Weather balloons are generally made out of natural latex rubber. The balloon when inflated can expand to several times its natural size without rupturing. Typically they are rated by the weight of the balloon. Smaller balloons start from about 300g weight and the larger ones can go upto 1.5Kg.
When calculating the amount of helium this is important. The helium has to lift the weight of the balloon as well as the payload. Failure to account for balloon weight can seriously affect the range and altitude the balloon achieves.
Choosing a balloon size should be dependent on the payload weight. We will show how to do this in later sections.
When making a purchase for your flight, keep the following things in mind.
- Make sure that the balloon is not too yellowed out. Latex rubber is naturally white. When the material is exposed to the environment and light, it slowly yellows out. Too much yellow can be an indicator of old balloon stock and should not be purchased
- There is a lot of talk about handling balloons with your bare hands. Touching the balloon with your hand does not spoil the balloon, and most people the author has talked to dont seem to think it matters.
- When handling the balloon, make sure your hands are clean and nails are trimmed. The material is easy to tear. Also lay it out on a clean tarp when inflating it.