Discussion Solar balloon free flight contest

[kevin matthews]

When I was a freshman in highschool my science teacher told us about a balloon he made and flew. It was made out of a dry cleaner suit protective clear bag that they put suits in after they are cleaned - very light weight. He made a cross out of light weight balsa, approxamately 1/8 in. square sticks or smaller. Birthday candles were put on the balsa sticks under the bag. The bag was tied to the cross with thread and proped up while large candles under the bag filled it with hot air. When it all started to lift off the birthday candles were lit and the free flight thing started to fly. It flew over the city at night as the fire light lit up the bag and made it very visible. When the birthday candles burned down the balsa caught fire and then the bag as it all burned up in mid air. If it wasn't for the fire hazard this would make a great UFO.

[busta1]

I have looked for rolls of film / plastic aswell (I'm in the UK) but can't find any here. If I do I would like to try and build one large enough to lift me a few feet. That last picture of your largest balloon is great but your right about all the taping very boring and it weighs a lot.

[mlbco]

Busta,

You're right, on the spherical balloon I built the tape was almost as heavy as the trash bags! A heat sealer that works reliably on thin plastic would be nice for building these.

Steve

[busta1]

I'm sure I read somewhere on heat sealing the bags using a soldering iron on low heat or a low watt iron, I will have a search around and see if I can find it, I think it was on a french website.

Dave

[mlbco]

Dave,

I tried that and it does work, but its tricky to do well. I had to put the bags between 2 pieces of waxed paper to make it work. If I moved the iron too slowly it would melt. Maybe there is a better technique for thin bags.

Steve

[catman529]

Originally Posted by mlbco

I'm too lazy to build a balloon big enough to lift me, but here are some pictures of the biggest balloon I built. I used 20 garbage bags and I think it was 15 feet tall. Does anyone know where to buy 0.7 mil black plastic on large rolls? That's what I need to build big balloons. Taping garbage bags together gets very boring.

Steve

looks great, I would not release it if I had made it! hope it is found sometime soon. I have built a 13-foot tetroon with 25 bags that can lift about a pound. It's a little wider and shorter than yours. You should try some AP someday and post some pics.

Seems like larger plastic supply is the discussion going on right now, so here's the best thing I have come across in all the time spent looking for larger rolls:
http://www.amazon.com/Covalence-Plas.../dp/B0009OXPYA
OK it's clear, black is not to be found, but if it didn't heat well enough, some trash bags could be taped to the inside of the balloon as solar collectors. I saw an article on a clear tetroon flying 500 miles rigged with radio gear (so it even had a good payload) and it still flew, no black at all.
One or two of these rolls could make a jumping balloon, but I want to eventually fly over our hometown in a giant solar balloon, controlled by only the sun, wind, vents, and ballast. That would be the best way to fly, in my opinion.

hope this helps, happy flying

[mlbco]

Catman,

Thanks for the link to the plastic, I just ordered some and I'll try a big tetroon to see how it goes.

Steve

[catman529]

Sweet, let me know, because I have already planned a 60x46 foot balloon that can lift a human...that would be me....so I want to do this someday, and I don't know how well the clear plastic works, so I'll be looking forward to your results.

(BTW the clear is sort of opaque, not true clear, but there have been solar balloons like this that flew long distances)

[busta1]

-great guys, I am sorry to detract from the thread but I am getting more determined to give a giant balloon a go. If you google 'solar balloon' you get a fair bit of info on how to build them (mostly from french sites). I have seen a few clear ones.

catman529 - I agree it would be the best way to fly but a few 10ft jumps would do me (I don't like heights!!!)

keep up the good work.

[catman529]

[quote=busta1]catman529 - I agree it would be the best way to fly but a few 10ft jumps would do me (I don't like heights!!!)[quote]
I will use a tigh yet lightweight plastic trash bin to hold myself and the ballast, and it will of course be reinforced with cables. I would be scared to go up in a super-thin balloon that I made myself, but the thought of flying over our neighborhood or anywhere around our area and watching peoples reactions from the air....and the view and all that....

[busta1]

-it would be awesome. Its a pity that we are at opposite ends of the 'pond' 'cause I would be interested in doing a joint build, its a big job for one person

[catman529]

Originally Posted by busta1

its a big job for one person

you're not kidding, it would take a few days maybe at least, but I would love to show off my creation and say "I made it all with no help and flew it with no help" ... of course, I would practice flying tethered to the ground, and when I got good at regulating altitude, I would let a little balloon go, see what direction it flew in, and use that to find a good launch spot (this is what they do with regular hot air balloons). We would need a good fan, not too big, but powerful enough to inflate the balloon in less than half an hour or so. Then I would be up with the camera & cell phone (who needs radios when you have a cell?) and I would fly for an hour or two, going up high for the view and photography, and spending a lot of time at low altitudes to get peoples attention...
this has been my dream for a while, and suddenly it has become more possible.

Before I invest in all this, I'm getting a Wing Dragon 4 ... yeah, in fact, I think I have enough money by now....

[mlbco]

I made a 12' tetroon from 0.4 mil clear plastic and flew it this morning. At 8:30 AM the sun was up and after inflating the balloon didn't show any tendency to lift. The skin felt cold and it didn't seem to heat well. In a fit of deparation I sprayed it with 2 cans of Rustoleum flat black and then it lifted! Here are some photos of it flying away. I wish I could find some big rolls of .4 mil black plastic because I wouldn't need paint and it is much easier to build a balllon with fewer seams.

Steve

[catman529]

wow thats awesome! The paint makes it look interesting, go and do a saucer shape....and see if you get on the news

Someday I'll find a supply of black .5 mil HDPE to make bigger balloons with, but this looks cool. Go and tape two 40-foot strips together to make a 24x40 foot sheet, then fold it in half so it is 24x20, and tape the two 20-foot sides together, then pull the centers of the open (24ft) side apart to make the tetrahedron. Once the balloon is all taped together, tape on a few big black trash bags (cut open) in random places so they hang down like banners. Then cut the mouth and invert the balloon so the trash bags hang inside the balloon, and there you should have solar collectors with no paint needed. And don't let it go, you may find it useful....

just an idea, let me know what you think

[mlbco]

I found some black plastic film on large rolls:

http://www.duboisag.com/catalog.php?...&product_id=49

I think the Horti-210 is 0.5 mil. The only problems are that the company is in France and the roll is 6 x 4000 feet! I don't have any price info.

Steve