I am working on an idea for a light weight low cost hex tarp. So far I have been experimenting with two kinds of polyethylene (PE): High density (HDPE)and Low density (LDPE).
Obviously PE lacks the strenght of something like Cuban fiber or silnylon. To compensate for this weakness, I have been playing with a number of different tapes to provide the necessary load handling characteristics required to cope with tie out tension and the effects of wind pressure.
I have discovered a number of trade off issues that one must contend with: Tensile strength, Resiliancy, Opacity.
HDPE has greater strength to weight properties (higher tensile strength) than LDPE. Translation: you can use a lighter base material with which to construct your tarp. The downside of this material choice is that it has a lower resiliance coefficient than LDPE. This means that with less give, it has a greater suseptibility to puncture, or blow out under high load conditions. One could compensate for this short coming, in theory, by increasing the ml thickness (ex. .35ml to .7ml). Likewise, to get the strength of HDPE using LDPE one would need to use material as thick (in theory) as 2ml.
I like the idea of a see through tarp, to better comune with my surroundings in the deep dark piny woods. HDPE tends to be more opaque than LDPE. I would prefer a hex tarp constructed of light weight HDPE, but you can't see through it. So, I have decided to take the weight penalty for a better view with increased resiliancy.
Here is a link to show what I have done:http://www.youtube.com/watch?v=FgCUc_aUnb0&feature=related
Any thought or comments?