riser is about 4', welded together at 90 degrees. i trimmed a 6" damper
plate used for woodstoves and bolted it together in the top of the
riser. it worked well with only one 5' section of stove pipe, but heated
much faster when i added another 5' section. at over 10' i had to add
some guy wires and also couldn't leave it assembled since a good wind
gust would blow it over. the chimney cap is an aluminum hot water heater
vent cap. i welded two 1/2" bolts to the bottom and used them to attach
the heat bent leaf springs leftover from a suspension upgrade on my
chevy astro camper conversion.
if i were to do it over i would
use a 6"-8" pipe, add a clean out at the rear and a fire grate. i'd
leave the chimney at 4.5"-6". a 6" riser would eliminate the need to
refabricate the damper and allow more room for larger pieces. the upper
heavy steel riser should also be completely replaced with stove pipe.
the thinner the chimney metal the faster and hotter it will get. the
heavier steel chimney takes longer to heat up making it harder to light.
i no longer own this one and have another rocket stove i'm
tinkering with that would work better for forging. the 4.5" diameter
pipe is too small to heat and bend a stirrup, unless you could manage to
make all your bends before it cools. i'll try to take a few pictures of
it, because it's easier to build and more functional. it is basically a stack of bricks
with a 5' section of 8" double wall chimney sitting on top. eventually it will become the business end of a thermal mass rocket heater.