Improved Water Scoop: Design Phase

[Ben H.]

Background 

I had an idea for an improved water scoop.  I thought I could hack my way through CAD and get a part 3D printed and show it to people on here if they want to make it themselves.  I ran in to some snags, so I thought I would see if the learned people on here knew of good solutions.

Idea

I always have problems getting water from trickling sources I often find in the back-country.  Bottles don’t sit flat on the ground to allow water to flow in.  Bags (like a cut Platypus) are awkward to hold and difficult to hold open to allow the water in.  My idea was to have a small plastic frame that would hold a platypus like bag open (kind of like those leaf raking bag holders they used to sell on infomercials).  It would be flat on one side to allow you to hold it close to the ground.  The other side would have a small handle to hold it with.  Perpendicular to those two sides would be a pour spout with a strainer to allow transfer the water to a water bottle of other container.  The strainer would act like a prefilter.

Problems

The big obstacle I have come across is that apparently 3D printed plastics are never food grade.  The biggest issue is the small cracks and crevices are a heaven for mold and bacteria.  Should I give up on 3D printing this thing?  Or should I print it up and seal it with an epoxy?  If you think it is still a good idea to print it, what plastic and what epoxy should I use?  Are there alternatives to 3D printing to get a couple of these made?  If someone where making a million a thermal molded plastic would work great.  It would be too expensive to make just a couple I am guessing.

Secondly, if I was able to get the frame made, does anyone have a good idea on how to attach the water bag?  Is there an easy DIY technique to thermal seal two plastics together?  I am thinking maybe a soldering iron or something similar.  Is there a glue that would work well?  I guess I could put a lip on the frame and hold the bag on with a rubber band, but that doesn’t sound like it would up well to the weight of the water in the bag.

 

So… that is my idea I would love to hear your thoughts on it.

[Roger Caffin]

You could try an A4 (or Letter) sized plastic bag from the fruit section of your local supermarket. Just hold it in place with your hands. Yeah, they might get wet.

Not wishing to be rude, but all these ideas for gimmicky things are really what BPL is AGAINST. We don’t need more complex things in our packs; we need less things. KISS.

Cheers

[David Thomas]

Dumpster dive at the recycling center in the #2 HDPE bin and imagine how different containers could be cut down into a scoop.  A gallon milk jug weighs almost nothing to start with, comes with a handle and you’d be cutting away* 70-80% of it.  You could leave a large, flat bottom with just enough sides to stiffen it up.  Then, after letting chunks settle for a few seconds, decant the water through the factory spout into your water bottle, repeating as necessary.  Or just leave a corner if your streams are narrow (versus wide and shallow).  They’re not as common, but the 1/2-gallon HDPE milk and orange-juice jugs might beh big enough and while taking up less space.

For containers like motor oil and detergent, I run them through the dishwasher to completely remove any residue prior to using them for water or food.  Unlike some plastics, HDPE goes through a dishwasher just fine.  That opens up other options of sizing and stiffnesses (generally they are thicker than the milk jugs).

* kitchen or shop shears cut these containers very easily, with good control, and are far safer than a razor knife.  Use a Sharpie to mark your cut line and the result will look more polished.

[Gary Dunckel]

Roger, that was a bit harsh. BPL ISN’T all about minimizing gimmicky things. But it IS about being creative in solving problems that one has in the backcountry, or coming up with things that make life easier in camp (or while hiking). I know that I was overjoyed to get my base weight down to a happy level. Then when I got down even further, I was able to rationalize bringing some MYOG items that solved some chronic peeves of mine. The act of dropping a few pounds allows one to get creative (not gimmicky) and add a few ounces back. But I suppose one man’s creativity is another man’s gimmickry.

Anyway, I think David is onto some sort of solution here…

[Franco Darioli]

Some stuff sacks , like these

have a stiff neck . They are in silnylon so light enough.

I use them to hold  bits and pieces.

[BlackHatGuy]

What a boring little pedant you are at times Roger. Silly me, I always thought BPL was about encouragement, thinking outside the box and ingenuity. But then again, I’m not a ‘scientist’….

