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Gear
SCOTT'S PEPSI-G STOVE INSTRUCTIONS
by Scott Henderson
 If you have questions or
suggestions please post to the stoves section in the Message Board on this web
site or e-mail Scott Henderson directly.
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STOVE
PARTS
Aluminum cans in mint condition (no dents), one each
of:
If you use a Murphy’s can see Notes in
STEP 5 for special instructions.
If you substitute a 12 oz can
(PepsiCo or other) for the 14.9 oz Irish beer can, see Notes in
STEPS 3, 5, and 7 for special instructions.
Note: If you can’t obtain the specific
cans listed above don’t worry. The stove may be made from just
about any two 12 oz aluminum cans. However, there are advantages
to the suggested cans. A 12 oz PepsiCo can is preferred for the
top section because the circular ridge on the bottom of a PepsiCo
can is narrower than that of other brands and forms a circular
groove on the inner surface that holds the inner wall of the stove
snugly. The 14.9 oz Irish beer cans listed above are favored for
the bottom section of the stove because the diameter of these cans
is slightly smaller than the diameter of a 12 oz can which fits
snugly over a 14.9 oz can without having to cut slits, crease, or
otherwise weaken either can. If a 12 oz can is used for the bottom
section the stove will be slightly more difficult to make and will
have a less finished look from the vertical beads of epoxy on it’s
exterior (see Fig. 17), but the stove will function
just as well.
OPTIONAL SIMMER
RING
Aluminum can, one of:
Note: The inner diameter of
the raised rim on the top of a 24 oz Miller beer can is 62 mm (2
7/16 in). Other large cans with a top rim diameter of 58 to 62 mm
(2 5/16 to 2 7/16 in) may perform as well, but all large cans do
not have the same size top.
STOVE PART DIMENSIONS: Metric or Imperial |
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Click images for larger photo.
[FIGURE 1]
[FIGURE 2]
[FIGURE 3]
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STEP 1. MAKE THE BURNER HOLES (Fig.
1)
Summary. The top section of the stove is
constructed in STEPS 1-3 from a 12 oz PepsiCo can. In STEP 1 a
sewing needle with a shaft diameter of 0.6 mm (0.024 in) is used to
make a circular ring of 32 evenly spaced holes outside and
concentric with the circular ridge on the bottom of the PepsiCo
can.
Details. Remove the pop-top tab from the top of
the can and set the can upside down on a hard, flat surface such as
a work bench or a cutting board placed on a table
top.
Tip. To achieve
evenly spaced burner holes, mark their location with a marking pen
before punching the holes (Fig. 2).
Using a hose clamp, fasten the sewing needle
to a rod with a diameter of about 13 mm (1/2 in) and a length of
about 70 mm (2 3/4 in). The needle should be parallel to the long
axis of the rod (i.e., straight, not crooked) with only 4 mm (3/16
in) of the needle extending past the end of the rod (Fig. 3). This
lessens the likelihood that the needle will bend and break off. For
the same reason, the edge of the hose clamp should be nearly flush
with the end of the rod.
Note: The rod and hose clamp are not
required, they just make the job easier. Two optional methods of
making holes with a needle are described. Option 1, pierce a cork
stopper with a needle so that the pointed end extends about 3 mm
(1/8 in) beyond the cork. Position the needle where you want a hole
and tap on the blunt end of the needle with a hammer. The cork
prevents bending of the needle. To further prevent bending, you can
trim the blunt end of the needle with wire cutters to within about 6
mm (1/4 in) of the cork. Option 2, simply grip the needle near the
point with vice grips or needle nose pliers, position the needle
where you want a hole, and pierce the aluminum can with hand
pressure..
Tip. Use one or two new needles for each
stove. New needles are sharp and pierce the aluminum better than
dull, used needles.
Cautionary Note: Protect your eyes with
safety glasses or goggles when making the burner holes.
Position the point of the needle where you
want a hole, adjust the rod so that the needle is perpendicular to
the surface at the hole, and rap gently on the end of the rod with a
hammer or simply push the needle into the can with hand pressure.
