Helium will disappear in a balloon over a few hours. If a closed container is filled with helium will it stay active and for how long? I need to float a duck house in a pond, using atmospheric air pressure will not support it. Will a 4 inch x 10 foot pvc pipe filled with helium instead of air possibly float it? Not knowing the weight of the house and platform I can't give numbers to calculate by, so how much weight will a 4"x10ft pvc pipe closed and sealed air/water tight float? And for how long?
Responses (1)
Helium does not disappear, it slips between the molecules of the balloon and rises into the sky. That is because the helium atom is so small and there is only one atom in a molecule. Balloons are made of mylar coated with aluminum, whereas normal balloons are made of latex rubber and not coated.
Food bags are also made of aluminized mylar to prevent oxygen from getting in and spoiling the food. Vinyl lets oxygen go through, but it's so much cheaper that it is used for temporary storage. Sandwich bags are thinnest and good for a few days. Storage bags are medium and good for months. Freezer bags are thickest, good for years.
If a body displaces water equal to its weight, it floats. If less than its weight, it sinks. So the first thing you have to know is the weight involved. Let's imagine you use a kiddie pool for a boat and it has 20 square feet. A cubic foot of water weighs about 62 pounds, so if your boat carries 1240 pounds it will sink to a depth of one foot.
Thanks for the reply. I assumed the answer you gave was correct, but if sealed in the pvc pipe will it eventually escape? With Air your statement is true. Would the amount of weight it would support depend apron the amount of helium (psi) that is in the pipe? I.e. 40 psi would support more than 10 psi.
Read it again. It only depends on how much water the thing displaces. A helium balloon floats in air because the balloon with helium weighs less than the same volume of air.
I understand what you are saying, but, with enough helium the pipe would float in air just as a balloon will. How much helium does it require to make the pipe float in the air and stay there. I would guess the pipe will weigh 5 lbs. The pipe weight must be overcome first before it will support anything. Right?
You are talking as if you are not reading what I wrote. I already answered all your questions in the first response.
That assumes your kiddie pool boat has sides one foot high. If not, then it will sink.