I usually use a pack cover in the rain. But I also have stuff sacks then in my pack for sleeping bag and clothes for added protection.

A pack liner would certainly save weight but I'm concerned then with haveing a wet backpack that will get heavy and soaked with rain...right?

The packliner will take quite a beating with you stuff all your things in it. I had the same thought last summer and switched to a liner. It started leaking pretty quickly.

Yeah, i never really thought about that. You mean like things puncturing it?

I've used a pack liner for years -- took a dunking while canoeing once -- and not one drop of water seeped in. A pack cover would have been completely useless.

To me, it's not so simple as to one being always better than the other. There are different factors to consider:

How do you pack?

Do you frequently need access to the main pack? Or do you place frequently-used items in various outside pockets? If the former, using one big liner will be a hassle. If the latter, then the one big liner method can work beautifully. I line my pack, place most everything inside, then twist it tight (and rubber band if canoeing or doing serious stream crossing). Items like first aid, snacks, camera, etc. are placed in different outside pockets protected by ziploc bags.

What kind of pack do you have?

As stated, packs with multiple pockets will be easier to use with a liner than packs with just one big compartment.

The oft-repeated mantra about a pack getting soaked in pounds of water really applies less and less with modern pack materials. A cotton canvas pack from the '70s will absorb a lot of water... but modern cordura, dyneema, silnylon, etc. will absorb very, very little. Don't forget the water that can collect at the bottom of a pack cover! Sure, many pack covers have drain holes, but somehow, the water never drains out completely for some reason...

But what about durability?

Don't use trashbags. Even the so-called extra heavy duty lawn and leaf bags are only rated 1.1 mil. In contrast, a contractor bag has a 2.0 mil rating -- which is twice as tough! While super big and tough, a 35-gal bag weighs just 2.5oz. Don't forget that a liner is protected inside your pack whereas a pack cover is subject to scratch and abrasion outside!

Given the variation in pack design, pack material, and hiker preference -- both liners and covers will continue to exist side by side. :)

Interesting! I use dyneema packs. I live in PA and do a lot of backpacking in Alaska. Both areas get a fair amount of rain. (Alaska almost everyday!) I was just worried that my pack would be soaked, heavy and annoying. You say it's not huh? I do like having some piece of mind if I dunk my pack out of a canoe pr kayak. I purchased some pack liners from Gossamer Gear. I will try them out.

Hi Evan:

My view... if a pack absorbs water -- it's going to be mostly the "foamy" parts -- shoulder straps and the padding on the back side. Those are the areas where a pack cover will offer little to no protection! But again, much depends on the design and material of your backpack.

I hate to keep tooting the horn in favor of aarn packs, but they make my packliner perfect like ben said. I keep all my non-frequent items stowed in a trash contractor bag, and store the following in my front pockets:

Stove, pot
1 liter of water in each pocket
camera
map
gps
lots of food
first aid
tarp
stakes
and i still have room

the liner makes things dry, gets rid of the need for stuff/dry sacks, as most my gear compresses into the bag itself nicely, which allows my weight to go down.

Edited by isaac.mouser on 05/23/2010 13:50:30 MDT.

Pack covers are not waterproof either in heavy rain (rain runs down your back, soaks into pack) or in case of immersion.

Stuff sacks are not waterproof, either (stick one in a partly full bathtub and see what happens!).

For quite a while, I used a pack liner (2 mil trash compactor bags). However, I got tired of fighting the slippery thing every morning--I would shove a small item down in the bag to fill a spot and it would pop right back out at me. The other problem was that at about the same time I ran out of the supply of trash compactor bags I had bought several years before and couldn't find any new ones that were unscented. (Not only was I worried about attracting bears, but I couldn't stand the stench myself!) The contractor bags of course solve that problem.

Now I use a large Sea-to-Summit Ultra-Sil dry bag (13L) for my sleeping bag, extra socks and base layer and a smaller dry bag (4L) for my insulating outer clothing. Anything else is either packed in plastic or won't absorb water. This setup has survived my slipping and falling in a creek during a difficult ford. There were several inches of water in the bottom of my pack, but nothing got inside the dry bags. I tested the dry bags in the bathtub when I bought them (these bags used to have a leakage problem) and retest them every year--no problems. The two dry bags together weigh about the same as a pack liner.