After the 32 holes are punched with the 4 mm (3/16 in) offset
needle, go back over the holes with a needle offset 9 mm (3/8 in)
past the end of the rod. Push the needle in for most, if not all, of
its exposed length. If the needle shaft feels rough at any time
during this process, smooth it with fine sandpaper (400 grit). The
goal is for each hole to have the same diameter so that the flame
will be uniform.
Tip.
The burner holes are more easily made with a push pin than a sewing
needle. For that reason and for safety, a push pin and a small
hammer are the preferred tools of young hands. However, push pins
shafts are thicker than needles, typically 1 mm (0.040 in) in
diameter, thus they make a larger hole and the fuel doesn't burn as
cleanly. If you use a push pin make 24 holes instead of
32.
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[FIGURE 4]
[FIGURE 5]
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STEP 2. FORM THE LARGE CENTRAL HOLE
(Fig. 4)
Summary. Concentric with the circle of burner
holes you made in STEP 1 is a raised circular ridge. Inside the
ridge is a bowl-shaped area about 45 mm (1 3/4 in) in diameter. Use
a utility knife to cut out the bowl at the base of the circular
ridge, but leave the circular ridge and its sides intact. Round the
rough edge of the hole with a half round file and smooth it with
fine sand paper.
Details. To cut the large central
hole with a utility knife, arm the utility knife with a keen (not
dull) sharp point (not round point) blade. A dull blade may damage
this section of the stove. Hold the can firmly, bottom side up on a
hard, flat surface. Score the aluminum can at the base of the
circular ridge all the way around its circumference (Fig. 5). On the
first pass use very light pressure to obtain a smooth circle. After
the first complete turn, continue the process 3-6 more times with
light to moderate pressure (never heavy pressure) until the
bowl-shaped area of the can pops out.
Tip. With a sharp blade and good
technique there is no need to push the blade through the aluminum.
Nevertheless, in difficult cases you may find it advantageous to
push through the well scored circle with the tip of the blade making
a 3 mm (1/8 in) long slit, or if necessary, several consecutive
slits to form a longer slit. While making the last slit (the first
could be the last), the bowl-shaped section will pop out or drop
down with a tearing sound. If it drops down but doesn’t pop out, rap
in the center of the circle with the base of the utility knife
handle, but don't rap so hard that you bend the can.
Shape the large central hole to the base of
the circular ridge with a half round file (smooth cut). Smooth the
edge of the hole with 320 to 500 grit sand
paper.
Tip. Place the
can bottom side up on a hard, flat surface and file vertically.
Remove material right up to the base of the ridge. Then, use your
fingers to gently bend the remaining thin aluminum edge up into the
large central hole so that it can be filed off in the opposite
direction (i.e., reverse the file).
Tip. When
cutting, filing or sanding, hold the can high at the end to avoid
putting a permanent dent in the weak side walls of the can
particularly within 25 mm (1 in) of the burner holes. Exert downward
pressure toward the opposite end, not inward pressure toward the
center.
Tip. Save the cut out aluminum “bowl” for
mixing epoxy.
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[FIGURE
6]
[FIGURE 7]
[FIGURE
8]
[FIGURE 9]
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STEP 3. CUT OUT THE TOP SECTION (Fig.
6)
Summary. Cut out the top section of the stove with
a utility knife blade or scissors so that the finished height is 22
mm (7/8 in). The height of the top section is not as critical as the
bottom section and inner wall. The suggested range is 20-24 mm
(13/16-15/16 in). Use fine sand paper to prepare the interior
surface of the sidewall for epoxy. Clean with warm water. If and
only if the bottom section of the stove will be made from a 12 oz
can, cut 8 vertical evenly spaced slits in the side wall to a depth
of 3 mm (1/8 in) from the shoulder of the can. Burnish the
slits.
Details. Two methods are given for cutting the
aluminum can. Each works well, but practice on spare cans before
cutting the real stove top.
