Considering how much time and money it takes to fill them, the least your helium balloons could do is stay afloat for the entire party. Alas, it seems that these balloons are never inclined to cooperate and end up bobbing along near the floor before the last guest has left. What is the best way to keep helium balloons inflated for longer than an afternoon? It's all about choosing the right materials.
Prepping Helium Balloons
As is true of so many other things, with balloons, you tend to get what you pay for. Cheap balloons are prone to leaks, so they'll deflate quickly no matter what you do. The best option is to buy balloons from a party-supply store where you can compare options and ask for advice if necessary.
Material is also an important consideration. The two common types of helium balloons sold to consumers are Mylar and latex. Mylar balloons, also known as foil balloons, are nonporous, so they hold helium for longer than latex balloons. Mylar balloons may stay inflated for several days, while helium balloons often wilt within a day. The downside is that Mylar balloons are more expensive, will never decompose and tend to require more helium.
If you are filling your own balloons with helium, be mindful to not overinflate them. Overinflated balloons won't float as long as they could. Aim for an egg shape with standard latex balloons; a balloon that's shaped like a pear or light bulb is overinflated. Make the knot as tight as possible and if you're adding a ribbon, tie it below the knot so as not to weaken the stretched material.
Caring For Helium Balloons
Some people spray hair spray on their helium balloons, creating a protective outer layer to prevent leaks. Only attempt this if your balloons will be decorative only. A balloon coated in hairspray shouldn't be handled, or it may shrivel.
Once they're blown up and ready to display, the best way to keep helium balloons inflated is to keep them in a climate-controlled room. Extremes in temperature will cause them to deflate. Exposure to direct sunlight and extreme heat may also make balloons pop suddenly. If you're using balloons for an outdoor gathering, choose light colors (they won't absorb sunlight the way darker colors do) and keep them outdoors for only as long as necessary.
Best Way to Keep Helium Balloons Inflated
When you want the look of latex balloons but they absolutely have to last for more than a day, the best way to keep helium balloons inflated is to use a product called HI-FLOAT. It's a liquid material that coats the inside of an empty latex balloon before it's filled, keeping helium from escaping. The company that makes HI-FLOAT says that using the product can extend the life of a balloon by 25 times, so balloons filled this way can actually be inflated a day ahead of an event.
Using HI-FLOAT adds a little extra time to your balloon-filling process. A nozzle is inserted into each balloon, and a precise amount of the liquid is squirted inside. Then, the balloon has to be rubbed to carefully disperse the liquid without getting any in the neck before it can be filled with helium. This product is available at party-supply stores.