How many uses for the 2 litre plastic bottle come to mind?

-Bottle
-Funnel
-Cup/bowl
-Improvised waterfilter
-Make shift drip coffee machine. (Cut top part off, invert, add coffee filter, add coffee, poor in hot water. Use hot or warm water depending on the plastic type. Boiling water is bad)

Anything that can be improvised with thin bits of plastic:
- Cordage (thin stips)
- Templates
- Candle holder glass thingy.
- etc..

Dry goods, and of course, water storage. The 2 liter bottles are essentially waterproof containers that are small enough for daily usage. Anything that can get poured down a funnel, such as rice, coffee, or couscous, can be stored in the bottles.

EDIT: I forgot about the self watering and DIY container/tower garden projects that use 2 liter bottles. For someone with very limited space, it offers an alternative to conventional backyard vegetable gardens.

Trap for crawfish and minnows. Crawfish for food and the minnows for bait.

Can catch bugs as well (crickets, bees, wasps).

Flotation for packs, bundles, luggage, etc.

Sterilize water? (I've heard of successful experiments with clear plastic and UV from sunlight, but can't speak to their reliability.)

Wasp/hornet trap. (Very effective.)

Trail marker. (In wild country, man-made objects stick out like a sore thumb.)

Weight (water or sand) to add "spring" to tarp guy lines in gusty winds.

Two bottles with tops cut off, and insert one inside another. Makes a pretty good wide mouth container, used one for carrying bread baps in a rucksack for a week.

ZIllions. From the top of my head, and in addition to the above:

- compressed air tank (used 2 for DIY snuba device, can be used for improvising the energy source for the pneumatic instrument as well, as it holds up to 150 PSI);

- cut out 4 spoons;

- plants auto watering device;

- plants manual watering can;

- automatic animal feeder (grain/water);

- attach to a tree for a camp hand/face washing station;

- air/water pump (suck or blow);

- water distiller (put green leaves inside);

- plastic is hot-shrinking (apply heat over the plastic ties to tighten them);

- plastic of the bottle and of the cap can be melted to make seals, used as a glue, formed into hard plastic things, used to repair holes;

- the top screw with the cap can be used to seal plastic bags, make tarp attachment points, gather ends of fabric;

- cut out a grain/flour scoop;

- make long air/water pipes (cut ends, stack, shrink/melt joints);

- firestarter (water lens);

- camera "tripod" (1/4x20 screw in the cap, sand/water in the bottle);

- shoes (cut an entrance or flatten and add straps);

- sleeping bag warmer (feel with hot water, wrap in clothes, hug it);

- neck pillow;

- flashlight mount/stand/headband/diffuser;

- fishing bobber, fishing net floats;

- knee/elbow abrasion protection;

- safety glasses;

- smoke mask;

The "Practical Guide to Man-Powered Weapons and Ammunition" has a fairly extensive section on pneumatic launchers, and compressed air potato guns have an impressive array of blow off valve designs. While I'm not advocating armaments, the designs are common to many pneumatic machines.

" cut out a grain/flour scoop;" not just grain or flour. For years we have used scoops made from plastic containers to scoop up dirt an archeo or paleo excavations - nothing else works as well.

hot water bottle for keeping warm/storing heat.

Strips from the bottle can be used to open latches of some doors and windows. They can also be used to pick locks.
Just make sure that you have the right to open door, window or lock.

https://youtu.be/qFrvTq7FFXQ

qjs

Hygiene
Save Water Save Lives.
http://www.tippytap.org

UV Water Purification
SODIS
http://www.sodis.ch/methode/anwendung/index_EN

Paracord storage:

For a prepper: better than 2L Soda - 3L stackable Arrowhead water:

I LIKE those. Water storage is getting to be a hassle as we're up to 4 1/2 gallons per day. Stacking would make things that much easier.

My wife prefers her tea made with non-tap water, so we have been buying those 3L containers, and I have been using them for emergency water storage. Indeed, they are much better than 2L bottles.

Little critter trap:




String:

My hubby is addicted to Diet Coke, so we get a couple of 2L bottles every week, which I use for water storage. 3L sounds so much better, so I'm going to go looking for those. Thanks for the tip, guys~!

Very cool trap indeed! In the field, however, all you need to do is to cut the top off and bury the bottle with the bite into the ground vertically to the rim. Small critters cannot climb back up the smooth wall.

For the string procurement I'd prefer this "device":



But I'm always having some screws/nuts/washers and wood screws as well in my kits - too versatile not to.