To make an even cut with a sharp
point utility knife blade, hold the blade horizontal and steady 22
mm (7/8 in) in height above a flat surface, such as a table top. The
blade can be trapped in a hard cover book (Fig. 7) or fixed to a
block of
wood. A blade with a hole in the
middle is easy to secure to the top of a block of wood with a screw
and a brad or two. To hold the blade in a book, tape the blade to a
stiff piece of paper or thin cardboard, insert the cardboard between
the pages of the book, and close the cover. When scoring the can,
push down firmly on the book with even pressure to lock the blade in
space. By block or by book, the point of the blade extends about 10
mm (3/8 in) past the edge. Place the PepsiCo can bottom down on a
hard, flat surface. Bring the point of the blade in contact with the
can and the side of the can in contact with the block or book.
Rotate the cutting tool (wood block method) or rotate the can (book
method) so that the blade scores the can (Fig. 7). Repeat for about
3 to 5 complete rotations until the can is well scored. Apply gently
pressure to the side of the can so that you don’t put a permanent
crease in the can or pierce through the can with the blade. When the
can is well scored, take the utility knife and cut through the side
of the can all the way around its circumference far enough above the
score line that you don't dent the can below the score. A couple of
centimeters (1 in) above the score line is usually sufficient. From
the edge of the new cut, use scissors or a utility knife to cut
toward the score at a 45 degree angle until within about 3 mm (1/8
in) of the score. Grab a corner where the last cut was started and
tear the aluminum along the score all the way around the can. Tear
the aluminum by pulling outward, i.e., away from the center of the
can.
Alternatively, cut the can with strong scissors. First
draw a line around the entire circumference of the can with a
marking pen (Fig. 8). Keep the marker stationary while you rotate
the can about its long axis with its bottom on a flat surface. To
keep the marker stationary, use a piece of cardboard with a hole
punched in it to insert the marker tip. Actually the cardboard
should have two holes, one 22 mm (7/8 in) from a straight edge and
one 28.5 mm (1 1/8 in) from a straight edge for the top and bottom
sections, respectively. Take the utility knife (including the
handle) and cut through the side of the can all the way around its
circumference far enough above the marked line that you don't dent
the can below it. A couple of centimeters (1 in) above the line is
usually sufficient. From the edge of the new cut, use scissors to
cut toward the line at a low (acute) angle. Approach the line
slowly. It may take 5 or more complete revolutions to finish the cut
and the last revolutions may trim off 1 mm at a
time.
Tip. The stove
looks best if the height is consistent around the entire
circumference. To check the height, place the stove top upside down
on a flat surface and hold a ruler vertically next to the can.
Rotate the can and check the height of the cut edge against the
ruler.
Lightly sand the interior
of the side wall of the top section with 320 to 500 grit sandpaper.
This prepares the surface for J-B Weld (see STEP 6). You can also
sand the cut edge of the top section, but if you care about stove
cosmetics and you aren’t going to cover the stove exterior with tape
(see STEP 9) then don’t sand the outer surface.
Clean metal
particles and dried soda from the top section, especially that in
the groove, with warm water from a faucet. A bottle brush or old
toothbrush is helpful.
If you plan to use a 12 oz can for the
bottom section instead of a 14.9 oz Irish beer can, cut vertical
slits in the sides of the top section of the stove with scissors.
The slits start from the cut edge of the top section and end 3 mm
(1/8 in) from the shoulder (rounded edge) (Fig. 9). Make 8 slits
evenly spaced around the circumference of the can. Burnish the slits
with a hard, rounded object such as an old spoon, a coin, or the
handle of a felt-tipped pen to close up the slit and smooth it. This
is done by holding the top section sideways on a hard, flat surface
so that the length of a slit contacts the flat surface, and rubbing
the slit on the inside of the top section.
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[FIGURE 10]
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STEP 4. CUT OUT THE BOTTOM SECTION (Fig.
10)
Summary. The bottom section of the stove is made
from a 14.9 oz can of Guinness Draught, Caffrey’s Irish Ale, or
Murphy’s Irish Stout. Cut the bottom section 28.5 mm (1 1/8 in) in
height. The height of the bottom section is important. It should be
within the range of 27 to 30 mm (1 1/16 to 1 3/16 in) around the
entire circumference. Use fine sand paper to prepare the upper third
of the side wall exterior surface for epoxy. Clean with warm
water.
Note: A 12 oz
can (preferably one that matches the top section) may substitute for
the 14.9 oz Irish beer can, but you must cut slits in the top
section as described in the last paragraph of STEP 3.
