I have a Lowe Aline Attack 50 pack from around 2000 and recently much of the inside has accumulated a sort of brown powder that is either, I suspect, some kind of mildew, or the remains of the decomposition of the pack's waterproofing.

mysterious stuff in pack

The stuff is not easy to remove; if I beat the pack while holding it upside down, the dust gradually falls out. Wiping it down with a damp cloth or cleaner doesn't speed the process up much. The stuff appears to be only on the waterproof liner and, to a much lesser extent, facing surfaces. What is it? Can it be removed? Is it just time for a new pack?


Addendum-- I've already accepted an answer below but wanted to share that Lowe customer support concurs that the waterproof liner has decomposed.

lowe e-mail

  • 1
    When you wipe a spot with a damp cloth, what do you get? Does more of the lining flake off?
    – ab2
    Jul 8, 2017 at 16:52
  • 3
    From the picture, it looks like a film that's dry rotting away. I'd say it's the water proofing. Goretex is known not to last long. Jul 8, 2017 at 17:10
  • @ab2 When I wipe it, I get a discolored patch on the rag. In the seams, where the dust accumulates as something more like 'crud,' I can sometimes scrap some off. Jul 8, 2017 at 17:41
  • If it doesn't flake off when you wipe it, it may not be the waterproof lining. I'd try wiping it down gently with a damp cloth. Then, if you can, turn it inside out and store it in a dry place. And repeat. If it is the waterproof lining, you will find out by wiping. If it is mold, this should get rid of at least some of it.
    – ab2
    Jul 8, 2017 at 17:54
  • 2
    Looks like the water proofing is breaking down (delaminating). Store dry, cool, and not compressed to prevent. I had a North Face VE24 do that after 12 years so I took tent only to the local store and they called me back and said we need the tent poles and rain fly. I was like why but took them in. They gave me a new VE25 tent. I don't climb anymore but it is awesome car comping tent. Wash it inside out a few times and you still have a pack with no water proofing.
    – paparazzo
    Jul 8, 2017 at 21:31

1 Answer 1


As a tailor, I would say that it is either the water proofing is breaking down or if it contains a fabric glue binding two types of fabric together is disintegrating. This is almost impossible to cleanup correctly. Personally I would either use it as it is, if you could use it in some way that such a condition would not be a hindrance for your backpacking, or get rid of it.

You could consider a pack liner (like a large trash-bag inside the bag).

Personally, I would simply get a new backpack. Sorry.

  • 1
    Yup, that's definitely the water-resistant lining on the inside of the fabric breaking down. I've seen that a number of times. Jul 10, 2017 at 11:30

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