PDA

View Full Version : Under Hammock Insulation



Steinberger
2005-08-18, 23:17
I before have never used my hammock in weather below 25F it just doesn't get very cold here in North Carolina. I am planning on doing some hiking up in Vermont, New Hampshire, and hopefully inontario and British Columbia so as you can imagine it will be much colder and just my sleeping bag won't cut it even though I am pretty warm natured. I would love to get a Super shelter or JRB underquilt and weather sheild but I am just too poor. What I am thinking is to make something like a travel pod except that would fit the Ultralite Backpacker A-sym. I am wondering if anybody could help me with sizing or the right materials and where to get it. I am guessing Silnylon or would something else be better? Any help would be greatly appreciated. Thanks

GregH
2005-08-18, 23:51
You could literally use blankets, a tarp, and some bungee cords and rig a system that would get the job done for very little money. It may not look pretty but it would work and you could assemble it from items you probably have around the house. It might be a bit heavy but you did say you're strapped for funds.

Just Jeff
2005-08-19, 00:20
Several undercover options here:

http://www.geocities.com/jwj32542/HammockCampingWarm.html

txulrich
2005-08-19, 09:58
JRB makes a Weather Shield, http://216.83.168.206/index_files/Weather%20Shield-v2.htm that will fit on the hammock. You could then line it with whatever insulation was appropriate.

Just Jeff
2005-08-19, 11:31
Ray Garlington just puts a bag of down inside a silnylon undercover...no baffles or anything...and says it keeps him warm. Maybe you could buy a weathershield, then just get a bag of down to put inside it. Sewing a bag of down would be very easy.

txulrich
2005-08-19, 12:05
Ray Garlington just puts a bag of down inside a silnylon undercover...no baffles or anything...and says it keep him warm. Maybe you could buy a weathershield, then just get a bag of down to put inside it. Sewing a bag of down would be very easy.

The baffles only serve to keep the down in place and prevent cold spots. This would prolly work ok as long as it didn't get real cold.

Just Jeff
2005-08-19, 14:14
I think he's been below freezing in it.

txulrich
2005-08-19, 15:59
I would think that it would be a matter of making sure the down was evenly spaced to minimze the risk of cold spots.

Just Jeff
2005-08-19, 18:17
Agreed.

I've considered trying the Bag 'o Feathers just to see how I like it. I'm sure it would stuff smaller than the JRB, just not sure I'd stay warm around the shoulders.

Right now all of my down is in my Down Hammock. I think that might not work so well over time, though...I sleep directly on the baffle seams, so over time those seams might fail. That would just make it like a Hammock o' Feathers, though. But I don't think I'm gonna drop the money on more down until I make up my mind about the Down Hammock.
http://www.geocities.com/jwj32542/HomemadeGearDownHammock.html

Steinberger
2005-08-19, 19:42
I have been thinking on this subject a lot lately. Thanks to you guys re-discovered the Clark North American and thought about how to implicate some of it's design features to the HH. Mainly one of the ideas which is to add sealable pockets to the critical areas under the hammock. How do you guys think the hammock would hold to the extra weight distrubuted like that, would it throw off the hammock's opening function, stabilty, or comfort in any way? It would be great because I can sometimes Have a lot of gear when I go backcountry snowboarding with my freinds up in Maine and BC and it would be nice to be able to not only keep them closeby and waterproof in some of the big snowfalls but, also use them for extra insulation. I imagine that adding weight to the bottom would just make the port on thebottom stay closed all the time right?

What I am looking for is something that would be able to cover the whole length of the bottom preferably to make it waterproof. Storage would be a nice benefit. Weight isn't really the problem but bulk is because like I said earlier I can have a lot of gear when My and my freinds go snowboarding in the backcountry and I would like to eventually be able to my hammock isntead of us all staying in tent burried under four feet of snow of drifting snow and then having it melt form the heat of the ten and leak in at the zipper.

I am going to see if I can draw some of my ideas and maybe post them on here later on to see what you guys think of the plausiblity of it is. Good job if you are reading this you most likely managed to make it to the end of this message. Now am I forgetting anything?:hmmmm:

Steinberger
2005-08-19, 21:51
Here is a very vague concept I am going after. Warning: the drawing is pretty quick and bad..

http://www.alcarter.net/images/Hammockinsul~1.jpg

Does anyone see any possible problems with this?

Another idea is to attach the pocket baffles to the hammock so they cand be used year round what do you think?

Just Jeff
2005-08-20, 00:56
That might work. You might consider shock cord or elastic instead of webbing straps because the hammock fabric will stretch but the webbing won't. This can cause the hammock's edges to turn down when you load it.

One thing to remember - any air pockets between the undercover and hammock will cause a cold spot in the hammock. Putting gear in the undercover can cause cold spots if it's not pulled tight against the hammock. Moving an elastic strap (or adding an extra) to where the gear will be stowed would help.

Also depends on what you use for the "durable padded bottom." If it's a closed-cell-foam pad, you'll have a hard time shaping it to fit the hammock. It will buckle and cause airpockets. You can cut and shape it with some trial and error...pads are pretty cheap if you want to experiment.

If you don't want an undercover or weathershield-type covering, maybe you could get a SPE and a pad, and then sew some small pockets to the inside of the HH for storage.

Keep us posted on your experiments!

