lasted through most of the past season.

The other change I made was to turn the entire core 90 degrees, to make loading more convenient.
This required building a new plinth to support the core's new configuration.

Here are the before and after pictures.
Teardown and build posts to follow.

Amazing how fast and easy (although very messy) it is to tear down a clay mortar-built stove!
In 2 hours, I had the whole core disassembled and on the floor.
Rebuilding takes a wee bit more time...
When using a clay mortar, you must carefully go up a few layers before stopping and letting the mortar dry.
Unlike concrete, which dries by chemical reaction, a clay/sand mortar should air dry overnight before adding more weight.

First, I filled in the west-facing plinth, and then constructed the new south-facing plinth for the core to sit on.
Unfortunately, I should have built the new plinth one brick wider, as I needed to fabricate a metal support piece to hold the front surround bricks safely.
Broken brick, cement-covered old bricks, and sand were all used as fill inside the plinth.

The base of the core must be firm and level.  Constant checking to keep everything square and level.
I needed to fabricate the metal piece to support the front two surround bricks, if only I had made that plinth one brick wider,,,
The firebricks are 2.5" thick, and the secondary tube for a 7" is 2" thick. I used fine sand to bring it up to level with the floor.
Ash will cover and insulate the secondary tube from the high heat.
Once your base is level and your secondary tube is set, you can start stacking walls.

Thomas, how many RMH do you have?
This was a dragon rebuild you did 2 yeras ago https://permies.com/t/190599/Finishing-touches-Shop-Dragon-rebuild
Nowt here is the current rebuild and then there is the Shorty Core!!

Hi John;
I currently have four.
Shorty Core
The Shop Dragon (two years ago she got the cast iron roof installed as an experiment.)
The Studio Dragon (She is getting a complete tear-down and rebuild next month)
The Walker Black & White oven

I'll have to build a bunk house for the kids, and then I'll give it a Dragon as well!

For a roof, I used a 12" x 12" slab that we had left over from the Shorty core build and four Scamal IFB bricks.
The Scamals are only rated to 1700°F. I coated them with the 5000°F IFC ceramic, and they sit on angle iron Tee-bars wrapped with Superwool.
The metal support bracket was used for the first brick on the surround. This would not have been needed if I had made the plinth one brick wider.
It works, so everything is good for me.

I slowly brought up the east retaining wall, carefully tying the two walls together.
I used a long sawsall blade held with vice grips to saw out the old clay mortar and remove bricks where needed.
Next, was lifting the lower barrel over the riser and placing it on the core.
Clay mortar was used to seal the barrel to the core.
Then I used superwool to seal the barrel to the brick wall in the back.
On the front side, I carefully cut each brick close to but not touching the barrel and sealed them with clay mortar.
The bell roof is made of cement board and sits on angle iron tee bars.
It is carefully cut around the barrel, and superwool is stuffed in the crack.

After the lower barrel was in place and the mortar set up overnight, I  was able to install the second barrel on top.
Several years ago, I installed a rope block and tackle over my barrels.
This allowed me to lift the upper barrel and leave it hanging while rebuilding.
Much easier than trying to place it by hand alone.

The first firing after her rebuild went flawlessly.
The only smoke leaks were where the two barrels joined together. They stopped as soon as the exhaust reached running temperatures.
I'll need to remove the clamp and stuff superwool inside to seal it up.
We are still getting morning temperatures in the 30s, so I am happy to have my Shop Dragon back. It makes the shop much more pleasant.

The tiles on top are temporary, I need to choose and order matching ones.
As I learned with Shorty, a careful application of cooking oil brings out the deep, rich, brick red after drying.

Thanks for the many photos to illustrate your process.  You are a master of the craft, saving energy one brick at a time