Hot air balloons made of what?

[AWACoff]

Alright all you wiseguys...I know, I know...
What I'm really after is what type of material are the envelopes of typical hot air balloons made of? Why do they not show up very well (if at all) on local ATC radar? If I bent over and mooned the antenna site, would my heinously white bum cause a large primary target if I were the pilot of said balloon? Thanks.

 

[ShawnC]

Ummm hot air?


I really don't think that the human flesh would bounce that many radar waves. I think that huge torch would would emit more radiation.

 

[Goffer]

For some reason nylon comes to mind.
Does porous material effect radar returns?

 

[jsoceanlord]

I've got 150 hours in 'big' 6 passenger balloons.

a training requirement was to go to 5000 feet, which i did not far from the approach to march AFB, near L. A. Kinda weird looking down at KC-10's.

I don't remember if we were talking on the handheld or required to. best thing is we're easy to see and avoid.

the burners are about the only metal. we'd only fly when winds are calm at sunrise or maybe sunset. this was about twelve years ago, before the airspace got more controlled than uncontrolled.

 

[boscenter]

i know Mylar & Tedlar are used to produce blimp/airship envelopes... no idea if the same is true for balloons...