hammock Underblanket Alternative

[wistuart]

I think that the guys at www.hammockforums.net have thought about it, (maybe) tried it and dismissed it.

I haven't tried it, but this springs to mind:
- Thin, prone to rip material, with your weight on top = 1 little hole can become a big rip?
- That same material seems difficult to attach to straps or something to connect it to the hammock.
- To insulate, it must keep air trapped underneath you. Therefore, there must be a little bit of room between hammock and blanket. With thin, floppy material that will be difficult.
- A good gush of wind and any air trapped in the "in between" will be blown or pushed out.
- Think about the wrinkly sounds this material makes. My brother spent a night in one of these. He slept great, but every time he turned around in his sleep he woke everyone up with the aluminium-foil-sounds. Imagine it's a bit windy or you turn over in your hammock....


I think there has been talk about using an emergency blanket here or on Hammockforums, but the a thicker kind like this below:

Though I think it won't hold much air, it might be worth a try.

I believe you are thinking of a traditional single layer foil emergency sheet. The blizzard blanket I'm referring to is different. It uses a multi layer construction so the insulating air is actually trapped inside it. It's also reputed to be a fairly strong material and of a robust construction. Have a read through the site I linked to in my original post for a better description.

 

[mjk123]

>>I have made a few insulated hammocks

Wentworth,
Have you got any pictures of these?

cheers

 

[Glen]

I would think that a mat like Exped, which has channels in it would help reduce the sweat issue.
Hennessy uses open cell foam in their undercover. This would allow sweat to escape too.

Exped make ( or at least made, as I haven't checked they still do ) a Hammat http://www.produkte24.com/cy/exped-ag-815/exped-matten-und-biwaksaecke-874/seite-11-gross.html
Never tried one and never even found anywhere that sold them in the UK, seemed to be mainly the Swiss market judging by the few online stores I did see them in 2 years ago.

 

[wentworth]

>>I have made a few insulated hammocks

Wentworth,
Have you got any pictures of these?

cheers

Yep, there's a couple of photos in my gallery. The blue one has a heavier material for the hammock. But it also had a very small insulated area. If you didn't lie in exactly the right spot in the hammock, you'd be cold.
So I made the brown one, lighter hammock material, much larger insulated area. It's almost perfect.

I'd love to put together an article comparing all the hammocking ways to keep warm, as I've tried JRB underquilts, Speer Underquilt, 4 insulated hammocks, Double layer hammocks, CCF foam mats, thermarests in hammocks and sleepingbag around hammock. All have their good points.

 

[harryhaller]

Yep, there's a couple of photos in my gallery.

Where's your gallery?

I found the DD hammock, with a sleeping mat stuck underneath in the compartment, warm enough at temps hovering around zero - in fact I completely forgot my underside - it was no issue.

I've ordered the coccoon in the group buys hoping that that will get rid of the dilemna of what I should use to cover the hammock (I don't like sleeping bags, though I can tolerate them if they have plenty of room)

 

[wentworth]

http://www.bushcraftuk.com/index.php/Gallery.html

Go to "W" for Wentworth, I'm on the second page.

 

[harryhaller]

Aah! I've never knew this gallery existed.

How does one enlarge the photos? Sorry - I've tried everything I know so far.

 

[wentworth]

Oncde you're in the gallery you just click on the images and they enlarge, or they do on my computer. Are they appearing small on yours? No idea!

 

[harryhaller]

Nothings happening on my browser (firefox) - OK, I'll try another browser.

Na, it's the same with Opera - some photos work, some dont.

It's another bit of software made according to the motto - why make things simple when we can make them complicated.

 

[mjk123]

Wentworth,

I get the photos small too. So I just sit closer to the screen. Anyway, quick question: Have you just sewn a kind of mega patch to the underside of the hammock by only sewing around the perimeter, or is there some stitching anywhere in the middle of the down "pad"? And how did you judge the depth of the pad so that a) the pad doesn't just flop down leaving an air gapp, and b) the weight in the hammock doean't either compress the down or rip the stitching?

And just one more. Have you ever found that sewing the hammock weakens it it any way?

Thanks for your time.

 

[wentworth]

It's a big rectangle of 1.1oz nylon. After hemming it, I sewed 3 lots of 1 inch darts on each side. I then sewed the rectangle to the bottom of the hammock, leaving a gap so I could put the down in. The darts make the pocket billow out from the hammock, so the insulation doesn't get compressed.
I then put either 4 or 6 oz of 900 loft down from Ed Speer into the pocket and sewed it shut. No need to add baffles or anything to keep the down in place. Once in the hammock, I spread the down to all four corners with my hand, and it's stayed in place pretty much ever since
I've never needed to, but if you were ever too warm, you could push the majority of the down to one side of the pocket, leaving you with less insulation underneath you.

http://www.hammockforums.net/gallery/showimage.php?i=669&catid=4

With the 4th hammock, I used 1.9 oz for the hammock body. I have found that the stitching of the pocket has slightly weakened the hammock. I wasn't a problem with heavier body material though.
If there was a way to glue it, without the glue decaying the nylon, it would be good. But the hammock body does stretch when you get in and through constant use, so the glue would have to be able to accommodate that.
I used zigzag stitch, as this has more stretch to it.

