The other day I had the opportunity to get 2 more finishing touches on my rocket.
The first was to install a small metal door to control primary and secondary air flow.
EDIT: Peter van den Berg has suggested to me earlier here
that air flow should be either open or closed and not inbetween. So when I say controlling air flow, I mean a way to open the air port fully so that the burn has plenty of Oxygen to burn clean and hot and closed when the fire is down to coals only and don't want to push any further heat up the chimney, but rather keep as much of it in the mass for it to absorb.
The metal was from a skin off a hot water tank and the wire from a coat hanger - Remember a time when they were metal and not all plastic?
Carved a slot in the cob on either side of the air opening, then bent the coat hanger to get lots of surface area for the cob to grab and hold the door in place.
Cobbed in and shaped so it opens and closes properly and ready for the final plaster layer to make it look pretty
The second finishing touch was the final plaster layer to finish up the firebox. I used about a 3 sand to 1 clay ratio with cattail fluff and a little bit of wheat paste as my recipe. After drying, it turned out quite hard and not chalky. I went with a more rough look using my hands to smooth the surface which tends to lift the sand up a bit like a wooden trowel does rather than a smooth finish like a steel trowel does.
Feels more rustic and homemade to me for this particular project. Was thinking about putting designs and stuff on it (possible future inspiration), but for now, plain-jane she is.