Bag Liners

[Kraken Skullz]

Anyone making bag liners? If so, what material is easiest to work with and which do you find is the most weigh and warmth efficient?

[Meriadoc]

I'm interested in this too. I used a synthetic one that was designed to add 10 degrees F but that simply weighed far too much for how much warmth it added (less than advertised). I have also tried to use the emergency bivy from SOL as a vapor barrier.

I tend to think a tightly woven nylon (wind resistant) would work but it might not be that comfortable.

Following this topic!

[grayfox]

I just survived the video game so I guess I can offer some advice here!

I have made quite a few liners. The last one I made with silk--very expensve but very nice. Usually I just look for inexpensive silky fabrics at walmart. I wrap the material around my hand to feel the warmth or coolness it might offer. I buy about five yards, fold it in half, and sew it together along the sides after hemming the ends. I use a french seam so that the raw edges or selvedge edges are covered and don't unravel. (sew the fabric together face to face--turn right side out--sew along the edges) If you have a woodburning tool you can cut some fabrics with it and it will seal the edges. You can get fancy and make a square footbox but it really is not needed unless you want to taper your liner to save weight--they realy don't weigh much though so a flat end is ok and usually more comfortable.


Use a new needle to keep from snagging the fabric. You might want to make one from inexpensive light poly/cotton on your first attempt--makes a nice summer sheet. If in doubt about a fabric or do not know what it is, wash it and hang it up to dry. If it dries fast it will make a good liner--if it takes forever to get dry it will not be very good as a liner. I have used light fleece and light wool to make spring/fall liners. I have made quite a few liners with different top and bottom fabric--wool/poly, fleece/ supplex, silk/wool, cotton/fleece--a warm and a cool fabric gives you a choice of which to sleep on or have over you. I nade one with mosquito net on one side but it is not very comfortable to lay on.


Have fun, keep it simple.

[Malto]

If you are doing this for warmth there are far more efficient ways of getting warmth to weight than a liner.

[SunnyWalker]

Grayfox: How much to make me one from 6 yards of silk from Walmart? I'll pay shipping too!

[grayfox]

SunnyWalker, The silk liner cost me $75 for the material which was on sale at the time from a fabric store. Usually it sells for $20-$25 per yard and you need a bit more than 4 yards even if you are short. I did once find some silk at walmart which was flawed but useable. But I have not found any there lately. I used to find silnylon at walmart many years ago but have not seen it there lately either. If your heart is set on silk, take a look at the Sea To Summit silk liner which sells for about $55 at Campmor, and can often be found on sale from camp supply places. It really is a good deal.

I have been considering doing some sewing for others now that I am retired but I am not quite ready to take on a new career just yet. My first product might be a design for a light and easy to pitch tarp which I have been working on. I like the designing part a lot more than the meeting a payroll and maintaining a supply line part though so I would really rather just sell the idea if I could. If I ever do decide to take on some sewing projects WB would be the first to know.

[Kraken Skullz]

I am really looking to find something that is light enough to carry if my synthetic bag isn't warm enough and to help protect the inside of my bag from getting dirty on those trips where you just set up camp and crash after a long day. Any alternative suggestions are welcome if anyone can think of something different.

[daddytwosticks]

I'm a very restless sleeper. For this reason, a sleeping bag liner would have me tied up in knots. Sleeping bag liner pro's and con's have been discussed here before. Many advocate using "sleeping clothes" or clean base layers to sleep in. Not only will these keep the bag clean and extend the comfort (warmth), but they can also be used as spare clothes to hike in or hang around camp in.

[Dogwood]

On the cheap, pared with a synthetic sleeping bag, try a SOL Emergency(about 3.5 oz, folds up into the size of an orange) or SOL Thermal (9oz) bivy. Use on the inside of your sleeping bag or on the outside for additional sleeping bag warmth, protection from the elements, and on the inside as a pseudo VBL(it's really not but it might help to somewhat think of it that way). The SOL Emergency bivy is about $14-17 and the Thermal is about $5-6 more but the Thermal gives you greater warmth and greater durability. If something like this appeals to you and you want to DIY in the future you'll have a better understanding of what you want in a DIY project. making a DIY bivy is one of the easiest DIY projects.

http://www.rei.com/product/813511/so...bivvy#specsTab
http://www.youtube.com/watch?v=Nk_PM_XD2EE

[Dogwood]

The SOL Emergency bivy wouldn't be durable on the inside of your sleeping bag if you toss and turn alot.

[Dogwood]

Take along some iron oxide Toasty Toes or Heat Max Hot Hands or Heat/Body warmers. Drop a few in your sleeping bag. These can add a few degrees of warmth for about 6 hrs. Don't unseal until ready to use because they activate when exposed to oxygen.

[Kraken Skullz]

I really like the Sol bivy, just worried about the comfort. Do you have a link to the thermal?