Ben, I like using a cut-down platy for a water-filling vessel. But instead of trying to put the ‘wide’ portion of the platy in the water and hold that open, when using shallow, running sources, I hold one of the bonded sides and press the other into the water. This will naturally force the platy open and is easier to hold.

A small, plastic finger loop that sort of clips onto the bag might be handy though, if you looked in that direction.

[Ben H.]

Roger, sorry if you think this is gimmicky, but I am certainly not suggesting adding things to someones pack.  Many people who carry a Steripen (and other water treatment techniques) carry a dirty water vessel that they use scoop water up with.  I am glad as a clam that you haven’t had any difficulty scooping up water from the places you hike, but that is not true for me where I hike.  I thought of a simple device that I think could make this much easier.  It would replace the existing dirty water bag many people already carry for minimal additional weight.  How much time do we spend in the back country looking for and getting water?  Why would you not want to make that easier?  But you know what I am not here trying to sell people on a gimmicky product.  I am trying to develop something I would find useful and asking people with knowledge for help as is a standard part of the DIY forum.  I don’t really care if you would use it or not.

[JCH]

Ben – I like where you are going…keep it up. Doug’s “finger loop” also sounds intriguing. Most of us would not hesitate to add a 10 g dohickie to our packs if it made life easier.

And pay no attention to Roger. He’s been cutivating rather the reputation lately for poo-pooing other people’s ideas. He rather fancies his own though it seems.  Hell, he even seems comfortable schlepping a piece of plywood around to set his stove on :)

[Roger Caffin]

OK, maybe I was a bit harsh – sorry. (Btw – criticisms cheerfully accepted – feel free.)

One of the core tenets of BPL is reducing pack weight by leaving excess and unnecessary items behind. A 3D printed scoop is always going to be heavier than a simple plastic bag, and heavier too than a cut-down PET bottle (aka milk bottle) – not to mention more expensive. Both plas bags and PET bottles will have a much better surface for water as well.

Yes, I have used a cut-down PET bottle for collecting water, as an experiment, and I have used a simple plastic bag as well. Imho, the plas bag worked better than the PET bottle because it was able to get right down onto the rock. I supplemented the plas bag by getting some long leaves and laying them over the edge of the plas bag to help guide the water into the bag rather than under the edge. Yeah, water was a bit short that day.

As for the bit of plywood – you try sitting a stove with legs on the snow and see what happens! At 22 g it works better than anything else I have found for that. Soft little bits of plastic don’t work too well with the heat.

Hum – I must try replacing the 3-ply with light Al sheet. Trouble is, the Al sheet will conduct heat through to the snow underneath and start it melting …

Hth
Cheers

[Matthew / BPL]

Ben, Check out Protolabs. They fill an interesting niche when ramping up manufacturing and in prototyping phases. My understanding is that they 3D print, then machine (if needed) then do some relatively inexpensive casting techniques. I believe they try to fill a niche between one-off prototyping and full manufacturing.

Anyhow, it occurs to me that they might be able to 3D print then machine smooth, thereby addressing your concern about food safe plastic.

Another thought: we are we concerned about food safe materials if the water will be filtered?

That said, I’ve not had any problems scooping from shallow, slow creeks. I use the cut-off bottom of a 16 ounce Sawyer bladder. Maybe I’ve just gotten lucky or maybe there is something about the material (it seems harder and more crisp than what Platy uses).

[Jon Fong / Flat Cat Gear]

Go old school: origami.  Super light weight

To fit into the UL environment,use your waterproof topo for the media

[Matthew / BPL]

that is an excellent idea!

[Allen C]

This should do the trick!

[Ralph Burgess]

There are plenty of small plastic drink bottles with square cross section in the supermarket.   They usually contain something like an organic gluten-free hand-blended chia carrot & kale smoothie for $4.95.   Buy one, pour the contents down the toilet, and cut across it so that you have a little cup with flat sides.  The flat sides allow you to scoop water out of the shallowest depression, or you can stand it under a dripping source.   But for a dripping source you can just use whatever cup or pot you use for cooking anyway.

I only take a scoop like this when I’m in the desert and I might need to access shallow potholes.   Under any other circumstances, so long as your water bottles are wide mouth I don’t know why you need a scoop.

