The ultimate buoyant treat for any special occasion, balloons have been a cherished part of birthdays, weddings and other events since "Little House on the Prairie" inflated pig stomachs. Gross, but it shows how far people will go for the simple brilliance of a balloon. Unfortunately, nothing lasts forever. Eventually, the helium will leak out and your balloon will sag to the ground, a mere husk of its formerly joyous presence. That's not to say that there's nothing you can do. In fact, there are quite a few small tips that can greatly extend the life of your balloons.
Pre-inflate with air before using valuable helium. Not only will this ensure that no helium is being spent on a defective balloon, pre-inflating can also aid in a balloon's longevity. By first inflating with air, the balloon is stretched, ensuring that when helium is used, the balloon is filled to a taut capacity that won't droop over time.
Store balloons in a trash bag before and after use. The main contributor to the gradual loss of a balloon's structural integrity is the air around it. Dirt, dust, and even wind will weaken the balloon's mylar or latex surface. Oxygen is very corrosive, slowly eating away at your balloon's skin. While there is no way to keep the balloon from air entirely, storing balloons in a garbage bag can help slow the natural decay.
Use Hi-Float or Super Hi-Float if you are really desperate to keep those balloons in the air. The former coats the outside of the balloon and prevents the surface from oxidizing. The latter, Super Hi-Float, is a gel that is sprayed inside a balloon before inflation. In some circumstances, coating the balloon's inside with Super Hi-Float can extend its lifespan by a matter of weeks.
Inflate your balloons at the same temperature as their intended use. This way a proper inflation will be perfect for your event. For example, if you anticipate being outside on a chilly day with your balloons, consider inflating them in a cool garage.
Coat your balloon to extend its lifespan. Coating the outside surface with a silicone spray, or even hairspray, can help firm up the surface and seal off slowly dissipating leaks.