Pack Liner as Compression Sack

[Tim Garner]

After doing some searches here, I didn’t find an answer to this question.
I have trouble getting all my stuff in my current backpack, along with my 20degree top and uderquilt for my hammock.

I use a nylofume liner bag. I twist it tight after pressing as much air out as I can and stuff it down between the liner and backpack.
But I believe the nylofume allows some air back in as the quilts try to expand.

I’m wondering if one of the light weight, roll top type drybags would resist letting some air back in.
Or maybe a taped, DCF dry bag. I’ve made a few of those now.

[Nicholas P]

What I do is I don’t twist my nyloflume liner  I just get the air out and fold it over in such a way that I can put more gear on top and continue to compress the air out as gear is added( air will still come back in but it will also go out) , then I  recompress everything by pushing down with the packs roll top, sometimes If it’s really full I have to use the roll top to compress and then unroll to add the last bit of gear and repeat. I wouldn’t do this if I thought there was a chance my pack might get fully submerged  but otherwise I have not had any issues with water finding it’s way into my liner but I should mention my packs are also made out of waterproof materials to begin with so that helps .DCF packing cubes can also be a good solution as they are not air tight and allow you to squeeze the air out in the same manner ( actually probably more easily).I might add though that if it’s becoming a hassle and you are finding you are having to super compress your down to fit everything in you may consider a slightly larger volume pack as it will save you time and your down will thank you for it .

[David D]

I broke a nylofume using it as a compression sack while packing up.  They’re not really meant for that.

I moved to a 13L sea to summit Ultra-Sil @ 1.5 oz penalty, but some peace of mind.  No air gets in.  The 8L is 1.2 oz so the 13L one seems like a nice sweet spot.

[Tim Garner]

Nicholas, those are the very things I have been doing. Just considering other possibilities.
And yes, as soon as I can come up with the cash, a little bigger backpack is in my future.

David, I am looking at the Sea to Summit liners and the Six Moons.
But I may make a DCF wit seams sealed. I can buy the DCF and tape and do it for a pretty reasonable price.
I’ve made several dry bags, including a couple square bottom bags.
The square bottom bags may increase the chances with its extra seams though.

[Terran Terran]

I’ve used tight fitting HMG pods. The air releases through the zipper, but with the zipper against the pack material, it works like a 1 way valve. While they’re not completely waterproof  because of the zipper (endpoint), they’re pretty well sealed off when inside the pack, especially if you use more than one.. A little expensive, but they can help breath new life into an old pack.

Folding your liner instead of twisting to seal it off will more or less work the same way.

I’m not sure what happens to down when it’s compressed. It can clump up. It can shift, leaving bare spots. You’ll need to shake it more. It gets worst if left for a long time in the same position. I find it easier and quicker to set up camp if it’s not compressed. It may take longer to warm up. When you loft it up, you’re drawing in cold air.

[Nicholas P]

I agree HMG pods are nice because they are shaped perfectly to fit into a lot of packs without any leftover space and yes they are also expensive, fortunately there are a lot of cottage makers making packing pods these days and most come in quite a bit cheaper than HMG. while most are just boxed shaped ( not curved ) and not always seem taped like HMG’s are, I don’t think those things are really necessary , if you  find a size that’s slightly bigger than the inside circumference of your pack they will nicely conform to the shape of the pack anyway. If you  are interested in going that route I’d recommend taking a look on Etsy to save some dough.

[Tim Garner]

Interesting, “Folding your liner instead of twisting to seal it off will more or less work the same way.”
I’ll take a look at pods on Esty.
Thanks.

[Nicholas P]

Tim, “folding your liner instead of twisting “  was exactly what I was describing in my first post, sorry if my wording wasn’t very clear. This I think is probably the simplest cheapest solution especially since you have not one but two quilts to pack , both can go in the liner with less fuss than having to individually pack into cubes. Cubes on the other hand may be slightly easier to squeeze the air out and are a bit more durable but I find nyloflume to be surprisingly durable and they are cheap and easy to replace. Also there is a guy on Etsy that sells pad adapter valves to convert your liner to a pump sack but I guess that is not relevant to this thread since I assume you are not using a pad.

[Brian W]

When I went on one of Skurka’s backpacking trips, we used trash compactor bags from Costco. And I’ve used them ever since.

[Jason]

The Sea to Summit UL Pack liners are backpack shaped, around the same weight as a compactor bag, and have a roll top / buckle closure.  I did the compactor bag thing for a couple/few years, but like the option of packing it outside of the pack if I choose to.  There’s also significantly less excess fabric to deal with inside and overall I’d assume sil is more durable than a trash bag.

I think I have the 35L size –

https://seatosummit.com/products/ultra-sil-dry-bag?variant=42126660731053

 

[Tim Garner]

Actually, I do use an insulated air mat, one of the lighter EXPEDs.
I’ll take a look at using the inflation bag but, I’m not sure if it’s big enough for what I usually put in the main liner….. two quilts, hammock, a small pillow, air mat and a few light layers.
I could use another dry bag for the layers.

[David D]

>I could use another dry bag for the layers.

