building material: clay, straw, sand, water, stones, crashed
charcoal
construction material: tiles, ceramic or metal pipe or
wood block of proper dimensions (for burning space, fig. 8), supporting
bricks, metal frame (collar, fig. 17), newspaper/cardboard
tools:
wheel borrow, plastic container, bucket, shovel, pick, spade, trowel (for
mixing), lawn mower or chopping block, ax or machete, willow shoots, rope
for final form fixing and holding, wood sticks (lintels, fig. 16), measuring
tape, level, hands for the actual building and forming and bare feet for
trampling and homogenizing of the mixture.
methods:
clay digging (fig. 1)
The basic building material is a good-quality clay; if
you have clay on your site, use it. Ideally, dig clay one day before
the building and leave soaking in water in a plastic container (the amount
of water depends on the water content in the clay itself). Clay will soften
and will allow easier processing the next day.
sand Use any available sand including river sand.
straw trimming (figs. 2-4) A lawn mower is ideal for trimming
straw to fine pieces (figs. 2, 4), straw can be also cut well by an ax or
machete on a chopping block (figs. 3, 4).
mixing the adobe building material for the actual construction (figs. 5, 6)
Combine the soaked clay with sand in a ratio 3:1-5:1 (sand: clay), add
trimmed straw (you can also use seed papus from thistle, hair etc.) and mix
well (with bare feet, figs. 5, 6) until we reach a homogenous consistency,
which passes so called worm test – roll a worm, bend it and if it does not
crack or droll, the building mixture is ready to use.
isolation material (figs. 5, 9, 10, 12, 13) A mixture of clay
and crashed charcoal is suitable for isolation of the burning compartment
and chimney (figs. 5, 9, 10, 12, 13). The mixture is made as the base clay
mixture above in a ratio 3:1 (charcoal: clay), make a clay layer of 4 cm.
plastering can be made from the same material as the base
construction mixture, without added sand (and without straw and other
additives). This mixture should be thinner for easier spreading.
II. construction:
construction design and dimensions
pot size ( l )
"h" (cm)
"d" (cm)
"k" (cm)
"a", "c" (cm)
"j" (cm)
"s" (cm)
"p" (cm)
10 - 20
38
12
25
15 x 15
13
15
15
21 - 40
41
15
26
18 x 18
15
15
16
41 - 60
44
18
28
19 x 19
16
15
17
61 - 80
47
19
29
20 x 20
18
15
19
81 - 100
50
20
30
21 x 21
20
15
20
cylinder diameter "Ø" = pot diameter
+ 4 cm
construction and supportive structures (figs.
8,9,10,11,14,15, 17, 18,22)
Draw the outline of the stove openings and place a form for burning space,
form for loading opening an form for the ventilation (fig. 8). The loading
opening will be heavily used and often scratched; therefore we used tiles
for support. All forms that will be removed cover in newspaper and wet with
water to allow easy removal after building is finished.
isolation layer (figs. 9, 10), 4 cm thick, place on the cover of
the burning space and the chimney (figs. 12, 13).
building the stove body Stones or dried mud bricks are suitable
for the main construction as they help eliminate major cracks.
supports Especially the ‘ceiling’ of the chimney needs support,
this can be ceramic plates or wood sticks (fig. 16), which will burn out
during the stove use. The edges can be supported by a willow wreath (fig.
18) or tied with a rope. A metal collar of the stove can be only a support,
which we later remove (fig. 23), or we can also firmly build it in clay and
in that case it is necessary to make dilatation joints. The collar will be
expanding with heat more than the clay coat and without the dilatation
joints, cracks would form. We further used burn proof plates for the stove
body, figs. 15, 17, 22), and balanced their position with a level (fig. 14)
or pot with water.
III. final phase:
When the basic stove shape is finished (figs. 19, 20), we can employ our
creativity and give the stove artistic view. For thicker layers we use the
mixture for the main construction, for details we use mixture without the
added straw. Smooth the surface by wet hands or use sponge soaked in water.
IV. drying and stove use:
Finished stove (figs. 26-32) needs to dry for several weeks before first
use. With the first use we need to be careful, keeping medium fire, so the
stove dries slowly.
Rocket stove can be build within 1 day. Preparation takes the longest time
(up to 3 hours), we recommend to soak the clay one day ahead, prepare the
straw and organize enough bare feet enthusiastic to work (trample) the
building mixture. The main construction took us ca 3 hours, finishing and
artistic design ca 2 hours.
