How long does helium balloons stay afloat?

[southernleftylady]

baby will's bday party starts at 4...
when should i do the heliums?
tia
(typing with baby on lap...)

[ScreamingMeemie]

1. Hi Baby! Have a great party!! Are they latex?

I would blow them up at 1 ish. :hi:

[southernleftylady]

2. no they are the metalic ones

[ScreamingMeemie]

3. Mylar ballones will last for at least a day in warm temperatures, up to

a week in colder temps. I'd blow them up now then if you have the time. :)

[southernleftylady]

5. thank you so much :) this party will be too cute .. cant wait to post ..

pictures of it ;)
yall know how much i love posting pics ;)

[ScreamingMeemie]

6. I can't wait to see them!

here at DU, you have a captive audience! :hi: Have fun!!!

[Frank Cannon]

4. The mylar/metallic ones will stay up for a long time

I had one a long time ago that kept its helium for nearly a month!

You should be okay any time today you want to inflate them.

[NNadir]

7. Several days in my experience.

[Orsino]

8. The helium escapes through the plastic...

...because it's a monatomic gas--the smallest possible molecule is the single helium atom, which does not chemically bond, even with itself. Plastic is full of spaces though which the gas can escape.

In my experience, ballons won't visibly droop for 2-3 days, and will remain buoyant for a week or more.

[doc03]

9. I once found one in the woods while hunting that had come

from over 200 miles away. It was released from a proposed hazardous waste site by an environmental group to illustrate how far the pollution would travel, so I would say several days.

[EstimatedProphet]

10. For all practical purposes, forever

The only reason they start to fall is because the helium leaks out. Get a really good seal and it will stay a really long time.