when is the weather to bad to hang between 2 trees

[chrisx]

Use your Tyvek foot pad (or backup 6-mil bag) as a ground-cloth.
Some backpacks have a removable foam pad for UL-bivy usage.
Don't set up where water will collect.
Lower the tarp. Move the tarp?
Consider a rectangular/square tarp w/ ridgeline to give you more options than a catenary will. I love catenaries, but I've found them to be less versatile.
If you could rig a way to pull the hammock bug netting off you that'd be pretty nice (planning to experiment with this myself)

6 mil bag?

I quit the tyvek a couple of years back. Why? Tyvek is not water proof. I had a Tyvek ground cloth for my tent for about 3 years. In a heavy storm, with saturated ground, water soaks through, on into the tent. I switched to a sheet of plastic as a ground cloth. It is thin maybe 2 mil or 3 mil thick. The plastic came from Home Depot. It is water proof.

In a storm, I found the wind blowing a little water into the hammock with my head towards the wind. With the tarp towards the wind I stayed dry. I wraped the string on the corner of the tarp, around a large stick, and put big rocks on the stick. This held through the night. I had to have the lightest hammock. 1 pound 12 ounces. Grey foam under quilt and fabric to hold it under the hammock not included in that weight. I did not get the deluxe tarp.

What insulation can hang under the hammock for 58 nights, and also work on the ground for 2 nights, of wind and rain?

Hmm. Has anyone ever used refletix to hang under and as a ground sheet?

[Montexan]

6 mil bag?

Typically sold as contractor bags. Ridiculously tough for most uses, but I like how it lays flatter, easier.

[TheRuralRefugee]

Just Do It and never ever stop learning

I would think that an excellent philosophy for life in general.....

[sliver]

Guess I don't understand that, if you are talking about the tree trunk. Airplanes, submarines, etc., are made rounded to reduce drag...

That number is correct. Note that I said, "round" not "rounded". And, we're talking about round from the perspective of the wind hitting it. Airplanes are moving through the air with the wind flowing nearly straight down the round fuselage. However, what I'm talking about is when the wind is hitting a cylindrical object perpendicular to the long axis of that object.
wind -> || tree,
not wind ->== fuselage

If you look at airplanes, you'll see that they often use fairings around cylindrical parts like wheel struts so it present a tear-drop shaped profile to the wind, rather than round.

You're right about the "rounding", though. That reduces parasitic drag.

[sliver]

Has anyone ever used reflectix to hang under and as a ground sheet?

I don't think Reflectix is going to be nearly as durable as a 3 mil contractor bag or a sheet of plastic. You get the added benefit of insulation but it's bulky. A 6' x 29" piece of Reflectix is about 5" diameter. The foil sandwich is not abrasion resistant - it tears pretty easily.

[Sailor]

Well, it really doesn't matter...tree's probably not coming down, and as you can see, fairings around wheels, struts, etc, all approximate a symmetrical airfoil for an obvious reason. In fact, Douglas got so good designing engine cowls and cooling ducts for their DC-7, they actually were able to gen a little thrust too...

[sliver]

Where it would matter is if you're trying to decide whether it's worthwhile to pitch your camp downwind of a few trees. Once you know that they are generating more drag than you'd think, you might decide that's a good idea.