I do use a lightweight (1 oz.) pack cover over my pack, but that's because my pack is the basis for my pillow, so I'd like to have the front of it reasonably dry. Silnylon and dyneema, though, don't soak up water, so I suspect the pack cover isn't really necessary.

Edited by hikinggranny on 05/23/2010 18:26:27 MDT.

Very interesting comments on the Sea to Summit liners which are discounted perhaps in response to bad reviews. Please tell me about your tests? And a 1 oz. pack cover? Details please. I'm trying to parse this and it is very multifaceted. Thanks, John

Those Sea-to-Summit Ultra-Sil dry bags aren't functionally waterproof either. Low HH.

I tested my Sea-to-Summit Ultrasils by turning then inside out, filling with water, and leaving hanging for 20 minutes. Not a drop! That was in 2008. It appears that Sea-to-Summit made a bunch of changes after all the reviews about their leaking!

I am not about to trust my precious insulation to anything that won't pass that test!

For something to take on a water trip (canoeing or kayaking), of course you want something that will take at least an hour's immersion, probably under pressure. I doubt that the S-to-S Ultrasils will do that.

Edited by hikinggranny on 05/23/2010 18:37:08 MDT.

So where and when purchased? Any observations about seams in light of previous analysis that inside seams were not taped or unsealed? I assume as liners no exposure to treatment outside the pack given fragility? Thanks much! John

My S-to-S bags were purchased at REI in early summer 2008. I bought them there so I could take them back if they leaked! I still will if they start leaking in the next year or two. The seams are taped and so far no sign of peeling. I don't use them as liners but instead of stuff sacks for my critical insulation (sleeping bag and outer clothing).

The bad reviews were in 2006 and 2007.

Edited by hikinggranny on 05/23/2010 18:43:06 MDT.

Re S-T-S dry bags, I have read atrocious reviews -- but as Mary stated, they were in 2007. I've heard nothing but good things since then -- so S-T-S must have revamped their dry bags.

But for me, I really like using contractor bags because:

1. they simply work!
2. they are sized generously.
3. they are cheap as heck.

The big thing in the 2006 (Jim Wood) and 2007 (BPL) reviews was that when they tried a similar test to mine, the water leaked through pores in the fabric!

I had none of this in 2008. I believe this is an excellent instance of a company watching for reviews and responding to them. I hope so, anyway!

On the other hand, the issue of dry insulation is critical enough that I wouldn't use anything without first testing it myself!

I have used both compactor bags and STS sil drysacks. The compactor bag did not hold up on a 6-day trip, I had about 3 holes in it by the end of my trip. Maybe I was too rough with it? The STS drysack has been great, no issues with leaks or durability.

sort of a random topic for a first post...I've been a lurker here for awhile, but here goes.

I have an Sea-to-Summit sil dry bag that I use for my down sleeping bag and MB UL down jacket. I've sort of just assumed it was watertight, and never tested it. The packaging the thing came in suggested that it's not rated for immersion, but I took that as a recommendation for it not to be used for CONSTANT immersion.

Anyway, it's kept my stuff dry in long constant rains, but I've never given it a good "fill the thing with water" test, so I figured I'd give it a shot.

Sitting upright with the roll-top up, no leaks. The taped seams are all watertight, and the fabric did not seep. Lying on its' side, the roll-top leaked slowly after about 10 minutes or so, once the water worked its' way through the rolled closure.

So, is it technically 100% watertight, no, but for the usage we're talking about here, it's plenty waterproof, and I'd say more so than just a pack liner.

I keep most of my other stuff in ziploc bags inside my pack, so no need for any other cover/liner, etc.

What are you guys doing to your trash compactor bags? I have been using the same one for 3+ years (6-8 trips/year). No rips, tears or leaks. I am not overly protective of my gear either, not abusive just not overly protective.

I tried the trash compactor liner and it served it's function as being water proof, lightweight and inexpensive. But I gave it up due to the frustration of trying to find anything in my pack with this liner collapsing and folding over my contents! As was mentioned in an earlier post, I use the "everything in the main compartment approach." I can see where they would be more satisfying in a multi-pocketed pack.

Pack covers simply do not work, IMHO.

I exclusively use a DIY poncho that covers the pack and am completely satisfied. Note however, that I hike in forests, not in gale force winds above the tree line!

What size liner do you guys use? I use one thats 28" tall with a 14" x 7" rectangular bottom. It seems like most "pack liners" are too big for UL packs.