hammock Underblanket Alternative

[wistuart]

Hi

I'm going to be buying myself a hammock in the very near future and am considering the various options for an underblanket. One possibility that I don't think I've seen discussed is to use something like the small Blizzard Survival Blanket (http://www.blizzardsurvival.com/product.php/111/blizzard-survival-blanket-small). The pack size, price and weight are major pluses for me if it would work, but it's the "if it would work" bit I'm not 100% sure about. I'm confident about the general effectiveness of the Blizzard system going by their endorsements, just not sure about applying the material to the role of hammock underblanket.

Thoughts or experiences anyone?

[j.dee69]

Hi, how do you intend to use it laying on top of it or attaching it to the underside of the hammock? if attaching to underside will you leave an air gap? as an hanger myself i'd love for this to work somehow. i've heard from nick at dd hammocks he use's a silver car windscreen cover. i've got a snugpak underblanket but it takes up too much space in the bag. please keep us informed how you get on.

[wistuart]

I was thinking that hanging underneath was the most sensible option. The material Blizzard uses is compressable so lying directly on it would seriously compromise its insulating properties in the same way that down or fibre would suffer.

I haven't completely ruled out the Snugpack underblanket but it is fairly bulky, heavy and expensive by my standards.

[j.dee69]

Dragons den idea? i wish snugpak or other sleeping bag company's would make a bag that has a system to pull the hammock though the bottom end of the sleeping bag and then clip's to the bottom end of hammock, so you have the sleeping bag above you as normal but them goes under the hammock instead of under your body. what do you think. good idea or bad?

[woof]

Sounds like the sort of thing you could use a cheap sleeping bag to make, as they seem to be the folded duvet type, and you wouldnt lose much if it does'nt work.

I'm still on the fence as regards hammocks. As anyone tried the 10th wonder hammock ?.

[chas brookes]

:D Hi
if you follow link below you will find the item you are after some one has done a lot of hard work on this one and beaten you to it :)

http://www.bushcraftuk.com/forum/showthread.php?t=30046

[w00dsmoke]

For under a tenner ;-)

http://www.bushcraftuk.com/forum/showthread.php?t=37321&referrerid=5493

[j.dee69]

Bugger and i thought i'd make million's from it. oh well back to the day job he he.

[j.dee69]

Never heard of the 10th wonder do you have a link for it please.

[woof]

Just tap in hammock on ebay, there is loads, and they are cheap.

[mjk123]

I think the coccoon idea is far from ideal. The problem with the hammock is that when you're in it the sides of the hammock are taught (like two slackish ridgelines), but obviously your weight keeps the bottom of the hammock down, a bit like an upside down Sydney harbour bridge. Any attempt to enclose the hammock has to allow for this, thus the coccoon is quite large, and long. Different people prefer their hammock at different tensions, of course, which doesn't help manufacturers produce a uniformly suitable product.

Another problem is that a hammock is basically a piece of rectangular material gathered up at opposite ends. When loaded, in the middle the material stretches around the occupier, and at the ends the material bunches up. This makes it difficult to attach insulation directly to the hammock without having the stitching come under enourmous stresses as you move about, or having the bunches simply compress the insulation thus reducing it's effect.

My ideal solution (imaginatively) would be to get someone of equal size and tension preference to lie in the hammock, then paint glue onto the underside of the hammock, then stick wool to the glue. In this way the insulation can be added where needed, it would self adjust as you move about, and there's no cafuffle with trying to attach an underblanket/coccoon without dragging it on the floor or getting the elastic wrapped around twigs. The isulation is never compressed, conforms to your body, and there's no air gap.

My less than ideal but better realisable solution is to sew an underblanket to the hammock in the middle third only, allowing the end thirds to be held by elastics to the hammock rings. This isn't much different to a standard underblanket setup except that by attaching directly to the hammock at several points I'm not relying on streching the longtudinal shock cords too much and I hope to avoid 15 minutes underblanket "tuning" before bedtime

This gives insulation from below only. The next step is either to use a quilt, or even sew a quilt to the inside of the hammock.

For stealth camping, the hammock beats any tent, and up to now I've been warm enough with the group buy underblanket plus quilt. But I'd like if possible to reduce weight and bulk and to cut down the time it takes to make and break camp.

I'm glad someone started this thread; I'm sure that collectively we''ll get some great ideas.

