Can Pack Liners Replace Dry Bags?

That liner is a dry bag, you don’t need more dry bags inside of it. Packing clothing and bag/quilt loose will allow you to maximize use of your space by filling every little nook and cranny, and also compresses your down gear only as much as needed. And your down gear should either be in the pack or on in use, generally you won’t need to be carrying it outside the pack.

Yes. You only need the pack liner to keep your stuff dry.  And yes, your stuff will fit into a smaller pack if you just stuff everything into the pack, instead of using stuff sacks.

Welcome to ultra light :)

I would never trust cuben as a dry bag. I have seen someone get his sleeping bag damp hiking in the rain with a well used cuben stuff sack. He tested it at home after the trip and said it was leaking badly.

Thanks for all the advice, gentlemen. Much appreciated.

I would not use a pack liner. I have used many trying to make them work, they always leak after a few days. None has ever stood up to a week long trip, for me. I have used trash compactor bags, garbage bags, a purchased bag, large sized turkey baking bags, and a MYOG vinyl bag. At some point within a week, they all developed a leak and let things get fairly damp. The best was the MYOG bag made from some PVC coated fabric I had kicking around. It lasted 5 days.But, it weighed about the same as two of my more traditional dry bags. And, I needed one dry bag for use as a bear bag/food bag anyway.

For three season hiking/camping, I use a combination of three bags: 13L dry bag/bear bag (~3oz), a small rock sack/ditty bag(~1oz) and a small, Sea to Summit eVent/compression bag (~4oz.)  The first two are given.
Rationale:
After buying a set of expensive cuben(DCF) bags several years ago, their overall durability was poor. They did not last a single season. After tree trips, and in a three day rain storm with brief interlides, my sleeping bag was wet near my face, my down jacket had a wet back, and the rock sack had as much tape on it as fabric. My oatmeal packets were wet, one was getting moldy, and my candy was a sticky mess. So, I went back to my 13L PVC coated bag, a cheap wally world rock sacks (they get chewed up) and bought a medium dry/compression bag for the rest of the year.

I went through a couple garbage bags as liners (lots of small holes) and a compacter bag (slit on one side as I pulled my pot out). I bought a commercial liner and it lasted a day as I caught it on my buckle and tore it. I had paid $39 for it and I just ruined it. I made one that worked well till the last day on my second trip out with it. I slipped my saw behind it and put a jagged tear in it near the bottom. This got worse over the day and was pretty much useless by the end of the trip. I bought a small eVent bag to protect my down bag. I later used this bag for most trips, and still do after 8 years. So, in two years I went through a half dozen or so liner bags, and, ended up using dry bags with them because they all had leaks or holes in them. Only the MYOG liner lasted a full week out, but this was heavier than just the compression bag, anyway.

Sooo, I evaluated my gear for “wet” sensitivity. Batteries? No (sealed in packets.) Lighter: yes. Down: yes. Long Johns: yes. Sleeping socks: yes. Tarp: no. Pot/lid/spoon: no. Stove: no. Cord/stakes/rock sak/DEET/AM drops/water bottles/fishing gear/rain jacket/etc: no. Only my sleeping gear, down jacket & food needed to be dry! My bear bag/dry bag covers my food. Would the rest fit? Turns out it would, just…. So I packed it all into a small eVent bag and compressed the heck out of it…down to a 11″ long and 5″ diameter waterproof compression bag. Just small enough to fit into the bottom of a Murmur.

I took this out canoeing and flipped the canoe getting in off a dock. Everything got dipped in the lake. When I got to camp, my sleeping gear was still dry and my food was still dry. I got a fire going and changed into my sleeping cloths. It was all good. Even my neoair only needed some wiping with my bandana (dried by the fire.) I never went back to a liner. And the dry bags also acted as some flotation for my pack…it didn’t sink.

For the ~4oz penalty, I could use this all the time. Last year, I spent a week straight in rains, drizzle and storms. Only my sleeping gear was dry (well, it was a little damp, but an hour of laying down with it dried it out.) It weighed less than the MYOG liner and WORKED for around 8 years with no changes…quite durable. It did not develop holes, or, other leaks. A small tear in the food bag was patched with some thread and super glue. Still using the same bag.

So, no, I don’t use liners and do not recommend them. They lack enough durability to finish a two week trip out. And, they cost a LOT more with the durability issues and changing them constantly. The trash compactor bags were ~$.50 each, good for one trip. The commercial one was about $39. The MYOG one took a couple hours. All wasted… A set of dry bags and eVent bag was less than I spent on all the liner “tries” and works better. I flip the eVent bag inside out and stuff it with whatever as a pillow. (even wet leaves or pine needles work.)

For a few bucks you can get trash compactor garbage bags. They are near indestructible and weigh about 1 ounce. They are easily big enough to line a 65 liter pack. I have one that has seen 6 years of regular use and is still totally waterproof. Just make sure to twist the top closed and tuck it down inside your pack and then you have no worries. I have totally submerged my pack on kayak trips and my bag and down gear are always bone dry.

I started out with trash compactor bags and they worked fine as liners. I was kindly given a pair of nylofume bags from a fellow BPL”er for the wife and I and have used them from the start of this season and I find them quite bullet proof. They also do double duty for blowing up our inflatable pads so that probably puts more stress on them than lining the packs. They weight 50% less than the trash compactor bags and seem to be more durable.

Keep in mind a TRUE dry bag will be secure from water penetration totally submerged as used on water craft. A lot of the lighter type dry bags such as the STS dry bags have a warning against submersion. Of course makeshift liners like the trash, compactor or nyloflume bags have their limitations as well. If your pack does end up submerged from a fall into a creek/river etc. you have to understand  these liners may take on water. On the other hand the lighter dry bags work fine for food bags and non submersible uses.

A big part of how well UL equipment may or may not work for an individual is subject to how much abuse it will likely see. Sometimes that can only be determined through actual use.

Thanks for the interesting discussion, everyone. I’m looking forward to testing out some of these options.

I tried a pack liner for about 1 season. Went with the nylofume option, tried the compactor route too.

Compared to dry bags, i found it more annoying to pack and unpack.  I didn’t like having to pull everything out to get to my sleeping bag, and having a pack explosion. If I have things in dry bags, then i just yank dry bags out and set them aside, and my dry layers are still contained until I set up my camp and can change into them. i also found it annoying to try to shove everything back in, and get the top of the bag twisted and secured deep in my bag. Everything took up more room, but then it was harder to get the bear can in.

If you like organization ,  the pack liner may not be for you.

not for constantly wet environments … youll still need a separate dry bag for yr down bag/poofay

imagine rain … lots of rain … non stop rain for days …

each time you need to take out some insulation some moisture will get in …

now imagine you are putting away and taking out that nice fuzzy fleece … that fleece will get damp perhaps wet … and itll be going in the same pack liner as your sleeping bag …

etc ….

;)

I use a pack liner. I still put my clothing in an over-sized cuben or silnylon stuff sack for a little added protection and so that I know where certain things are. When I say over-sized, I mean that when filled, it is still squishy so that I can cram it into any void. The only true dry sack that I have is for my food so that no liquids can get into my pack (if packaging failed on something like hot sauce/olive oil) and also used to hang my food when needed.