Details. Cut the bottom section
following either the utility knife blade or the scissors procedure
of STEP 3 and the tips below.
Tip. Check the height with a ruler. Place
the stove bottom right side up on a flat surface and hold a ruler
vertically next to the can. Rotate the can and check the height of
the cut edge against the ruler. Actually, I make my 14.9 oz Irish
beer stove bottoms 30 mm (1 3/16 in) and my 12 oz stove bottoms 27
mm (1 1/16 in) tall.
Tip. If you are careful not to
dent the unused portion of the aluminum can, you may use it to make
the inner wall of the stove (STEP 5). Otherwise you will need an
extra undented, generic aluminum can.
Lightly sand the cut edge of the bottom section
and the upper 1/3 of the exterior surface of the side wall with 320
to 500 grit sandpaper. This facilitates stove assembly and bonding
of J-B Weld, respectively. Clean the bottom section with warm
water.
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[FIGURE 11]
[FIGURE 12]
[FIGURE 13]
[FIGURE 14]
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STEP 5. MAKE THE INNER WALL OF THE STOVE
(Fig. 11)
Summary. From the remainder of the Irish beer can
(or a spare 12 oz can) fabricate a rectangular band 35 mm (1 3/8 in)
wide and 180 mm (7 in) long (Fig. 12). The width of the rectangular
band is important. The acceptable range is 34-36 mm (1 11/32-1 13/32
in). The length is less important. It can be 170-180 mm (6 11/16 to
7 1/16 in). Form 3 gaps along one of the long edges, each 2.5 mm
(3/32 in) deep. The center gap is at the midpoint of the edge and
the other two gaps are 50 mm (2 in) from it. Opposing slits, 150 mm
apart, are optional and are explained in the Note at the end of STEP
5.
Note: If you use a
14.9 oz Murphy’s Irish Stout can or any 12 oz can for the bottom
section (STEP 4), make the rectangle 38 mm (1 1/2 in) wide and the 3
gaps 5 mm (3/16 in) deep.
Overlap
the short sides of the rectangular band to form a cylinder that fits
snugly into the circular groove of the top section. Use tape and/or
Krazy glue on the outside surface to temporarily bond the cylinder
together. Follow with a thin bead of J-B Weld over the external tag
end of the band to permanently cement the
cylinder.
Details. Use a utility knife to cut off the
remaining end (the top) of the Irish beer can, or the top and bottom
of a generic can, about 2.5 cm (1 in) from the end(s) so that you
have a cylinder with ragged edges. With scissors, cut vertically
straight across the cylinder to form a ragged rectangle. Lay the
aluminum down on a cutting board and place a straightedge on top
parallel to a long side. Trim off one ragged long side with the
utility knife using the straightedge as a guide.
Tip. When cutting the aluminum with the
straightedge and utility knife, score the aluminum lightly and
repeat several times. Hold the straightedge firmly in place and bend
the aluminum at the score upright 60 to 90 degrees and then back
down. Repeat this bending process until the aluminum breaks off
evenly at the score.
Measure 35
mm (1 3/8 in) from the new smooth edge and repeat the cut to form
the opposite long side. The long sides should be as parallel as
possible. You now have a long rectangle. Call it a band. Trim one of
the short sides of the band perpendicular to the long sides. Cut the
other short side 180 mm (7 in) from its opposing side.
To
allow the alcohol fuel to flow from the middle of the stove to the
space between the walls, make three gaps along one of the long edges
of the band. One gap is at the midpoint of a long edge and the other
two gaps are 50 mm (2 in) out from the midpoint. Mark their location
with a marking pen. Form arch-shaped gaps by using a hole punch set
in from the edge about 40% of its diameter or 2.5 mm (3/32 in)
deep.
Alternatively, if you don’t have a hole punch, make the
gaps with scissors or a utility knife. To form a rectangular gap,
cut two slits perpendicular to the long edge of the aluminum band
2-3 mm deep and 3 mm apart. Bend the aluminum between the slits flat
against the painted side of the band.
Wipe the surface of all
three stove parts with tissue paper soaked in denatured alcohol.
Denatured alcohol removes marking pen ink as well as cleans the
surface for bonding of J-B Weld.
