Comment by mauvehaus | Hacker News Reader

Comment by mauvehaus | Hacker News Reader

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The coatings are an almost complete waste of time on something with as many seams as a pack. Get a trash compactor bag, and use it as a pack liner bag. They last forever and do a better job than any woven fabric with a coating.

Bonus: they're usually white, which means you stand half a chance of being able to see the stuff in your pack. White is pretty rare except for Dyneema packs (Dyneema apparently doesn't dye).

Edited to add:

The other major failure mode for coated and laminated fabrics is when they tape the coated or laminated side. The seam tape flexes differently from the substrate fabric, which pulls at the coating or laminate. I've had coated and Goretex rain jackets fail in this way, as well as coated stuff sacks. Silnylon fares a little better because the silicone is impregnated into the nylon rather than coated on. Silnylon isn't breathable, so it isn't a mainstream material for rain gear though.

Source: GA->ME 2010 and another thousand or so miles of hiking.

I agree, I wish backpack manufacturers would just skip the coating. It would save weight and cost, and greatly extend the lifespan. I have multiple really nice packs that I can’t use due to coating grossness, despite being 100% functional otherwise.

They probably use it in part because it reduces fraying on cut fabric. Given how slippery nylon fibers are compared to natural fibers, I can see this being a huge benefit. I sewed a couple of duffel bags out of nylon and got no fraying at all on the raw edges as I was cutting and sewing.

That said, I'm guessing mostly it looks good to people who don't know better.

You can (now) get Dyneema color printed: https://ripstopbytheroll.com/collections/omnicolor/products/...

(I discovered https://ripstopbytheroll.com from a comment below)

I'm not sure what a trash compactor bag is made of, but I imagine it's intended to be disposable.

I recommend a pack liner made of a more durable plastic, as they have a couple of advantages in emergency situations.

1) They can retain air and thus keep you buoyant if you come to grief crossing a river. 2) Assuming you're using a large pack for multi-day trips, you can use a pack liner (and in my country they're designed for this) as emergency shelter if you don't have a bivvy bag or tent.

Trash compactors work by compressing the trash to reduce its volume. Due to this pressure, trash compactor bags are designed to handle these forces. This makes them much more durable than normal trash bags.

It's a classic ultralight hiker move [0] and is commonly the first suggestion in gear shakedowns on /r/ultralight.

[0] https://sectionhiker.com/how-to-keep-your-backpacking-gear-d...

Ah, I stand corrected. In that case, a trash compactor bag sounds perfect - if you can fit yourself in a sleeping bag inside one :)

We do the same inside portage packs up here in Minnesota. I’m sure there is a better way (at least there should be) for securing the opening, be we always just tie a knot.

Why would you use a liner bag vs wrapping the exterior of the pack in plastic (as in a rain cover)? Wouldn't that keep the whole pack dry?

Depends on your use cases :)

For me, a rain cover is a hindrance when I need to retrieve things from my pack, I have to remove it entirely, whereas a pack liner, I just need to unfurl the top of it.

Secondly, as there are very few bridges in the New Zealand back country, we frequently have to cross the channels of braided rivers. A rain cover keeps out water from above, not so much from below.

And as I mentioned in a previous comment, pack liners can, in an emergency, function as a flotation device or emergency shelter.

An exterior cover can’t keep the whole pack dry in heavy rain. Water can run down your back and soak into the pack that way. Things that really need to stay dry, need a sealed bag.

But you don’t need a liner for the whole pack, either. Cookware and stoves can get wet, and the tent is probably wet anyway if it is raining.

Typically only the food, sleeping bag, and clothes really need to stay dry, so you can just seal those each in their own bag. I kept those things dry for a month in the Pacific Northwest using just regular kitchen trash bags.

Using dry bags inside the pack means you:

  * Don't need to stop/remember to put the pack cover on.
  * Can use them to organise different things.  e.g. separate clothes from sleep kit.
  * Can use them to roll/squash the air out of clothes/bedding to take up less space.
  * If you need to remove things from the pack to look for items lower down they'll stay dry in their separate bags.

The trade off is a little more weight but it's generally < 100g-ish compared to a pack cover.

I use both. The stuff inside the liner bag is stuff that has to remain dry (extra clothes, sleeping bag, stove and matches/lighter, etc). Anything outside the liner but still under the cover is stuff I'd prefer remains dry-ish, but can get wet. I made my cover out of Silnylon; it weighs very little compared to the added peace of mind

I have a backpack (shout out to the REI trail 25, I've put it through an absolute beating over the last 4-5 years and it still looks and works great) I use for around the town kind of things, day hikes, trail work, etc that has a rain cover. They're alright, but it's a bit of a hassle to get it out and put it on the pack, and vice versa.

It's nice if I'm biking home with the pack on and it starts raining, but I don't bother if it's going to be a short light rain.

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