[Venchka]

I really like the Sol bivy, just worried about the comfort. Do you have a link to the thermal?

The Thermal is listed on the REI page for the Bivy that Dogwood linked to above.

Wayne


Sent from the State of Delerium.

[Kraken Skullz]

I saw that after I posted. I checked out some YouTube videos on the different ones but those don't seem too comfy. I might try a lightweight fleece or something else to go inside the bag instead of a bivy type system.

[Just Bill]

For warmth- you are generally better going with clothes as Malto cryptically hinted. I have used the liners (sea to summit) Merry mentioned, but they are easily 5-10 degrees lower than rated. I own them as a summer sheet type item, so easy enough to add it to a bag for a few more degrees when needed. They are great for summer, and I still think a late april starter would be fine with a bag/liner combo for a thru.

That said- A good long underwear top and bottom will serve you better from a warmth to weight standpoint.
Fleece is okay for cost and weight- but too bulky for most folks to bother with. Again- fleece top and bottom would be a better choice.

For keeping clean though liners make sense-
Lots of folks like silk- I don't because of the price- but if you do...the popular place for cheaper silk is Thai Silks http://www.thaisilks.com/
To split the difference- Wally World and Jo-ann occassionally has a Polypro or similiar type fabric that looks a bit like a Capiline 2 type fabric for a few bucks- cheap but a bit heavy, and would provide a 5-10 degree bump to your bag.

The best liner material is...liner material. (synthetic silk)
M50 (the one I make quilts from) seems to be out of stock but M90 works well enough- http://thru-hiker.com/materials/breathable.php
There are other fabrics out there that are in the .7 oz per yard range but 11-12 per yard.
This stuff would be fine for a liner- I haven't used it personally- http://dutchwaregear.com/ultra-light-argon-fabric.html
But as mentioned above- 5yds will do it and you can make a 4-6 oz liner that would be very easy to wash and dry-even on the trail.
A cheaper version is uncoated ripstop (1.1 oz)($6-9 yd). You can find 1.9 oz uncoated at many fabric stores and with a coupon get it for $5 or less per yard.

[Kraken Skullz]

I'm starting to wonder if tyvek would provide any heat retaining properties. I have some construction sites around and I figured what they don't use I could wash to reduce the noise and use to retain heat as a bivy.

[SunnyWalker]

Thanks Grayfox. I don't know why I did not think o Campmor. Headed that way.

[Snowleopard]

To increase warmth, you have to add real insulation. A silk liner will keep your bag clean, but will only add a small amount of warmth -- think of sleeping in a cold room with just a sheet, no blanket. For a DIY approach to adding warmth, make a quilt of two sheets of silk or nylon sandwiching a real insulation (e.g., Climashield Apex, http://thru-hiker.com/materials/insulation.php ). If there is enough space in your sleeping bag to use it inside without compressing any of the insulation, use it that way; otherwise make it bigger and use over the bag.

For silk at cheaper prices, as Just Bill says, thaisilks.com, also dharmatrading.com ( http://www.dharmatrading.com/fabric/...i-fabrics.html ). People use Habotai silk. The weights are in a funny unit (mm=momme; 8mm is about 1 oz/square yard).

[Just Bill]

Yar- Tyvek (or any bivy) will add a few degrees of warmth but this is in comparison to cowboy camping. A breezy night under a tarp or in a shelter would also be a decent example.
It doesn't make you warmer, but it does stop you from getting colder.

To that extent if you can piece one together for free it's nice to have. A roll of tyvek tape is $12 these days though so not totally free.

Mylar space blankets will make you a bit warmer by reflecting any heat that radiates out of your bag. Also the sun reflecting bubble wrap that people make cozies out of or occasionally use to protect thier dashboards is a cheap couple degrees. (Hammock using silly heads use them as cheap pads )

As someone that builds houses and gets real pissed when the last 20' of my roll goes missing and I have to go buy another $120 roll- ask for a piece. You don't want to scrap together a bivy from cut offs. (ground cloth is fine)
Make sure it's tyvek- The other stuff is different.

[Meriadoc]

Hmm. Most on this thread are taking a different approach than I am. I'm thinking about vapor barriers not insulation. Rather, I'm experimenting with vapor barriers until I get them to work right!

In warm conditions of 0 to 20 F I have had considerable success with clothing that is a partial vapor barrier i.e. Goretex (eVent let vapor pass through too easily to provide warmth). That goretex worked so well was pretty surprising to me. But it has made me want to try a partial vapor barrier in a sleeping bag too. The idea being to increase the humidity next to the skin thereby reducing evaporative heat loss and also reducing the vapor that would pass through and get caught in insulation layers.

Thus my idea to try DWR coated windproof nylon. It's not a complete barrier but it retards vapor transfer a good bit as I know from my wind jacket.