When the balloon has the desired amount of gas, it will lift the nozzle shutting off the hydrogen generator. Close the valve on the tank first. Next, push down on the free-lift nozzle to purge the remaining gas out of the line. Then, close the regulator valve. Turn off the hydrogen power switch outside the building.
Tie the long, looped string attached to the top of the parachute around the neck of the balloon. Secure it tightly, but be careful not to cut the balloon neck. It is recommended to wrap the string a couple times around the neck to ensure the balloon is closed and no gas escapes. Tie another knot to finish. Place the remaining loop on the clip to hold the balloon in place (Figure 1.6).
Figure 1.6—String on clip to hold down balloon.
Remove the retaining clip and remove the balloon from the nozzle. Fold the bottom of the balloon neck up and secure it with the short length of string that was cut earlier. Tie a knot. It is recommended to wrap the string 3-4 times around the neck and finish by tying a square knot (Figure 1.7).
Figure 1.7—Securely tie up the balloon neck.