Convert the inner wall band
into a cylinder as follows. Pull off a 2 cm (3/4 in) piece of
masking tape and set it aside. Place the top section of the stove
upside down on a flat surface. Overlap the ends of the band about 30
mm (1 3/16 in) to form a cylinder. Seat the cylinder into the
circular groove of the top section. Tighten the cylinder, making
sure it remains fully seated in the groove. Holding the area where
the ends of the cylinder overlap, carefully remove the cylinder
without changing its diameter. Make sure the overlapped edges of the
cylinder are even and place the piece of masking tape on the outside
of the cylinder across the tag (free) end (Fig. 13).
Check
the diameter of the cylinder as follows. Reinsert the cylinder,
overlapped area first, into the circular groove. The cylinder should
fit snugly in the groove but not tightly. In other words, it should
take a little force, say 0.5-1 kg (1-2 lb), to push the cylinder
into the groove but it should not take so much force that the
cylinder goes out of round. Adjust the diameter of the cylinder
until it is correct. If the cylinder is close to the right diameter,
small adjustments of 0.5-1 mm make a difference. A snug cylinder
makes stove assembly (STEP 6) easier and properly directs vaporized
fuel out the burner holes. A cylinder that is too tight may buckle
during stove assembly. When you are satisfied with the cylinder
size, glue down the tag end on the outside of the cylinder with a
drop or two of Krazy glue.
Tip. Place two small pieces of masking
tape across the top and bottom edges of the cylinder in the middle
of the overlap. Remove the original piece of tape from the tag end
on the outside surface of the cylinder and apply Krazy glue under
the tag end.
After the Krazy glue
bonds (10-15 sec), remove the tape. To prepare the surface for J-B
Weld, lightly sand the tag end on the outside of the cylinder and a
few mm on either side of it. Retest the cylinder diameter by fitting
it into the circular groove of the stove top so that the edge
WITHOUT the gaps is in the groove. If it fits snugly, leave it in
the groove. If the cylinder fits loosely see STEP 7 for how to
correct a loose fit. If the fit is too tight break the Krazy glue
bond with heat and readjust the cylinder diameter, or make a new
cylinder.
Use a wooden match stick or toothpick to apply a
thin bead of J-B Weld about 3 mm (1/8 in) wide covering the edge of
the tag end on the outside surface of the cylinder. Allow the J-B
Weld 5 hr or more to partially cure before proceeding with stove
assembly (STEP 6), or immediately proceed with stove assembly being
careful not to touch the uncured epoxy.
Note. J-B Weld is necessary because the
heat produced during stove operation loosens the Krazy glue bond and
the cylinder would otherwise unravel. If you choose to let the epoxy
cure before proceeding you might as well apply the epoxy with the
cylinder unattached to the top section. It’s easier that
way.
Note. In the first version of the Pepsi Stove
instructions, the cylinder was held together with two interlocking
slits rather than J-B Weld. This design is stronger than the one
above, though more difficult to execute because precise slit
distance is critical to obtain a snug fit. [See STEP 7 for how to
seal a loose fit.] Slit instructions are repeated here for those
that prefer them. Measure 15 mm (5/8 in) in from one of the short
sides of the rectangle and cut a slit into one of the long sides of
the rectangle. Slit depth is slightly more than half the length of a
short side, or 18 mm (3/4 in) for a 35 mm (1 3/8 in) wide band. Make
the slit as perpendicular to the long sides as possible. Measure 150
mm (5 29/32 in) parallel to the long sides and make the second slit
in the edge of the opposite long side. Interlock the two slits of
the long rectangle to make a cylinder so that the tag ends are
outside the cylinder (Fig. 14). Tape down one of the tag ends with a
small piece of masking tape, making sure the edges of the tag end
are even with the edges of the cylinder. Glue the untaped tag end to
the outside of the cylinder with a drop or two of Krazy glue, making
sure the edges of this tag end are even with the edges of the
cylinder. Remove the tape and glue down the free tag end. Seal the
interlocking slit and affix the two tag ends with three parallel
thin beads of J-B Weld on the outside surface of the cylinder. Allow
the J-B Weld 5 hr or more to partially cure before proceeding with
stove assembly (STEP 6), or immediately proceed with stove assembly
being careful not to touch the uncured epoxy.