Club soda addiction here. Cold, fizzy, and doesn't dissolve my enamel like regular colas.

On the subject of both 2 liter bottles and morale: 2 liter bottles are rated between 50 and 100 psi. I suggest water bottle rockets and alcohol vapor rockets (OK, more of a soda bottle mortar). I know it's childish, but for off-grid / grid-down family fun, it beats trying to teach the kids to play poker.

https://youtu.be/0qzOzjRJpaU
https://youtu.be/wuz0curb_hg

Making string from PET is interesting. What is the tensile strength of a typical (4mm or so) strand?

Probably not a good way to acquire a dynamic climbing rope - but for other uses....

It's polyester, which I found measured around 138 MPa for the thin film: http://www.shimadzu.com/an/industry/petrochemicalchemical/i206.html
That's the same as for cast iron, or bone.

Quite strong if made without nicks (takes practice). Most importantly it's hot-shrinkable. So you can make very tight joints with it (i.e. for the shelter building). See some proof (and another DIY tool guide) here (in Russian, but you can just turn off the sound for clarity, oh, he's made English subtitles already):


and here

Very interesting and potentially useful. But I do have a very elementary question - just what is an MPa? i rather imagine 138 MPa is stronger than 20 MPa, but probably not as good as 50,000 MPa. Cast iron and bone are not what I think of as having particularly notable tensile strength (at least the old bones with which I deal).

Heat shrinking sounds interesting. I wonder how many strands of this cordage I would need to plait together in order to get a rope that would meet UIAA specs?

Or this variety - the self resetting mouse trap:

It's all here: https://en.wikipedia.org/wiki/Pascal_(unit)

For the UIAA specs rope, I think, just get it's TS, divide by the 138, multiply by the cut surface of the sample tested above divided by your bottle strand's cut surface, and then multiply by 2 the resulting number of strands required just in case Should be a safe estimate, as you most likely will intertwine all the bands which makes the total TS better.

It's based on the Pascal -- a unit measuring force on a defined area, the equivalent of pounds per square inch (psi). In wasn't aware it was used to measure tensile strength, but upon reflection it makes sense. https://en.wikipedia.org/wiki/Ultimate_tensile_strength



+1. How much does it shrink? The stuff is everywhere. Contemplating the possible field uses now (cue sound of gears whirring and clanking in Babbage difference engine). Processing, processing ...

Not much f.w.i.w., but watch the second video, it shows exactly what you want - tools handles wrapping, looks promising. So far I used it just a couple of times to secure my DIY wet paper press ends - works as a disposable clamp better than paracord.

I've used those, based on a hint from this forum. They work. The plastic bottle seems more efficient than the beer can I used. In freezing climates, an inch or two of used motor oil at the bottom dispatches them quickly, and there is no smell. But live catch is also possible. I'm happy to report that I've never been that hungry.

Some years ago I was staying in a trailer working on a dig. Late at night I threw an apple core into a wastebasket. In the morning I found six mice had fallen into the basket in pursuit of the apple tidbit. Since I had plenty of pancake batter and tea, I released them into the wild.

I use them for water storage, but found that after about a year a couple bottles in the stash were completely empty and were shriveled up a bit.

The carpet wasn't wet when I discovered it so it must have occurred some time ago.

One I doubt anyone else will think of, supported by real life experience.

Carbide lamp.

Dump some carbide in the bottle, add a little water, poke a hole in the cap, screw it down, hold a lit match near the cap hole till the acetylene catches.

Caveat: do not add too much carbide and water at one time. If the acetylene production is too high, the bottle will pressurize and the lamp will become a flamethrower, or could detonate.

Fortunately, whenever I have had carbide in my greasy paws, I have also had a carbide lamp, much the better appliance for generating gas.

They are basically obsolete now, but I certainly appreciated the utility of a carbide lamp in caves and on many a night long search operation. After all, you have both heat, light, and flame for starting a fire, right in the palm of your hand. The lamp had a mechanism that regulated the flow of water into the carbide chamber, thus avoiding the over generation of acetylene, which will indeed produce a bomb, with often bad results.

I still have my lamps, but carbide is now a super hassle to obtain,so I light my way with electrics these days.

One more: http://www.instructables.com/id/Toilet-Roll-Dispenser/

For years I used something similar (wide mouth PET mayonnaise jar with lid) to protect the TP in an outhouse. I simply attached the container to the wall with drywall screws. Highly successful in fending off deer mice and moisture, both of which will gleefully reduce "the necessary" to confetti.