Model Balloons

Does anyone have any info or plans for model balloons?

http://www.modelballoon.com/

If you're willing to clear off a kitchen table & spend an afternoon, this site has plans for balloons made from garbage bags & tape: www.solar-balloons.com

I got hooked & started building with painter's plastic, it's easy to find the really thin film at Lowes or Home Depot, though they don't have the thin stuff in black to let the sun heat it up for free. See my $5 garbage bag of the skies fly at http://www.youtube.com/watch?v=mTaL0Q6FzfM& feature=channel_page
Description in (more info) at: http://www.youtube.com/watch?v=rW8n3OiqqRE& feature=channel_page

aerostatMilpitas, welcome to the forum That's great! How long did it hold up for (I couldn't make out from the clip)

The balloon in these clips flys around 2 to 5 minutes before cooling and comming back down. Wind's the biggest factor, then fuel temperature(!) The propane tank cools enough to gather frost on the 2nd or 3rd hop, and it doesn't put out as much heat. It'd free fly higher & longer, but there's way to much traffic here to risk it comming down on someone's windshield, I've got to tether it.

Right, aerostatMilpitas Way to go for your precautions about the traffic and the danger it can cause. Kudos.

What can be done to keep it in the sky for longer without drifting off to where the traffic is?

For duration I'd love to return to North Dakota where there are miles of snow-covered wheat fields and send the fire up with the balloon. Alas, that wish won't pay the ticket, so I'm back to:
1. Find still calmer air, not very satisfying
2. Lighten the load, leave the camera off, though inverts get more likely
3. Heat it up hotter, though a weed-burning torch is too boisterous for a city park
4. Build a bigger envelope. Volume increases faster than surface area, maybe I can cut & tape out on the driveway instead of the kitchen table.

I'm actually finding more possibilites by going smaller. Little 3' tetroons inflate in 4 seconds, and warm up in 10 with a simple hair dryer. They'll fly for 30 seconds with half a pencil to keep them upright, and I can build one in less than 30 minutes. Much closer to the attention span of grade schoolers.

We must brainstorm together one time - there's gotta be a way to keep those balloon up in the air for longer...