[alpha_centaur]

This might be a really silly question but could somebody not just make an insulated hammock? Rather than an attachment for adding onto your current one

[Carbuncle]

This might be a really silly question but could somebody not just make an insulated hammock? Rather than an attachment for adding onto your current one

Et voila!
http://www.tothewoods.net/HomemadeGearDownHammock2.html

Looks a nice idea, but not very flexible (weather wise) and won't save much in terms of bulk/weight. On the main subject of the thread, I'd be interested to see how it (the foil thingy) works, but I'm a touch cynical, given that the requirements aren't that disimilar than for a sleeping bag, and you don't see too many people using them for that! The underquilt/top quilt is a touch on the bulky side, but when you bear in mind that it replaces a thermarest and sleeping bag it's pretty good, and it works (very well, too).

I've got a coccoon on order from the group buy though, and I'm really excited by it. I've really fancied one of the speer peapods for ages, but they cost a fortune. The execution of the coccoon seems a little different (I'm planning on running some shockcord inside, between my carabiners at each end of the hammock, and open the zip up at the side) but everyone seems enthusiastic. In anything other than midgey hell it should be superb.

[j.dee69]

This might be a really silly question but could somebody not just make an insulated hammock? Rather than an attachment for adding onto your current one

That not a bad idea but in the summer months you will still be carrying all that extra weight when you don't need the insulation

[Thijzzz]

Blizzard Survival Blanket

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. :rolleyes: 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:

http://images.mec.ca/media/Images/Products/HealthSafety/0199141_v1_m56577569830482184. jpg

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

[wentworth]

I have made a few insulated hammocks. The hammock, plus down insulation and suspension weighs in around 600grams. Insulation runs from my head down to my knees. My design was a cross between JustJeff's and Risk's.
Even in warm weather, you always need some insulation underneath. Well, unless you're in the jungle perhaps. In summer, I've slept in just the insulated hammock with no top cover. My heat goes into the down and is then radiated back up, keeping the rest of me warm.

If you google "Garlington insulator", you'll find that suspending a waterproof piece of nylon under the hammock, then putting semi inflated garbage bags and space blankets has been tried. One problem with waterproof or non breathable materials under you is that you will wake up in a puddle of your own sweat.

Someone mentioned all the different bumps and curves that occur on the underside of a hammock. A regular underquilt can't really compensate for this, but Ed Speer's Snugfit has around 30 darts strategically sewn into it to match the sleeper. Very expensive, but it is the only quilt I've tried that does not compress.

The Speer Peapod needs a top quilt inside to fill the dead airspace. Apparently the Cocoon has been used by itself, so let's hope it can be used stand alone!

[jabbadahut]

I am literally, any day going to buy myself a hammock and the insulation was a concern of mine, i thought the DD hammock with its double layer to put a foam mat or quilt into would take care of the keeping warm in the middle of the night scenario.
is the double layer idea not efficent? what would be best to use between the layers? foam mat, inflateable mat or quilt......?
glad i read this as i dont want to waste money. i hate waking up cold

[Hammock_man]

The use of a mat in the double bottom of a DD works very well indeed. Its when the temp really begins to drop that folk look for an extra layer.

Would you camp in a tent with just a CCF mat in winter? Its not enough for me, which is why folf look for that bit extra. Also a tent can get rid of a lot of wind chill, a tarp may not be so good. Come back to that extra layer to the hammock "Skin"

[jabbadahut]

Thanks, thats put my mind to rest, looks like i will be ordering my hammock after all,

[wentworth]

I find that even when using a closed cell foam mat in a double layer hammock, I still wake up with sweat underneath. Others seem not to have a problem. It has to be either two mats side by side or an extra wide mat so your shoulders don't get cold.
The nice thing about the double layer is that it keeps the mat in place, in a single layer it will be sliding out from under you.
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.

[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. :rolleyes: 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:

http://images.mec.ca/media/Images/Products/HealthSafety/0199141_v1_m56577569830482184. jpg

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!:confused:

[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.

[Hammock_man]

I have slept on a concreate floor
I have slept in a hammock

I know which one I will repeat from choice

[traderran]

Pic,s work fine for me.

[soa_uk]

I use underblankets with our hammocks.

I've used nothing, and froze. I've used thermarest, both under and in the bag, and fell off them.
I've used windscreen covers, and slid under them in the bag... and if you have them below the bag you'll think you have other problems(see http://www.bushcraftuk.com/forum/showthread.php?t=10754).

How do I cope with the bulk of the underblankets? Bought a bigger ruck.