wow moment (pack cover)

Edit: I've redacted this post since I misread the OP's initial post, thinking it dealt with the issue of pack covers versus pack liners, when in fact he is referring to using a waterproof pack instead.

Derek,
you may want to read again the OP. slowly this time.

Waterproof packs are the way to go. None of this sorta waterproof ephemeral PU coating stuff, but an honestly waterproof fabric like hybrid cuben or the dimension polyant materials. I wish all packs were waterproof.

Oh yeah, my bad. I see my mistake…

He is using a fully seam-sealed pack now. I have no experience with those, so I can't comment.

Time to redact!

I bought an HMG pack a couple of years ago and will never purchase another pack that isn't waterproof. Granted, HMGS are not that light, but they are comfortable, durable, and waterproof. I use a pack liner for insurance. No stuff sacks, down gear, never had a problem.

I found that I would end up with water in my HMG. Perhaps a defect, but a word of warning nonetheless.

And I'd recommend waterproof sacks for sleeping bag and clothes even with waterproof packs. Opening packs in the rain or putting wet gear or wet food bags etc back in the pack means you will collect moisture in there.

…But if you use a waterproof pack liner with a theoretically waterproof pack, what's the point of having a waterproof pack?

To prevent pack itself from absorbing water, which could make the pack 10 oz heavier??

I don't know…just a guess. I wondered that myself. I have a pack made from xpac that is waterproof to 200 psi…but I still use a liner for my down stuff.

I also have a pack made from xpac (with 70D silnylon for extension collar and sides). The surface fabric of the xpac absolutely absorbs water (although not a lot)–so "waterproof" doesn't help with that.

10 ounces of water seems like quite a bit. A pack cover won't keep the padding dry, which is where most of the water is absorbed if it is 3D mesh. I don't think it is worth it.

You should be walking fast enough to dry it anyway :)

"…But if you use a waterproof pack liner…"

Not much in the way of pack absorption prevention…

"…But if you use a waterproof pack liner with a theoretically waterproof pack, what's the point of having a waterproof pack?"

Insurance on long wet trips for down garments. It allows me to open my pack in the rain if I have to get my ditty bag or food without getting my sleeping bag wet, as just one example.

Pack liners are very helpful when you have wet gear in your pack along with the dry stuff. That and things like maple syrup and down bags never have been a good mix :)

On behalf of about 3/4 of the residents of Vermont, thanks for promoting the use of maple syrup in ultralight backpacking. Two great assets you forgot to mention: maple syrup poured over your pack and sleeping bag will make them much less water-absorbent; and will virtually ensure that those pesky bears totally ignore your food bag hanging in a nearby (sugar maple) tree ;-)

> But if you use a waterproof pack liner with a theoretically waterproof pack, what's
> the point of having a waterproof pack?

It's called the difference between theory and practice.
Two lines of defence.

Cheers

Maple syrup is just my symbolic reference to any leaking sticky stuff loose in your luggage.

A waterproof pack may be needed for pack rafting or canyoneering, but putting your wet muddy stuff inside one will pretty much guarantee that everything will be wet and muddy.

I have yet to see a truly waterproof pack that wasn't like wearing a rubber log with shoulder straps.

Your camera gear and insulation still need protection and I don't care if my tent and cook pot get wet.

If you are worried about your pack weight going up due to rain, wear a poncho and get UL rain shell and pack cover all in one. At some point, you are just going to be outdoors!

No right or wrong answers here but, for comparison, my strategy is a bit different.

I make my packs out of uncoated nylon. Water runs through the fabric easily and the fabric dries quickly when the rain and sweating stop. I don't use a pack cover.

Things that need to stay dry go into a nylon stuff sack put inside a tightly closed durable plastic bag (e.g. a trash compactor bag) and carried inside the pack. I'm pretty sure my dry stuff could survive a dunking in the lake without getting wet.

I test and change the durable plastic bag as needed so I know I'm starting each trip with a reliably waterproof membrane.