And just for good measure, an insulated hat I made for winter hammocking...
http://www.hammockforums.net/gallery/showimage.php?i=793&catid=member&imageuser=65

 

[harryhaller]

Great photos - I can see them

I find a good solution for the cold is in addition to a double bottom with mat, to have whatever you are covering yourself with, hanging over the sides and tied up under the hammock.

For example, poncho liners.

Taking it further, for very cold conditions, an extra ridgeline under the tarp from which to hang a blanket, opened up sleeping bag etc to trap the heat and to be an extra buffer for the descending cold air.

But the problem with all this is the weight - ok if you're travelling with a car, but not realistic if you're hiking.

However the principle of having something hanging over the sides of the hammock is sound - it stops wind before it even reaches the underside and keeps any radiating heat from being blown away. I mean this as an additional measure to the double layer.

I've just had a bad night with an icy breeze and the main problem was "above" not "below". The mat in the double layer is quite effective.

 

[harryhaller]

Second thoughts - I'm going to do an experiment:

I have two DD hammocks, one the famous travel hammock (with mozi) and the other the scout. I will rig the the scout up so that it lies on top of the travel and is attached via 3mm elastic shockcords to the travel at each end.

The bottom part, the traveller will have a sleeping mat in its pouch, which seems to do the job. The upper part, the scout, will have a wool blanket inside its pouch. The scout is slightly narrower and short than the traveller. I will then have a cocoon type arrangement, hopefully fixing the problem of the cold top, which from my experience is now the greater problem at sub-zero temps.

Tonight it will not be freezing according to the forecast, but tomorrow night it will be minus zero, so I'll have two good chances to test it.

I might also try it the other way around - scout underneath and travel on top.

I will still use pocho-liner and blanket inside, of course.

 

[Ogri the trog]

I had some free time yesterday and tried some different configurations for spring-time hammocking.
My Ogri-pod is way too bulky to be anything other than a testbed and an ongoing project so I need a rethink to get things to a manageble size.
Step forward the lined poncho idea - Uk poncho is just plain ugly as rain wear and bulky in its own right as a hammock item. US item I have (probably a knock off) is too narrow. Hmmm how about a Webtex Tarp, seems to fit the bill, but only just. It works well as a wind resisting layer, but needed something inside to maintain the all-important air gap. I tried clipping a blanket to the inside with questionable success; it didn't leave much blanket to wrap over the top of me once inside. My idea was to create a "Figure Six" where the insulation clips to the windproof layer on one side, goes underneath and has enough spare to become the over blanket, forming a big "6" around you. My problem is that I'm too big around for it to work without having a blanket that meaasures ten feet square!- negating any low-bulk, light-weight ideas.
Then I tried various options of putting a wool blanket inside the hammock and this is where I'll have to have a bit more testing time. With the blanket arranged diagonally along the hammock length, there is enough to wrap over the top and keep feet and head warm and it isn't that huge to carry around (not light by any means but portable enough to start with).
I have tried sleeping on a CCF mat inside the hammock (its a group buy one, single layer) and I do get a little sweaty but its not too bad.
I think my next test session will be a CCF pad and a wool blanket, just to see how it pans out.

With no job at the moment, everything looks expensive!

ATB

Ogri the trog

 

[harryhaller]

I think I'm moving upto the point from which you are now trying to move away from, Ogri.

I've put some velco strips in the scout hammock so that it's like the travel hammock so that what's inside the pouch doesn't fall out. I've put three synthetic quilts which I picked up from the charity shop inside. The scout I tie down at the foot end, real tight and cosy, with the elastic shockcord attached below the level of the travel hammock's point of attachment. So that's the feet snug. I tie down the head also below the level of the travel hammock's point of attachment with elastic shockcord. Because the scout is shorter than the travel, the scout comes up to where my chin will be.

So effectively the scout is now a quilt which one can tie down at each end and which pushes down on the travel hammock, the edges of the scout hanging over the edge of the travel hammock. Got in - and yes it is very snug and warm.