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[FIGURE 15]
[FIGURE 16A]
[FIGURE 16B]
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STEP 6. ASSEMBLE THE STOVE (Fig.
15)
Summary. Fit the gapless edge of the inner wall
into the circular groove of the top section. Slide the bottom
section inside the top section. When the bottom section barely fits
inside the top section, apply a thick bead of J-B Weld around the
entire circumference of the bottom section just below the edge of
the top section. Compress the sections together until the inner wall
is tightly trapped between the top and bottom sections. Wipe off the
excess epoxy. If the top section has slits, install rubber bands to
compress the slit sides. Invert the stove and put a weight on top.
Cure for at least 5 hr.
Details. Before assembling the
stove, make a rectangular shim from aluminum can scraps to help ease the top
section over the bottom section. From the side of an aluminum can
cut out a rectangle about 25 x 65 mm (1 x 2 1/2 in). Round off the
corners of the rectangle and lightly sand the edges. The shim should
be smooth and undented particularly along its edges. Save the shim
for ensuing stoves.
If you haven’t done so already, insert
the cylindrical inner wall into the circular groove of the stove top
so that the edge without the gaps is in the groove.
Place the
top section (with the inner wall held in its groove with friction)
over the bottom section and angle the top section so that one part
of its edge overlaps the edge of the bottom section by about 3 mm
(1/8 in). Fix the two sections together at that point with a short
piece of tape, about 40 mm (1 1/2 in) long (Fig. 16A). On the side
of the stove opposite the tape insert the shim between the edges of
the top and bottom sections (Fig. 16B). Move the shim along the
junction of the edges right to left (or left to right) as needed to
ease the top section over the bottom section.
When the edge
of the top section barely overlaps the edge of the bottom section
around the entire circumference, remove the shim and the tape and
press the two sections together slightly so that they overlap by 6
mm (1/4 in) or less. Apply a thick, continuous bead of J-B Weld
about 10 mm (3/8 in) wide around the entire circumference of the
bottom section just below the edge of the top section. Press the top
and bottom sections together slowly until the inner cylinder is held
firmly between the top and bottom sections. During this compression
process, make sure the cylindrical inner wall is seated in the
circular groove of the top section and keep the straight side walls
of the two sections as parallel as possible. As long as you do, the
stove should easily withstand 2-4 kg (5-10 lb) of vertical force.
When the inner wall is flush against the bottom of the bottom
section and the stove does not compress any further with moderate
pressure, stop. Don’t compress the stove with so much force that you
bend the inner wall. The stove should be 40 mm (1 9/16 in) in
height.
Note. The
circular groove on the bottom of a Guinness or Caffrey’s can has a
larger diameter than the circular groove of a PepsiCo can, thus the
cylindrical inner wall won't fit into the groove of a Caffrey’s or
Guinness bottom stove section. This is not a problem. Ignore it. On
the other hand, the circular groove of the Murphy’s can is
approximately the same diameter as the PepsiCo can, thus the
cylindrical inner wall fits into the circular groove of the Murphy’s
can.
Thoroughly wipe off the
excess epoxy with paper towels, facial tissue, or toilet paper. Keep
the epoxy off your fingers so that you don't transfer it to the
burner holes.
Note:
If the top section has slits be careful not to bend them when wiping
off the epoxy. Once the excess epoxy is cleaned up, put several
rubber bands around the stove to clamp the slit sides of the top
section against the outside of the bottom section.
Invert the stove, put a weight on top (e.g.,
can of soup) and let the epoxy cure for at least 5 hr before
proceeding to STEP 7 or at least 15 hr before proceeding to STEP
8.
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[FIGURE 17]
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STEP 7. SEAL THE TOP SECTION (Fig.
17)
Summary. Use J-B Weld to seal the three potential
sites for flame leaks: 1) the junction of the top edge of the inner
wall and the circular groove, 2) under the circular edge of the top
section on the side wall of the stove, and 3) the 8 vertical slits
in the top section. Skip STEP 7 if the inner wall fits snugly in the
groove of the top section and you are not a perfectionist, if the
top and bottom sections are undented and generously bonded with J-B
Weld, and if the top section does not have
slits.
