Dumb hammock underblanket question

[VirusKiller]

Q: Why do you need an underblanket when in a hammock?
A: Because you'll get cold if you don't have one...

Seriously though, the conductivity of air is tiny compared to the the ground. Is it convection (wind) that chills the bottom of the hammock?

 

[drewdunnrespect]

yes mate you have got it in one and its annoying as hell when you wake up during the night with a cold bottom cos of no underblanket

 

[SimonM]

Simple answer - yes!

On a summers night you would be fine with a decent sleeping bag. But on a windy night, when you have compressed the insulation under you, by lying on it, you would be cold underneath.

You don't have to use an underblanket, some use a half inflated thermarest or roll mat. I tried it and didn't get on with it, so made an underblanket from an old sleeping bag. That was an improvement, but nowhere near as good as the Snugpak underblanket which I now have.

HTH?

Simon

 

[Pierr]

And maybe even more important is that a hammock compresses more of your sleeping bag. All the back and also the sides are compressed.

 

[VirusKiller]

Good stuff. I'll try my thermarest first and see how that works out.

 

[Tadpole]

I use a 6ft x3ft 10mm closed cell foam mat in my magikellyhammoch, and have had no problems with it, I do remember that I was way to warm in the sleeping bag, so now plan to use blankets with give a more flexible way of sleeping.

 

[Ogri the trog]

Yup, spot on.
Air is an excellent insulator - but if it is constantly being moved about underneath you, you'll feel the cold.
There are a few options, firstly to isolate yourself from the bottom of the hammock - foam pad. Or secondly to create still air underneath you - underblanket. But if you can hold the still air in place without any packing material, you have a Garlington Insulator - which is basically a bag of air sewn under your hammock.
There are possibly more methods of keeping warm in a hammock than you care to read about - the trick is to find a method that ticks all of the boxes that you can think of!

ATB

Ogri the trog

 

[Black Sheep]

Has anyone tried the foil cover bubble wrap type stuff used as house insulation?

It's about 6mm thick but as good as 50mm of fibreglass wool.

Richard

 

[wentworth]

Jump on hammockforums.net and browse through all the insulative materials they're trying out.
Members have been trying spaceblankets as the inner layer of an underquilt, bubblewrap, packing foam, even making visits to hopspitals to commandere medical materials for under insulation!

After trying mats, garlington insulators, underquilts, down-hammocks etc, I've come to the conclusion that a sleepingbag that encapsulates the hammock is the best way to go, like Ed Speer's Peapod, Wanderinstar's Cocoon and Ogri's Ogripod.

 

[Langers]

I have suffered badly from this now i have a SOlid fabric DD hammock. Interestingly I dont remember ever having this problem when doing army type stuff in the 90's. I used a nylon string hammock then. Maybe the string doesnt compress the insultaion as much.

Anyway using the underblanket designs on this site and others i fashioned one using a old german army surplus sleeping bag. Actually i made 2, the sleeping bag i bought was dual layer.

I would take some photos but its all in the loft at the mo.

I have used this twice now this year. And it is much better, but I will probably need to make another thicker one for my normal autumn half term getaway.

 

[VirusKiller]

Interestingly I dont remember ever having this problem when doing army type stuff in the 90's.

You're just getting older!

 

[Langers]

Yeah, thanks for that.

Like I need reminding

 

[VirusKiller]

You have my sympathy. I'd quite like a back transplant...

 

[Langers]

Here is a solution. I mentioned in an earlier post.

I must stress it was still a bit chilly at easter although fine at last half term with this setup. Its all down to the old bag you use. When I bought mine i discovered it was 2 ply. I assume to reduce cold spots where the quilting is stitched. I think I paid £12 for the old bag, which made 2 underblankets.

The seams running down the sides where already there, all I had to do was hem the edges to accept the shock cord

The other side is not as pretty. But it was cheap.

Detail of the corners, where the shock cord is exposed and attached to the hammock, and the central tightening loop.

As mentioned complete copy of what I have seen elsewhere.