Grandpa's Survival Shack: A Millbank Bag....Coarse Water Filter

Here's what wiki has to say

A Millbank bag is a portable water filtration device made of tightly woven canvas made for use out of doors.[1] They are light, compact and easy but slow to use.[2] The bag is filled with water, which filters through the canvas by gravity. It is useful for removing sediment and organic matter but the water will require further sterilisation before being drunk.[3]

Yes this is a coarse water filter...a Millbank Bag is old school and a very good weans to filter large quantities of water at one go... you will still need to boil or use some chemical water treatment to make river/stream water safe to drink... but here is your first practical lesson in acquiring water...

it looks simple but its an elegant design. The hanging hole is opposite the ―toe of the sock shaped design causing it to hang ―toe down and allow the water filtering through it to be received accurately into a receiving vessel.

Before use its important to soak the bag to swell the fibres – soaking it in the stream or a can like this is fine and squeezing it a few times after a good soak works well... the idea is to make the fibers swell giving you a better filter

Although its normal to attach a simple cord to the bag, I use a carabiner so that I can tie the cord on, fill the bag from a stream and then quickly clip the bag in place (its heavy when full and you end up needing three hands to hang it.)
to fill the bag (I like to put it so the mouth faces up stream and let water do the work) and clip it in place

Let the water run out onto the ground until it finds the black line and then put the receiving vessel under it ( you do see the black line in the picture right?)

once you reach the line slip your water catchment container under and fill it up...What we have at this point is coarse filtered water. We have not removed any organisms. Since we are going ―low tech here a good rolling boil will do the trick....

There you go... Grandpa's trick to Coarse filter water...

Once again great post!!! Where could one find such a bag? (Didn't see the black line )

Doh!!! there's the line under the tag

Another informative post.

I think our Grandpa Dave should be bestowed with the the "subject matter expert" tag for the Survival forum.
Or maybe his own sub-section, like the "Conpiracy Professionals" forum. It could even be called "Grandpa's Survival Shack".

He consistently posts worthwhile threads on survival, chock-a-block full of real, useful information, in a clear, easy to read and understand fashion. It would be kinda nice to have them all in one place, and I think he deserves the recognition.

What do y'all think about that?

reply to post by blackrussian63


I used to see them for sale in hardware stores... or in camping and fishing supply places.. try eBay too... but if worse comes to worse... just get some tight weave heavy fabric (burlap/canvas) and make yourself one...

reply to post by GrandpaDave


Thanx...I want to give this a try, then pack it away in the memory bank.

reply to post by subject x


BTW that was part of the reason for the name change from DaddyBare to GrandpaDave...
you see I was thinking I could start off all my survival threads with "Grandpa's Survival Shack" you could type that into the search box and have the full list...

may not be the best plan but at least it's a plan right?

Originally posted by GrandpaDave
may not be the best plan but at least it's a plan right?

Any plan's better than no plan.
Like I always tell people, do something, even if it's wrong.

Always enjoy your threads. I don't often post in them, as you pretty much cover it all, and I'd just be saying "nice thread" over and again. Thanks for that.

On a side note, have you ever considered writing a book? You obviously have a lot of good, practical info to share, and it might even support you when you hit those "declining years", 20 or 30 years from now.

People probably have better more clear water than what i find here. Prefilter is always done here, but the bag is a great idea. I was actually looking at a .2 micron water bag yesterday, with built in filter but putting water thats not prefiltered into that would kill it quick.

Good stuff.

One suggestion might be to stick a small stiff bristle fingernail brush in so if it did get blocked pores you could inside out the thing and brush it off with a reverse flow to bring it back. just a thought.

FYI, Wally World has the grommets in the sewing section, almost bought some today, but decided to add an assortment of quilting and regular needles and thread colors instead. I got desperately low on variety of thread weights. They called the grommets rivets instead but are tarp weight. Am needing to make a custom size for under our tent, but will have a few left over for this filter bag. I also found new tea balls, which have been out of stock all summer, and some essential oils like tea tree for antiseptic use, and sandalwood for aromatics.
Like your water filter bag, GrandpaDaddyBare.

I've been known to instantly clog up my ceramic/carbon filters occasionally because any available water was particularly silty. First I started tieing paper coffee filters to the carbon filter's inlet but I went through them like crazy and they were hard to keep in the rugged environment of my back pack. I eventually started plumbing a paper fuel line filter in series with the main filter to avoid this but the canvas bag for a pre filter idea seems like it would have a much longer service life due to it's ruggedness and ability to be cleaned. I also like to carry items that have more than one use and a canvas bag is way more useful in the bush than a fuel line filter.
Thanks for the tip.

Agreed, but I always have just washed out my T shirt and used it as a pre filter, when needed.