Topic

Question about DIY Katadyn Gravity Filter


Forum Posting

A Membership is required to post in the forums. Login or become a member to post in the member forums!

Home Forums Gear Forums Make Your Own Gear Question about DIY Katadyn Gravity Filter

  • This topic is empty.
Viewing 15 posts - 1 through 15 (of 15 total)
  • Author
    Posts
  • #1255547
    Nate Powell
    Member

    @powell1nj

    Locale: North Carolina

    I recently stumbled across this post:

    http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=8994

    I thought I'd test out the concept by using an intact Nalgene bottle (i.e. not cutting the threads off or cutting a hole in the lid) instead of the stuff sac. The filter does fit in the Nalgene opening quite snugly as stated in the post but I'm getting zero flow through the filter when I flip the Nalgene upside-down and hold it above my clean reservoir. As far as I can tell this should work according to those plans. Any ideas why I'm getting no flow? Is it do to the fact that there isn't enough water pressure? It's almost as if there is some kind of vacuum happening. Apologies if the answer is obvious…I'm new to this stuff. Any thoughts are appreciated.

    #1576709
    Joe Clement
    BPL Member

    @skinewmexico

    Locale: Southwest

    I would think you had a vacuum problem. Air has to be able to get into the Nalgene for water to come out.

    #1576711
    Travis Leanna
    BPL Member

    @t-l

    Locale: Wisconsin
    #1576713
    Nate Powell
    Member

    @powell1nj

    Locale: North Carolina

    Thanks for the replies. I thought it might be a vacuum thing but was confused because it seems that you would have a similar situation with an air-tight drybag. I like your setup as well Travis, although I would personally want more capacity for my 'dirty' bag. Guess I'll have to try the real deal.

    #1576716
    Travis Leanna
    BPL Member

    @t-l

    Locale: Wisconsin

    FWIW, the collapsible Nalgene I'm using is 32 ounces. It can also work with the larger size, providing the opening in the nalgene is the same, which I think it is.

    #1577227
    Javan Dempsey
    Member

    @jdempsey

    Locale: The-Stateless-Society

    This just gave me an idea… ;)

    #1577231
    Travis Leanna
    BPL Member

    @t-l

    Locale: Wisconsin

    Uh oh. Javan's thinking again…. ; )

    #1577258
    Keith Selbo
    Spectator

    @herman666

    Locale: Northern Virginia

    The filter referred to in this thread as well as all the ones I found in the links in this thread have a design deficiency. They put the filter at the source so the water pressure is much lower than it would be with the filter at the other end of the hose. It might not be too bad with a fresh filter, but I think it could become problematic as the filter starts to clog over time.

    #1577263
    Travis Leanna
    BPL Member

    @t-l

    Locale: Wisconsin

    Very possibly true. I'm interested to see how this filter works over time, but so far, there's been close to 100 liters of water through this filter cartridge. I still get about 2 minutes per liter.

    #1577272
    Keith Selbo
    Spectator

    @herman666

    Locale: Northern Virginia

    I'm sure a lot depends on the porosity of the filter and what's in the water. I use a Sawyer 0.1 micron filter and it definitely benefits from the high head pressure.

    #1577273
    Travis Leanna
    BPL Member

    @t-l

    Locale: Wisconsin

    The Katadyn has a 0.3 micron rating, so it is a bit more porous than the Sawyer. I would imagine things would slow down a bit if the water was quite goopy. Ew.

    #1577279
    BlackHatGuy
    Spectator

    @sleeping

    Locale: The Cascades

    I've tried it nearly both ways, and have always had a much faster flow with more 'space' between the water and the filter. It's worked both ways, just better with the filter lower in the hose.

    As far as the filter not working at all in the Nalgene setup for Nathan, was it a brand new filter? If so, you probably just had to prime it. After that it'll probably work fine.

    #1577318
    Franco Darioli
    Spectator

    @franco

    Locale: Gauche, CU.

    With the Cantene (soft Nalgene) I start it with a squeeze and then it keeps going. I cannot get any flow out of the Lexan version. (that is with the filter inside the Nalgene) Sucking works but does not create a flow when you stop.
    Franco

    #1578149
    Rob Garren
    Member

    @vault415

    I had a problem similar to yours and my solution may help you…I made up the whole filter thingey, hacked everything together, filled it with water, and just a couple drips came out. You have to have a hose on the nipple of the filter (and sometimes give it a little suck to get it started).

    #1578153
    Travis Leanna
    BPL Member

    @t-l

    Locale: Wisconsin

    Rob,
    Yes, the hose made it work for me also. I didn't get much flow without it. Something to do with physics I think.

Viewing 15 posts - 1 through 15 (of 15 total)
  • You must be logged in to reply to this topic.
Forum Posting

A Membership is required to post in the forums. Login or become a member to post in the member forums!

Get the Newsletter

Get our free Handbook and Receive our weekly newsletter to see what's new at Backpacking Light!

Gear Research & Discovery Tools


Loading...