Millbank bags for BOB water purification?



in the past when backpacking/wild camping etc I have used these to get clean water, my method is to let the water run through the bag, then boil it or use a water purification tab, I liked it because it was simple and easy, and it never made me ill so I assumed that it must work, although I’ve never seen “millbank bag” on anyone’s BOB list, is there a good reason for this? 


  • Comments (6)

    • 4

      I personally have never heard of one of these before. It looks like there is a USA company that makes them as well — millbankbagsusa.com. I prefer the design of the UK version though. 

      In The Prepared’s water course, they go over how to prevent drinking muck through various ways such as making an improvised charcoal filter, straining through a bandanna over your bottle, and a technique for how to extract the water from the source to prevent as much gunk as you can. While I do see why the millbank bag could be valuable, especially if you are in some nasty water, I had always planned on improvising a pre filter with a tshirt or bandanna. 

      • 3

        Olly, you have to remember though that the canvas of the millbank bag is going to be a tighter weave than your tshirt and bandanna, so you will get better filtration and extend the life of your water filter further using a millbank bag.

    • 4

      Had to use one once; during jungle training in Brunei. Only had access to swamp water (jungle camp literally in the middle of a swamp) Took an age to filter and looked a bit grey but I didn’t go down with anything. Old School but effective, didn’t make too bad a cup of tea either.

      • 4

        Thx for the reply, it’s reasuring to know that they work and that it wasn’t just luck that meant I didn’t get ill

        although the thing that I did think, they wouldn’t be much/if any protection against chemical contamination so maybe I would be better off investigating a more modern water filter and keeping this as a backup?

      • 3

        Dave69 if I was going through the jungle, I for sure would use a millbank bag. You need every level of filtration you can get.

        LadyKaos remember that the millbank isn’t taking out any chemicals, bacteria, or viruses, it only filters out the sticks, bugs, leaves, and dirt larger than the weave of the fabric. It makes your water look and taste nicer and extends the life of your water filter because you aren’t getting those sticks and dirt into the filter, but that’s about it. There isn’t much use for a millbank bag in a crystal clear mountain stream but there would be in a dirty mud hole in the jungle. 

        You do and should invest into a modern water filter, but even those will only filter out bacteria and sometimes viruses. The Prepared has a great article on water filters that you should take a look at. https://theprepared.com/gear/reviews/portable-water-filters/

      • 2

        Quote Bradical – “remember that the millbank isn’t taking out any chemicals, bacteria, or viruses, it only filters out the sticks, bugs, leaves, and dirt larger than the weave of the fabric”

        Yeah, got that, I haven’t been out wild-camping since high school and I wasn’t so careful then, I usualy filtered the water through a millbank bag then dropped a purafacation tablet in it. So the bits were filtered out and germs were killed, but now I’ve researchd it a bit more, most modern water filters are designed to remove chemical contamination to a certain level as well

        Thx for the link 🙂 I’ll check it out