Ya, that’s what I use the smaller S2S ultrasils for.  Awesome for that. I keep my bag in the Nylofume but don’t compress it too much because repeated cycles affect the temp rating over time.

[Nicholas P]

Using your existing pump sack is an option, but what I was talking about was actually using your nyloflume liner as a pump sack by installing a valve adapter onto it. I found one on Etsy for a Therm-a-Rest ,I’m not sure if he makes them for an Exped though . I have not actually used it yet so I can’t say for sure how well it works as a pump sack but I have no reason to believe it won’t work at least as well as the crappy one that came with my Thermarest. I plan on using it as my liner and my pump sack to eliminate having to carry the additional pump sack.

https://www.etsy.com/listing/1378373492/thermarest-winglock-valve-sleeping-pad

“I could use another dry bag for layers”
-I put my sleep system in the nyloflume liner and my extra clothing in a DCF packing pod.

[JCH]

Surprised the Exped Schnozzel has not been mentioned…it’s been my go-to pack liner/pump bag for years.

[Nicholas P]

Yeah from what I hear the Shnozzel is a great pump sack  and probably a great option for the OP . As a Therm-a-Rest user I have no experience with it other than wishing Therm-a-Rest would make something similar.

[Tim Garner]

inflate my air mat a little on the soft side so it conforms to my body.

With the Shnozzel, it takes two and a half bags to get it done.

 

[William Chilton]

As a Therm-a-Rest user I have no experience with it other than wishing Therm-a-Rest would make something similar.

If you cut the plastic connector out of the inflation bags that come with the Therm-a-Rests, after clicking it onto the wing-lock valve, you can click the Shnozzel (or other Exped pumps) into the back of the connector. It’s easier to connect the connector to the pad and then to the Shnozzel, rather than the other way round.

It might be a bit tricky at first, but gets easy when you’ve done it a few times.

[Terran Terran]

The newer Schnozzel works well on Thermarest by fitting it around the Thermarest valve.

[Dan]

Just curious why you bring an inflatable sleeping pad with a hammock. Do you alternate between hammock camping and using a tarp? Sorry if this is a naive question, as I’ve not really learned much about hammock use since I’m generally above timberline.

[Nicholas P]

Great info on using the Shnozzel with the Wing lock valve.It’s good to know it can be done without performing surgery on the Shnozzel.

I figured I should go ahead and test out my Etsy purchased nyloflume to wing lock valve adapter. I’m happy to report that it worked flawlessly, I was able to fill my regular/wide NXT in just 3 pumps.It’s definitely going to require a bit more babying  than the Shnozzel would but I’ve had pretty good luck with nyloflume so far and have used them to inflate pads before just without the ease and speed that the adapter provides. It slides on and off the valve so much easier than the Therm-a-Rest sacks adapter does and if you happen to blow out your nyloflume it’s super easy to install on a spare one. You just cut a hole in it and it screws on sandwiching it between the two plastic pieces.

Nyloflume liners are pretty Darn light and take up very little space  so It’s really not a big deal to carry around a spare especially since they are a multi use item.They can even serve as a backup to your odor proof food bags if you have one fail.

[Nicholas P]

I should also add that a little packing tape on either side of the bag around the whole as reinforcement is a good idea and is recommended by the seller. Also the adapter weighs only .4 ounces and I believe nyloflume bags are .9  so with one bag you are  coming in lighter than the Shnozzel (2 ounces for the UL medium)and with a spare bag you would be just a touch heavier.

[JCH]

…with one bag you are  coming in lighter than the Shnozzel (2 ounces for the UL medium)and with a spare bag you would be just a touch heavier.

Ah, but with the Schnozzel you don’t need a spare. Or an adapter.

[Tim Garner]

Dan, I have used an insulated air mat in my hammock for a lot of years. Mainly because, when lightly inflated, it conforms perfectly to my back, particularly my lower back. I have some issue with my lower back at times.

The hammock feels great but with the air mat, it’s like laying on a cloud.

And, I’ve never had CBS (cold but syndrome).

Always in my hammock with tarp overhead. Occasionally, when no rain is expected, I leave my tarp in it’s tarp sleeve so I can see the stars.

[Terran Terran]

A Schnozzel isn’t waterproof.

[Nicholas P]

Ah, but with the Schnozzel you don’t need a spare. Or an adapter.

I don’t think you would necessarily need a spare nyloflume liner either, I’m reasonably confident in their durability , I’ve been using the same two bags (2 because I  use  one in my day pack ) for years without issues.
I was just pointing out for the people that may have less confidence in their durability that you could take a spare for  a negligible weight penalty and now you have another bag that can be used for various other things.

what you see as a negative I see as a positive. Redundancy is a good thing if it’s not heavy.

Also with a Schnozzel you need a Schnozzel.

Schnozzel: 45 bucks

Nyloflume liner : around 2 bucks

Adapter that can turn any bag into a pump sack:  Priceless ( kidding I think it was around 15 bucks).

Also as Terran pointed out Nyloflume is more durably  waterproof unless it gets a hole but then you can replace it for two bucks unlike the  Schnozzel .

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