Steinberger
2005-08-20, 18:01
One thing to remember - any air pockets between the undercover and hammock will cause a cold spot in the hammock. Putting gear in the undercover can cause cold spots if it's not pulled tight against the hammock. Moving an elastic strap (or adding an extra) to where the gear will be stowed would help.

Are you sure about this. Let me clarify that the air will not be able to circulate under the hammock. I know they have used dead air space as the only insulation in older houses for years and it worked pretty well. Anybody have any other information on this?


Also depends on what you use for the "durable padded bottom." If it's a closed-cell-foam pad, you'll have a hard time shaping it to fit the hammock. It will buckle and cause airpockets. You can cut and shape it with some trial and error...pads are pretty cheap if you want to experiment.

By padded I just meant a thick durable patch of fabric of the bottom of the undercover under the pocket area with a little cotton batting behind it to help prevent tears and abrasion from the gear in the pockets. Not really for insulative purposes but it wouldn't hurt it either.


If you don't want an undercover or weathershield-type covering, maybe you could get a SPE and a pad, and then sew some small pockets to the inside of the HH for storage.

But, I do want an undercover. Some areas I would want to try to take the hh to and never have been able to before would require a waterproof undercover or you would get absoluteyly soaked form snow aginst the battom of the hammock melting and getting absorbed. I just though it would be useful to have the pockets because I have a Big pack compared to any ultralight hiker. I use an Osprey Ceres 70 which is about 4200ci. and I would like to be able to sotre it with me but I don' think I could fit the pack and myself in the hammock together.


Keep us posted on your experiments!

Will do.

Just Jeff
2005-08-20, 18:26
Are you sure about this. Let me clarify that the air will not be able to circulate under the hammock.

Any gap between the insulation and the hammock will cause a cold spot there. The undercover will create dead air space, which will keep the air currents to a minimum, thereby reducing convective heat loss. However, your body will still be required to heat that air pocket or the pocket will return to the ambient temperature. Since that air pocket is less efficient at retaining the heat than insulation, your body will feel it as a cold spot because it's sucking your heat away.


By padded I just meant a thick durable patch of fabric of the bottom of the undercover under the pocket area with a little cotton batting behind it to help prevent tears and abrasion from the gear in the pockets. Not really for insulative purposes but it wouldn't hurt it either.

Ah...your gear will go inside the cover between the insulation and the hammock? I thought the pad would go against the hammock and the gear would go on the ends, between the pad and the end of the cover.

I wouldn't use cotton...it sucks water like a sponge and is useless as an insulator when wet. Synthetic insulation might work better and be lighter (though a little more expensive).

But if you'll have space between the batting and the hammock, insulation won't make much difference for warmth.


But, I do want an undercover. Some areas I would want to try to take the hh to and never have been able to before would require a waterproof undercover or you would get absoluteyly soaked form snow aginst the battom of the hammock melting and getting absorbed. I just though it would be useful to have the pockets because I have a Big pack compared to any ultralight hiker. I use an Osprey Ceres 70 which is about 4200ci. and I would like to be able to sotre it with me but I don' think I could fit the pack and myself in the hammock together.

I was talking about a JRB Weathershield or Garlington Taco type undercover...they're not really designed to hold much weight like your design will.

Have you seen Youngblood's and Chet's tarptent setups? You might be able to adapt that...just put an undercover on your hammock for warmth, and with the tarptent you can just hang your pack from the hammock support and it'll be safe from the snow.

Or use the tarpent with a gear hammock. Pretty light and very versatile. My design is here: http://www.geocities.com/jwj32542/HomemadeGearPackCoverGearHammock.html and JRB's production model is here: http://www.jacksrbetter.com/index_files/Jeffs%20Gear%20Hammock-Pack%20Cover.htm

Steinberger
2005-08-21, 22:03
That gear hammock looks like a good idea. I need a new pack cover anyway and if I could still get the original color it would match my pack! :biggrin:

I have a question about it though. Does it attach to the ridge line it looks like it does in the picture and I thought it couldn't hold much weight.

peter_pan
2005-08-21, 23:24
Steinberger, et al,

Here are a few ways to hang and use the Gear Hammock...Rig a separate line or attach it directly to a HH...Gear Hammock Pictures ( http://www.jacksrbetter.com/index_files/Jeffs%20Gear%20Hammock-Pack%20Cover.htm)

Pan

Just Jeff
2005-08-22, 00:05
I wouldn't attach it to the tarp's ridgeline if you put anything heavy in it...you can run a separate line, though.

The easiest thing is to put it on the hammock support line and the A-sym tie-out at the foot end. You don't need any extra line for that, but it's a little bit vulnerable to wind-blown rain depending on which tarp you use (definitely vulnerable if you use the stock BP UL A-sym tarp).

You can also run a separate line and have it hang right beside the hammock. Or you can just clip all 4 corners to the hammock support and use it like a stuff sack at the foot. Or just put your stuff in and set it below the hammock. Or leave your stuff in your pack and use it as a pack cover...clip the pack to the hammock support or set it on the ground.

It's a very versatile piece of gear...but I may have a little bias there :p

Steinberger
2005-08-22, 00:27
No I have to agree with you, that gear hammock is a great idea and is so simple too. You all have been very helpful. I think I have decided to go with the canoe blue underquilt with the Jeff's gear hammock made by JRB.