[Cameron M]

While I sometimes encounter small trickling streams, I largely try to avoid them as I generally don’t trust them as much as ones that flow more. If I really needed to draw water from one I imagine that I would just use one of my surplus ziplock bags to collect what I needed.

 

[Ben H.]

Thanks Mathew for the link to Protolabs.  It is close to what I expected.  Around $1500 minimum to get into injection molding.  Probably reasonable if I wanted to sell a couple thousand of these… but I do not.  Even polishing 3D printed plastic does not make it food safe.  It might be something I will try anyway.  It would mean you could not treat the water in the bag.  You would have to pour it into your clean reservoir to treat.  For my Steripen that means a wide mouth vessel… something I was trying to get away from.

Cast Urethane, seems to be another option.  From what I have read you can create food safe products, but it is hard to find companies having gone through the process to certify that they are food safe.  Trying to figure out what certification is necessary and what is only important from a legal perspective.

[Ben H.]

Also, wanted to add: thanks all for the alternate ideas.  If this project does not happen I’ll probably explore these alternate as an actual solution.

[Monty Montana]

Hi Ben.  I’ve always been using a Tyvek envelope – stuff occasionally shows up in the mail in one of these, and I’m one of those rare individuals who still uses the mail – and it works wonderfully well for this application in that it’s waterproof and in addition folds flat when not in use.

So, to turn your envelope into a scoop cut a diagonal 2 or 3 inches from one bottom corner to the other side.  To use, hold the short side and press the long side down into the rivulet of water, which will cause it to flatten as much as you want, then, voila, scoop.  Then I do the same to another envelope, except with this one I cut a bit of the corner off on the long side to make a funnel, which allows me to guide drips into my water bottle.

Don’t know what the food grade value is for Tyvek, but the water is in contact for such a short period it’s pretty much nil or at least negligible.

Hope this helps; happy trails!

[Craig B]

Hi, Ben,

I think a lot of the other ideas presented here would work just as well, but if you really want to go with a design of your own, a coating on a 3D printed part would probably work.  I think you can get a food grade RTV (silicone), which should stick reasonably well to a print (You might need to rough the surface a bit).  Check out 3D Hubs.  It’s a network of people who will print you something on their printer, and they are all generally much cheaper than commercial prototyping houses.  You’ll mostly be stuck with fused deposition modeling (FDM) printers, as those are the cheap ones that sell for a couple grand, but they make good parts if you don’t care about super high resolution (which you probably don’t for this).  PLA is a common resin for these, is compostable, and the stiffest material you can have printed.  You might even be able to find a food-grade version, as this is what they make the compostable plastic utensils from.  You can probably find someone to print your part for around $100, depending on the volume of resin used.  Hope that helps.

Craig

[Adam Kilpatrick]

I design and 3D print parts for work sometimes, mostly with PLA. I haven’t tried adding coatings to it yet, though its not a bad idea. Another idea I’ve had but haven’t tried yet, its to use cuben fibre as a shell material to a 3D printed part. 3D printers, at least the ones in most people and organisations price ranges, have a minimum thickness of part you can print. It could be 0.2mm, depends on the circumstances (really does…). This doesn’t sound like much but can build up to a lot of weight. But instead making a “space frame” for the object in question instead, and carefully glueing cut to shape pieces of cuben fibre over could work. One could potentially also then add epoxy to one or both sides of the cuben as a stiffener or filler if required. Or using expanding foam. Or other things. Just depends on what you are trying to achieve.

So, could you 3D print a PLA space frame, then, use carefully cut and glued cuben to it, as your scoop? If you need a folding scoop, this would be achievable as the cuben would happily flex around the fold.

If you send me through .stl files (and your settings for layers, fill % etc) I’m happy to have a go at printing at my end on PLA on our printer. Easier to give feedback if I can see a printed prototype (its not always obvious what design flaws could be until you print it out…).

:-)

[Gary Dunckel]

OK, good buddy Roger, so you don’t really like gimmicks? Boy, do I have one here for you. Here are the components, with a total weight of 18.4 gm (.65 oz).

