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Larry De La Briandais
(Hitech) - F

Locale: SF Bay Area
Daves not here... on 01/31/2014 08:48:29 MST Print View

But most everyone st work is my age (I'm 53). I understand the 30 something not getting it, but everyone else... At least someone here does! :^)

J R
(JRinGeorgia) - F
pre-filter on 01/31/2014 09:55:45 MST Print View

For a pre-filter I cut a circle of gold coffee filter and slipped it under the washer on the intake side of the filter. Effectively weightless.

Ryan Rourke
(Ryanjrourke) - F
Sawyer mini on 01/31/2014 13:03:12 MST Print View

I've found the best solution to be to use an adapter like the previous pic (couple bucks on amazon) that you connect to the output nipple via the included "straw" to a bottle. It's also the easiest way to fill up IMO. Since it is already attached after filling simply remove the dirty bag/bottle and squeeze back through some of the just filtered water. The "staw" fits so tightly that with a plastic bottle you can get really good pressure through it. I do this every time and have never had any slow down on the flow. It's definitely suffice for maintaining good flow on an extended trips. I still use the syringe when I get home but I honestly don't think I've ever needed to. P.S. The straw can be cut down significantly if you prefer. I just like to keep it long in case I need to use it as intended.Adapter

Edited by Ryanjrourke on 01/31/2014 13:21:25 MST.

Chad Poindexter
(Stick) - F

Locale: Wet & Humid Southeast....
Re: Sawyer Mini Backflushing on 01/31/2014 15:26:27 MST Print View

I haven't been using the Mini as long as I did the Squeeze, but I have used the Squeeze on a 7 day hike and it never needed any sort of backflush while on the trail. Depending on the expected water sources, I personally would be fine going the same length of time using the Mini without backflushing...

I always backflush the filter when I get back from any hike though. I fill a large glass with water and add some bleach to it, then backflush about 6 - 8 syringes through the filter. Then I let the filter sit for about an hour, and then I just flick the filter to remove most of the retained water. Then I put it up for storage.

Before heading out on any trip, I always fill a bladder with some water and "test" the filter before leaving. This lets me know that the filter is in working order before I head out, and it also flushes any of the bleach water back out of the filter. On the trail though, I still waste a little from the first filter before filling any water bottles.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Sawyer Mini Backflushing on 01/31/2014 15:37:14 MST Print View

The only problem with putting bleach in is

One problem with Squeeze (and mini?) is the pores can get clogged with mineral deposits

Bleach may exacerbate this

maybe better to just backflush with water

William F
(wkf) - F

Locale: PNW
syringe for irrigation/ first aid on 01/31/2014 16:14:33 MST Print View

I've never had to test it out, but wouldn't the size of the syringe be beneficial in terms of using for irrigation of open wounds? Add some iodine product to sterilize the water and then the syringe's size can create some serious force. I thought I read somewhere (maybe here maybe not) that one of the most important factors of preventing infection in open wounds is to irrigate the wound with high force/pressure. Can anyone with more first aid experience/knowledge chime in here as to the effectiveness of this idea? If I'm correct in my claim then I would argue the weight/bulk is worth it.

Samuel C. Farrington
(scfhome) - M

Locale: Chocorua NH, USA
Mini backflushing on 01/31/2014 18:10:43 MST Print View

Was going to wait till posting on MYOG about a mini pump filter using the Sawyer mini before bringing this up, but the time seems ripe.

Since I still cling to using bottles, Nalgene makes a soft-sided version of its standard wide-mouth quart bottle for cyclists (and it is lighter than the hard sided version). The top that comes with it can be stripped down to just a screw cap with a nipple projecting from the center of the top of the cap. After the bottle is filled with clean water pumped thru the Mini, the nippled cap can be used to connect the bottle via a short length of tube to the Mini outlet in order to backflush by squeezing the bottle. That creates a lot of pressure and a pint or so of water for backflushing, quite a bit more than from a small syringe. So no need to carry a syringe, just the nippled cap and the short length of tube. Regular Nalgene caps remain connected to the bottle for ordinary use. They don't thread perfectly, but well enough.

Haven't tried this yet on the trail, but the parts work and the concept seems OK.
Please share any flaws you see in the design.

Am wedded to the wide mouth bottles because I can carry tea or slurp in them and scrub them out easily when they start to get moldy. Nothing like a good chug of iced tea on a summit.

Edited by scfhome on 01/31/2014 18:11:27 MST.

Ryan Rourke
(Ryanjrourke) - F
Mini on 01/31/2014 18:14:23 MST Print View

Flushing a wound with iodine to prevent infection would absolutely be better than not doing it. I don't usually carry a bottle of iodine on me though. Personally I don't think the syringe is needed in the field. I am curious; what is everyone's method of filtering with the mini?

Ryan Rourke
(Ryanjrourke) - F
Mini on 01/31/2014 18:24:52 MST Print View

Samuel, the system you are thinking of using is what I do but with a smart water bottle (see my previous post). It works great for me. The straw that comes with the mini fits so well that it's hard to remove. I don't see any problems with it.

Samuel C. Farrington
(scfhome) - M

Locale: Chocorua NH, USA
Sawyer Mini backflushing on 01/31/2014 18:53:11 MST Print View

Ryan,
Thanks for the feedback.