Details. If the inner wall fit loosely in the
circular groove of the top section or you are inescapably
meticulous, seal the gap between the top of the inner wall and the
circular groove. Use a wooden match stick or toothpick to scrape J-B
Weld into the space between the top of the inner cylinder and the
lip of the circular groove. Use Q-tips to force the J-B Weld into
the gap, smooth out the epoxy, and remove most of the excess epoxy.
Use paper towels, facial tissue, or toilet paper to thoroughly wipe
off excess J-B Weld from the inner cylinder. If further sealing is
planned, immediately proceed to the next paragraph. Otherwise, let
the epoxy cure for at least 15 hr before using the stove.
If
the top and bottom sections are dented and/or J-B Weld was used
sparingly to bond these two sections together, then there may be an
air gap for a flame leak. Put a bead of J-B Weld over the circular
edge of the top section on the side wall of the stove, and try to
force epoxy under the edge with a Q-tip. Wipe off the excess epoxy.
Immediately proceed to the next paragraph if your stove has slits in
the top section. Otherwise, let the epoxy cure for at least 15 hr
before using the stove.
If you cut slits in the top section
of the stove, seal each slit with a thin bead of J-B Weld about 2 mm
(3/32 in) wide. Use a wooden match stick or toothpick to apply the
epoxy. Let the epoxy cure for at least 15 hr before using the
stove.
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[FIGURE 18]
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STEP 8. TEST THE STOVE (Fig.
18)
Summary. Test the stove for proper operation and
flame leaks.
Cautionary
Note: Perform this test is subdued light. An alcohol flame is
nearly invisible in bright light. When the flame burns out, let the
stove cool for a couple of minutes before touching it with bare
fingers.
Details. Put 250
ml (1 cup) of water in a cooking pot and set it aside. Set the stove
on a heat resistant surface such as a dinner plate or pie tin. Pour
about 15 ml (1 T or 0.5 fl oz) of denatured alcohol or methanol down
the large central hole of the stove and light it. It takes about a
minute for this volume of room temperature alcohol to heat up,
vaporize, and achieve an even burn out the burner holes. Hold the
pot about 2.5 cm (1 in) above the flame. You should observe an even,
circular pattern of (mostly) blue flame coming out of the small
burner holes. If the flame doesn’t come out of the burner holes you
likely have a problem with the inner wall. Either it is too loose or
the gaps are blocked off. If the inner wall is too loose seal it at
the top with J-B Weld (see STEP 7). If you can’t rotate the inner
wall with your fingers it is not too loose. If the gaps are blocked
off, punch or cut holes at the base of the inner wall. If you can
see the gaps they aren’t blocked off. A predominantly orange flame
indicates poor fuel quality or poor oxygenation of vaporized
fuel.
Note: Without a
pot over the stove, it appears to the novice that the flame burns
excessively high. Further, it may appear that the flame comes
largely out of the central hole, but that is an optical illusion
unless it happens with the pot test.
Put the pot down and check for flame leaks at the
junction between the top and bottom sections of the stove and at the
slits in the top section (if there are any). Rotate the plate to
check the entire circumference of the stove. If there is a flame
leak seal it with J-B Weld. Let the epoxy cure for at least 15 h
before retesting the stove.
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[FIGURE 19]
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STEP 9 (Extremely Optional). FINISHING
TOUCHES (Fig. 19)
Summary. Some artisans may want to
befuddle their buddies and beautify their burner by disguising the
graphics and junction of the top and bottom sections with heat
resistant tape.
Details. Pull 30 cm (12 in) of 3M High
Temperature Flue Tape off the roll and cut the 1 1/2 in wide tape in
half lengthwise. This produces two pieces of tape about 20 x 300 mm
(3/4 x 12 in), which is enough for two stoves. Trim a couple of
centimeters (1 in) from each end to have a clean, wrinkle-free
piece. Center the tape on the side wall of the stove and tape over
the junction of the top and bottom sections. As you install the
tape, burnish it by rubbing with your thumb, but don't push too hard
and put a dent in the stove. The tape can be removed at any time
with no damage to the stove and the tape residue cleaned off with
denatured alcohol or acetone.
