J Tube Rocket Mass Heater Engine - metalworking.wood.rmheng PEP BB

There was a great deal of metal cutting, grinding, and welding to make this 8in rocket. I needed to split the engine into 3 sections so that it could be carried by 2 people (more like 3 people). I have a ton more photos so I picked a 'partway through build' photo that focused on the metalworking.

EDIT: Is there not a separate RMH Engine BB link for the wood-level rocket (not metalworking)? In this case, I'll also attach a partway through build with a firebrick focus.

For this BB, you will be making a J-Tube Rocket Mass Heater Engine (counts as two-fer with Rocket Badge)!

Minimum requirements:
 - Must be a heat resistant core that is wrapped with metal for durability
 - Strong enough to be moved around and handled

To document your completion of the BB, provide the photos or video (<2 min) of the following:
 - The supplies you're starting with
 - Partway through the build
 - The finished J-Tube Rocket Mass Heater Engine