Dale,
Am going back to Colorado this summer. Who's Dave?

cody yochum
(uclacody0908) - F

Locale: Nor Cal
Thanks Ryan on 02/01/2014 02:33:59 MST Print View

That's the setup I was picturing in my head.

Dean F.
(acrosome) - MLife

Locale: Back in the Front Range
Smaller syringes generate more force on 02/01/2014 17:43:13 MST Print View

Just FYI-

I keep seeing people saying that larger syringes generate more pressure. This is incorrect. The smaller syringes generate more pressure, but the tradeoff of course is less volume. One thumbpower over a large area is less pressure than one thumbpower over a smaller area.

When I'm unclogging a feeding tube I reach for the tiny tuberculin syringes.

[/pedantic rant]

Edited by acrosome on 02/01/2014 20:50:00 MST.

William F
(wkf) - F

Locale: PNW
Re: Smaller syringes generate more force on 02/01/2014 17:49:28 MST Print View

I'm no physicist but doesn't Force = Mass x Acceleration? In that case a bigger syringe most certainly produces more "force". Please correct me if I'm wrong.

I should clarify: the bigger syringe would have to have a bigger nozzle/opening of course.

Edited by wkf on 02/01/2014 17:52:05 MST.

John S.
(jshann) - F
Re: Re: Smaller syringes generate more force on 02/01/2014 17:56:42 MST Print View

Pressure is the ratio of force to the area over which that force is distributed.

Does tuberculin and larger volume syringes have same size exit hole? Maybe they do. In first aid I hear to use an 18 gauge needle to get a certain force for cleaning wounds.

Edited by jshann on 02/01/2014 20:49:15 MST.

William F
(wkf) - F

Locale: PNW
Re: Re: Re: Smaller syringes generate more force on 02/01/2014 18:02:33 MST Print View

But are we not confusing pressure and force here?

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Re: Re: Re: Smaller syringes generate more force on 02/01/2014 18:14:32 MST Print View

Pure physics vs practical use here I think.

You need to fill any void with water before you can produce any pressure.

Other than that, you need to be able to get your hands on the thing and push it up against the nipple on the filter to get a good seal. As annoying as it is, 1.2oz isn't going to break the bank. What does that come to in water weight? A mouthful?

I do like the Smartwater idea and out the cap in my kit.

Jeremy B.
(requiem) - F - M

Locale: Northern California
Re: Re: Re: Re: Smaller syringes generate more force on 02/01/2014 19:30:52 MST Print View

But are we not confusing pressure and force here?

Per Blaise Pascal: "If a vessel full of water, and closed on all sides, has two openings, one a hundred times as large as each other, and if each is supplied with a piston that fits exactly, then a man pushing the small piston will exert a force that will equal that of one hundred men pushing the large piston and will overcome that of ninety-nine men."

Pressure is, as John said, force acting over an area. Thus, PSI (pounds per square inch) represents a pressure value with "pounds" as the force component.

Addendum: for wound irrigation you want the area of the exit nozzle as small as possible in order to generate sufficient force to wash away debris.

Edited by requiem on 02/01/2014 19:46:54 MST.

Dean F.
(acrosome) - MLife

Locale: Back in the Front Range
Re: Re: Re: Re: Re: Smaller syringes generate more force on 02/01/2014 21:02:05 MST Print View

>>>Pure physics vs practical use here I think.

Yes, but in fact we ARE talking about pressure, for back flushing the filter. Not force.

FORCE is what you are applying to the plunger of the syringe. This is transmitted to the water via the plug at the end of the plunger. A smaller plug means more force per unit area, thus higher PRESSURE.

Ergo, smaller syringes generate higher pressures for a given force applied to the plunger. Likewise, there is a reason that bicycle pumps are long and skinny.

18g needles are used to irrigate because they will give high volumes of flow than e.g. a 27g needle. It has nothing to do with pressure.

Attach the tubing to a pressure transducer on one end and a syringe on the other. Place a standardized weight on the syringe plunger. Try this with both a 10cc and a 60cc syringe. Yes, the 10cc syringe will produce more pressure than the 60cc syringe. I'm not making this up, I swear.

Granted, yes, for practical matters you would want a certain minimal volume of water to back flush with, so there's a sweet spot there somewhere. A 0.5cc tuberculin syringe is not going to be practical for back flushing, no matter how high a pressure it generates.

Edited by acrosome on 02/01/2014 21:18:29 MST.

William F
(wkf) - F

Locale: PNW
Re: Re: Re: Re: Re: Re: Smaller syringes generate more force on 02/01/2014 21:16:43 MST Print View

Thanks for the clarification Jeremy and Dean. I was mistaken. I think I'll skip the experiment and take your word for it ;)

Jeremy B.
(requiem) - F - M

Locale: Northern California
Re: Re: Re: Re: Re: Re: Smaller syringes generate more force on 02/02/2014 00:29:03 MST Print View

18g needles are used to irrigate because they will give high volumes of flow than e.g. a 27g needle. It has nothing to do with pressure.

Isn't this really a trade-off though? E.g. 18g compared to 27g gives you sufficient volume, but go larger (e.g. the Sawyer syringe w/out a tip) and you don't get sufficient force? (At least, that was my limited experience.)

Edited by requiem on 02/02/2014 10:04:11 MST.