Gus : Expect a P.M. From Me ! Yes it definitely was Simon Leach, I am sure that none or very few of us think in terms of glass furnaces,
just about a year ago Ernie and Erica Wisner were doing a workshop in Montana, and Erica had built a industrial soup kitchen model that
a little
ego and a little egging on lead to a head to head cooking time contest with one of those whole-turkey-frying-oil-bath, too-loud-
to-carry-on-a conversation monsters! Time, and a few modifications later (running only on very dry hard wood ) They had internal parts
running at metal forging temps -so of course a few twisted shaft fire place pokers were run up on the spot ! So yes, we can talk about
forging as a comparison ! Also the warping and carbonization and failure of even stainless steel, bricks rule, steel drools (and puddles )
Sustained wood fires kinda, with soft fire brick and super high temp refractory /ceramic blankets wrapped around the soft brick we can
easily maintain high enough temps using very little wood, (the inside dimensions of a Rockets combustion chamber on an 8'' system is
only 7'' by 7+'') with the previous wood nearly consumed in say an hour, and the sound of our rocket losing volume, we can expect to
look in the
feed tube, and bathing the remaining embers find a (visible in daylight ) red glow from our bricks, at this point new chunks
of wood 'fed in' seem to miraculously burst into flame! I thought anagama was the name of a Bread made with more than one type of
whole grain floor
Southern groundhog kilns have much in common with fox fires, or foxhole fires, and date back at least to the early
kilns designed to burn pine and collect ships tar (creosote ) and turpentine, local descendants are still called tar heels !
With cement, I was pretty sure that your answer was going to be, but as always we are leaving a trail for others to follow so I asked for
clarification, certainly in the reduced oxygen concentrations found in the RMHs Heat Riser we would see a flux forming if someone tried
to use it there, generally we say that 'The Lime starts to fail!'
Bricks, the Sheffield prices on the chart you sent me seem pricey, friends out west are quoting me $1.50 each, with no mention of
shipping charges, is there that much of a break for lots/pallets of bricks of 500 ?
About 3 weeks ago I tracked down retired SUNY Potsdam Prof.
Art Sennett and picked his brain for local clay deposits, -what I thought
for years was dense hard clay was some kind of silt masquerading as clay, and everything else I can find is Blue, or blue grey, which
apparently gets disregarded on sight (for lack of alumina?) Though he could not help me pinpoint any good clay close to home, he was
a very interesting man to talk to, our Discussion about Albany Slip was that when electrical and telephone lines went from pole to pole,
the insulators they met were coated in Albany Slip Glaze !
We covered the fact that steel does not hold up the high temps as well as brick, there is an old saying that to a man with a hammer,all
problems are nails ! If you have welding experience, building a
wood stove out of steel Can make sense, but we are not just building
wood stoves, usually the first thing I tell want-to-be rocket builders is stop watching You-Tube!!! (unless I send you there !)
One guy
builds a Frankinclone RMH-like device, and puts a video of the build on You-Tube, and says 'look what I am doing ', six months later the
video is still up there, but all comments are blocked or are 4 months old but Now there are one hundred more 'Look what I am doings',
and the original builder has lost interest, and is off chasing the next shiny bauble. Ask all of them in two years about that
Rocket stove
thing without mentioning the video and the answer is ''I tried that, they don't work " ,'' Those crooked brick markers are getting rich''
Most of the wear is due to people dropping wood in or trying to twist and press in one more chunk, but in this location emissivity, or
the material that makes up the walls of the burn tunnel's ability to re-radiate that heat back into the combustion zone is damn near all
important !
Wear is caused by general ham handedness. There are two other opposing forces here, the boundary layer of still air that can exist at
the surface area of an object, Usually called Laminar Flow, for us it should be called Laminar No-flow, And also the scrubbing effect of
high speed air and turbulence!
We insulate the combustion chamber and the heat riser ascending to the top of the Barrels interior to promote draft,and then a Miracle
occurs, actually as you know energy has to be used for work to be done, the shedding off heat off of the totally uninsulated barrel is the
work energy or 'Delta T' to an engineer, put more basically the hot rising air pushes and the rapidly cooling air rapidly sinks, push me-
pull you! This allows us to flow the still hot exhaust gases, 40 ft horizontally through our
cob thermal mass bench ! Temperatures for the
exhaust of a well built RMH at the base of its terminal vertical chimney are in the 150*F range ! I totally understand that you are used to
loading heat into hard fire brick to insure that Your kilns firing temperatures remain constant, and it is easy for the eye to see what the
mind wants it to see !
Initially I had thought that the ratio was as low as 30 % of the heat radiated into the room, but I am adjusting my thinking upwards to
40%, possibly higher!
Sand, we say that while sand is the glue the sand locks up the clay and reduces the amount/percentage of expansion and contraction,
like grog, and you don't use round spheres for that ! And masonry sand gets its name from the practice of using just sharp sand and
something close to fireclay 60 ! For the good of the Craft ! Big AL !