OUTDOORS DIY
E
HEAT SOURCES
An electric
heating gun/
paint stripper
has enough power
to heat the balloon
for short test hops
in the backyard,
and it helps inflate
the envelope while
heating. Other heat
sources, such as multiple cans of Sterno
grouped beneath a short metal chimney,
may be experimented with.
F
But the classic wastepaper/stovepipe
burner provides maximal heating for this
balloon. You can make the burner from a few
feet of 6" stovepipe and a firebox made from
an aluminum register box, a ductwork elbow,
or scrap sheet metal. Black steel or aluminum
is best, as galvanized steel ducting produces
unhealthy zinc-oxide dust when exposed
to flame. The burner shown here has a fire-
box fashioned from scrap aluminum flashing
and a large cookie tin, riveted together in
about 10 minutes.
ties (Figure D). Don’t use wire for the hoop (in
case the balloon runs afoul of power lines), or
wooden doweling (it snaps and splinters).
Gather the other end of the cylinder as
evenly as possible, wrap it around the hoop
from the outside inward, and tape it every few
inches to form a hem a few inches up inside
the bottom of the balloon (Figure E).
Fit the firebox to
the bottom of the
pipe and place
a piece of screen
over the top of
the chimney to
prevent burning
bits of paper from
escaping.
4. Check for holes.
Inflate the completed balloon by holding the
open end in front of a small fan (Figure F).
Identify any holes and tape them. Tie the
tether line to the hoop and secure it with tape,
or use kite line attachment links if you wish. ;
Jesse Brumberger is a mechanical engineer of 25 years
experience and a graduate of Syracuse University. He enjoys
building and making all sorts of things, from model aircraft to
precision-machined miniature running engines.
Unless you’re flying on a steel wire
in the middle of
nowhere, it should
not need saying
that a heat source
should never be
sent aloft on a
balloon.
Zachary Brumberger (bottom sidebar, opposite)
136 Make: makezine.com/29