Problems? Well the contents are going to shift - the quilts aren't exactly the size of the pouch - but since the scout is fixed and one can move underneath the scout hammock without moving it, it should not be too bad once the the quilts are laid out correctly. I will get some more velco and see about the possibilty of strapping down the quilts so that they don't move within the pouch.

The other problem - and the reason for my opening remark - is that those quilts nearly filled up the rucksack when I brought them home from the charity shop - they're not heavy, but bulky.

But the principal works ok - "all" I need to find is some low bulk insulation material to replace the quilts - and I bet that is going to be the expensive part.

 

[wentworth]

I'm trying to envision your invention. The quilts are inside the hammock? or inside the pouch? Anything other than on the outside of the hammock will compress the loft.

As for buying insulation to replace it, if you go to a material/ sewing shop, you should find polyester batting. It's not quite as good as primaloft or polarguard synthetic insulation, but it is light, cheap and warm. Here in Australia it's round $5 a meter. You can either use it to make an insulated hammock or an underquilt. Should be able to find some ripstop nylon for the outside too.

Look forward to seeing what you end up with!

 

[Ogri the trog]

Batting is on the cards, when I can afford it.
Another idea is to take a feather down duvet, split the inner baffles, squeeze the insulation towards the middle, then trim the outline to become an under blanket profile and add the supporting network of cords.
Another is to try some of the foil based building insulation. Tape, sew or glue it into a boat hull shape and use that as an underblanket.
To address the bulk, I tried those vaccuum bags for bedding storage, they worked OK but the seams weren't up to the task of taking the abuse of being packed into a bergen more than a few times. Whatever I end up with as a long term solution will have to bear being rolled or stuffed repeatedly into a stuff sack or similar.
On hammock forums, there is a movement that advocates wearing thermal suits and fleece layers, but I think this is taking things too far to actually enjoy your time in the wilds.

It's all pie in the sky for now as I have many other things that need financial commitment before playing with new hammock ideas.

ATB

Ogri the trog

 

[harryhaller]

I'm trying to envision your invention. The quilts are inside the hammock? or inside the pouch? Anything other than on the outside of the hammock will compress the loft.

Sorry, I should be more precise. There are two hammocks: the DD travel hammock, which is the one you are going to be lying in, with a mat or pads as insulation for underneath, and the second hammock, the DD scout hammock, which is going to cover you and keep you warm from above. It has the quilts in its pouch, which isn't compressed since it is the hammock which is covering you - not the one you are lying in.

The point of view I am starting from is that the bottom insulation is no longer a problem - the problem is keeping warm above.

As for buying insulation to replace it, if you go to a material/ sewing shop, you should find polyester batting. It's not quite as good as primaloft or polarguard synthetic insulation, but it is light, cheap and warm. Here in Australia it's round $5 a meter. You can either use it to make an insulated hammock or an underquilt. Should be able to find some ripstop nylon for the outside too.

Thanks! I'll look into that - that was the next problem to solve - replacing the thre quilts in the top hammock with something more manageable and less bulky.

Look forward to seeing what you end up with!

Oh dear! That's the next expense I fear, buying a digital camera

But it's finished virtually - at least functionally - thanks to your tip it will soon be completely finished.

 

[harryhaller]

On hammock forums, there is a movement that advocates wearing thermal suits and fleece layers, but I think this is taking things too far to actually enjoy your time in the wilds.

That isn't such a bad idea, I think, and it fullfills the aim of of dual functionality - as opposed to carrying a large bulk which only serves one purpose. Thermal suits and fleece layers also have their place in daytime activities - when the weather closes in. I think keeping warm helps enjoying our time in the wild - I certainly didn't feel very merry last night frozen to the bone!

It's all pie in the sky for now as I have many other things that need financial commitment before playing with new hammock ideas.

Check out car boot sales, charity shops etc - it's amazing what one can pick up - I'm a real urban forager

 

[mjk123]

>>The point of view I am starting from is that the bottom insulation is no longer a problem - the problem is keeping warm above.

I'd almost reached the opposite conclusion. A hammock is worse than lying on a concrete floor. At least on the floor you're resting on your hips and shoulders; the bits in between aren't as compressed (just). Maybe 20% of your body surface is compressed. In a hammock, the material squeezes you from below and the sides and conforms to your shape so that you're squeezed along your whole body length. Probably 50% of your body is in contact with the hammock. Any clothes you're wearing, unless they're made of stiff foam, will be compressed.

Try the following; put on a pair of jeans and lightly scratch your leg with your finger nail. You'll hardly feel it. Then lie in the hammock and scratch through the hammock on your leg. You can feel it much more. I'm even convnced that a hammock compresses the fat layer under your skin thus reducing insulation. great on a summers day. Not so good on a spring night.

But this thread is encouraging me to get the needle and thread out. Many thanks for that.