Curtis Dyna-Fog BLACKHAWK 2620, Instruction Manual

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On a dry fog setting, which must always be employed indoors and in confined areas, the ignition
source must be continuous since the fog will not continue torching except briefly if the ignition source
is removed. On a wet fog setting, it is possible for the fog to continue to torch after removal form the
ignition source. Never use a wet fog setting indoors and in confined spaces. Extreme caution must
be exercised when using a wet fog setting under any circumstances. A wet fog setting can leave a
deposit of liquid on combustible surfaces creating a fire hazard should torching take place.
A second source of fog ignition can be the machine itself. If the machine stops running for
any reason, including the exhaustion of fuel, the operator must quickly rotate the 3-way valve to the
purge position to stop the fog discharge. If the engine stops, it is possible for some formulation to
flow into the still hot engine tube where it will vaporize. Part of this vapor may then be drawn by
natural thermal convection back through the annular cooling air space between the cooling duct and
the engine tube, to the red hot engine combustion chamber. If the proportion of vapor to air is just
right when this occurs, the vapor will ignite and flash back through the discharge end of the engine
tube, igniting the small amount of formulation which may continue to flow very briefly. Burning
formulation can then drip briefly from the discharge end of the cooling air duct. If this burning
formulation comes into contact with an easily combustible material or a surface which has
accumulated a substantial deposit of liquid formulation, a fire could result.
5. Safety Equipment. Many of the formulations which can be dispensed with this machine
are highly toxic and require special safety equipment. The formulation label should specify all safety
precautions with respect to the formulation. Read and observe the procedures, cautions and
WARNINGS on the formulation label. Proper ear protection should also be worn when operating this
machine.
6. Improper Operation. There is no substitute for good maintenance practices. An engine
with excessive carbon deposits will run weakly and is likely to stop at any time. A weak running
engine will also emit extremely wet fog at lower rates of formulation flow and this can result in
surfaces rapidly becoming coated with the formulation, and thus help to feed a fire if ignition takes
place as described above. Refer to the MAINTENANCE section for cleaning instructions.
7. Improper Use. Never place the discharge end too close to a wall or other obstruction.
The engine is maintained at the proper temperature by cooling air aspirated (pumped) by hot gases
flowing out the discharge (exhaust) end of the engine. If this cooling air flow is prevented, the
machine will overheat and it can suffer permanent damage which could result in an explosion or fire.
Maintain at least 24 inches (61 CM) clearance between the engine discharge (exhaust) and external
objects.
8. Machine Damage. Never operate a machine after it has been damaged. A damaged
machine can be a fire hazard.
9. Wind. Fogging during windy conditions is not usually practical because the formulation
will drift out of the intended area. However, under no circumstances should fogging INTO the wind
be attempted. Should the machine stop running for any reason, and a wind gust force vaporized
formulation back against the hot combustion chamber, it could ignite and flash back causing
momentary flaming from the discharge (exhaust) end of the machine.
10. Children. Many fogging operations are performed in residential areas commonly at dusk.
This presents the operator with the problem of children who are attracted to the fog. Children have
been observed running into and riding bicycles through the fog. Once in the fog, they cannot see or
be seen. In some reported instances, a child has been injured by running into an object obscured by
the fog. Also there is a possibility of fire should the machine briefly flame or become ignited from an
external source. Still another possible hazard lies in the toxic effect of the formulation, the severity of
which depends upon the chemical used, fog density, and the length of time of direct exposure.
IT IS THE OPERATOR’S RESPONSIBILITY TO DISCOURAGE ANYONE FROM PLAYING IN
THE FOG.
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