What is it, you ask? Well, we have a square piece of titanium foil, a matching piece of .125″ evo foam, and a folded up piece of a cuben gimmick thingy. The original purpose was to organize my nighttime essentials next to me in the tent, so that nothing would try to escape.

The cuben tray is reinforced with titanium rods along the top and in the corners to allow it to keep its shape. I’ve also waterproofed it with seam grip. Since it can be folded up, here’s one thing it can do (in the interest in of being true to the thread). It can easily direct water from a small trickle into my Platypus bottle.

Being waterproof, it can serve as a water bath for a fuel canister (with the foil and foam removed of course), and it serves as a tidy place to set my Jetboil pot to keep it out of the dirt when I want to use the BRS-3000T stove with another cup or pot (I keep the foam and ti foil in it for this use, to prevent the hot JB pot from harming the cuben).

The foam and titanium foil by themselves create a great coaster to insulate the bottom of my coffee cup (which has its own cozy, but the bottom isn’t insulated). A common way that I use this is if I have a bear canister, which serves as a small table with a a flat surface. The titanium foil insulates things from the cold ground or canister, and the foam on top of that helps insulate the bottom of the cup, keeping the coffee warm much longer.

I usually hike with a common ball cap. I always try to have one that is light gray or tan, to help reflect our intense Colorado sunlight. I am also a big U. of North Carolina Tarheels fan, so here’s my favorite cap.

Here’s an idea I got from Mike Clelland!, which allows me to leave the headlamp strap and little cuben stuff sack at home and save a bit of weight (17.4 gm or .61 oz to be exact). The Black Diamond Iota lamp fits nicely on the back strap of this particular cap. This sweet little headlamp without the strap weighs just 1.4 oz.

Formerly, I simply used a ball cap to hold my nighttime essentials, but occasionally something would escape through the back of the cap and end up under my mattress or someplace. I still like to have my headlamp with me in the tent, so here’s what I do now.

I can still fit a can of pepper spray inside the ball cap if I’m sleeping in griz country, but there’s no need for that in Colorado.

I’ve found several other uses for this cuben tray. For example, a temporary place to store small items so that they don’t get lost, or a little plate/bowl for snacks. And if you usually hike with your chihuahua or your cat, you can give them a drink of water from this little bowl.

I normally just carry the components in one of my pack’s side or front pockets. If I want to secure them in a pint size freezer bag, I just wait until dinner the first night and do a David Thomas ‘dumpster dive’ to re-purpose the bag that the meal was packaged in.

So, Roger, this little cuben thing is multiple-use, it adds minimal weight to my pack (1.0 gm), and in my humble opinion, it’s a rather useful and creative gimmick. Win, win, win. At the very least, the time it took me to make it kept me off the streets and out of the bars, helping America be safe(r) again.

[DAN-Y/FANCEE FEEST]

Stainless steel (.002)envelope stores flat and can be used to boil water in it also. Use it to scoop shallow pools of water. Might be of interest to someone. It was my creation for backpackers that liked using wood as their goto fuel. 3d printing is fascinating, thanks for all the info :-)

[Roger Caffin]

Hi Gary & Dan

Amazing stuff! The mind boggles at the creativity! Very BPL.

I have to ask Dan where does the SS bag come from? Heat treatment gear?
And how much do the forceps weigh? :) (My small ones weigh 20.6 g.)

Cheers

[Jan Rezac]

To collect water from small trickling sources, I use a following gimmick: a piece of silicone tubing (piece of ca. 15 in, diameter 1/2 in, thin wall). In the smallest springs and streams, there may not be any basin where a scoop can be used (and these are my preferred sources: flowing, cold water that just springs from the ground is likely to be safe, and I may not treat it at all). It weights 0.6 oz, but it can be considered a shared item – once the flow is diverted to the tube, the whole group can fill their bottles easily.

[DAN-Y/FANCEE FEEST]

I have to ask Dan where does the SS bag come from?

 

The location is listed under the video at youtube site

zellph
Published on May 6, 2010

Stainless steel Slimline flat pot for campfires. Easy for backpackers and campers to compress for easy storage. Available at http://www.mcmaster.com/#heat-treatin…

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