More questions for my DIY hot air balloon:
What are some very common (i.e. easy to purchase) plastic film materials that have very good flame-retardant properties?
How is the "degree of flame retarding" of a plastic film material rated, so that I can compare materials by their manufacturer's rating?
Are there any common "spray on" flame retardant treatments that could work? Or is a flame retardant plastic film the only way to go to really stop it from bursting into flames?