Alternatively, install heat
resistant, self-adhering silicone tape. One brand is Tommy Tape. It
comes in a variety of widths, but be aware that Tommy Tape should be
stretched during installation so it becomes 25% narrower than it is
on the roll. Consequently 3/4 in wide tape becomes 9/16 in wide
installed and 1 in wide tape becomes 3/4 in wide installed. Tommy
Tape comes in a variety of thicknesses and two cross-section shapes.
I recommend the 20 mil thickness and rectangular cross-section. The
regular colors are dull but vibrant colors will soon be offered. If
you are lucky you can find the tape in a local retail store. If not,
order it from tommytape.com. If you are hesitant to take the
plunge for a 10 or 36 ft roll, they offer a 3 ft evaluation roll for
$1.95 (including shipping), but be warned, the tape is tricky to
work with because it is self-adhering and you may waste 3 ft just
learning how to handle it. One downside of this tape is that dirt
and sand tend to stick to the tape like they do to a silnylon tarp.
Cut 30 cm (12 in) off the roll, which should be enough for 2+ turns
around the stove. Trim the corners off both ends. Center the
starting end on the side wall of the stove and hold it there tightly
as you stretch and wrap the tape around the stove. The tape sticks
to itself but it doesn’t stick to the stove, thus you can roll the
tape off if you want to remove it.
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[FIGURE 20]
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STEP 10 (Optional). MAKE A SIMMER RING
(Fig. 20)
Summary. The simmer ring is made from the top of a
24 oz Miller beer can. Enlarge the pop top hole with a file. Tear
the side wall of the can away from the top. Press (or hammer) the
top surface of the can top downward against a flat surface to form a
cake pan shaped simmer ring.
Details. Wiggle the pop
top back and forth until it falls off. Enlarge the hole with a half
round and/or a round file, and smooth the edge of the hole with fine
sandpape.
Note: You
may find with experience that you want a larger opening than the pop
top makes. The prospective simmer ring pictured in Fig. 20 has a
slightly enlarged hole. It is easier to enlarge the opening before
releasing the top from the can.
Release the flat can top from the rest of the can
by cutting the side wall of the can all the way around the perimeter
about 2-3 cm from the top. From the cut edge of the side wall, cut a
slit down to within a few mm of the flat can top. Tear the side wall
away from the top, which resembles a miniature pie plate. If the
flap that covered the hole is still attached to the back, pull it
off. Do not bend the top while removing the side wall
material.
Place the can top right side up (rim up) on a flat,
hard surface. Pound down, or better, press down the horizontal
portion of the can top until it is flat against the flat, hard
surface. Do not bend the circular rim portion of the can top or its
short horizontal sides. That’s all. You now have a simmer
ring.
Tip. A solid
cylinder (metal, plastic, or wood) with parallel faces helps in this
procedure, especially if the diameter of this cylindrical tool is
slightly smaller than the diameter of the can top rim so that the
cylinder fits snugly inside the can top.
The simmer ring is typically used after the
dinner has come to a boil. Place the simmer ring upside down on top
of the large central hole of the stove. The outside edge (or rim) of
the ring should cover the burner holes which forces the alcohol
flame to come out the hole of the simmer ring. It takes a minute or
so for the flame to come to a new low flame equilibrium. If you want
to switch back to high heat, then simply remove the simmer ring. If
you want to extinguish the flame, it is easier to blow out if the
stove with the simmer ring in place. Let the stove cool and pour any
remaining fuel back into the fuel bottle.
Be careful. The
simmer ring gets too hot to touch with bare fingers. You can place
or remove the simmer ring with multi-tool pliers, alligator clips, a
spork, or a stick. Alternatively, you can install a mini handle made
out of lightweight material attached with J-B Weld or a
rivet.
Note: Set up
the stove in an area protected from the wind and use a windscreen.
This is especially important for this simmer ring
design.
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STEP 11. MAKE A POT STAND AND
WINDSCREEN
Instructions for pot stands and windscreens are
already well described on the internet. Below is a suggested
link.
Roy
Robinson’s Cat Stove
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