Make a Sling (weapon) Out of a Grocery Bag! (Plus Two Bonuses! "How Not to Use Scissors" & "Replace Bandaids With Sports Tape")




Introduction: Make a Sling (weapon) Out of a Grocery Bag! (Plus Two Bonuses! "How Not to Use Scissors" & "Replace Bandaids With Sports Tape")

(I came up with this idea during the Recycling-themed contest, but I hadn't the chance to instructable-ize it till now.)

You're stuck on a island with no sign of human habitation except some litter bobbing at the shoreline. You need to hunt the wildlife for food (or, if you're a vegetarian: there's a vicious critter (or coconut) stalking you, and you must kill it).
What do you do?

Construct a make-shift sling out of a plastic bag!

My goal was to create a reasonable sling out of a plastic bag using the simplest possible construction.
It's not all that accurate, nor powerful, but you're using less than half a plastic bag.
You're getting quite a lot out of this little scrap of trash.

- A plastic bag (grocery bags work well, but some of the classier, thick mil bags won't)
- Scissors (also useful for close-quarters combat with that vicious critter!)
- ... and some bandages + first aid cream (see step 5)

General construction:
2 x ropes from twisted strips of plastic
1 x cradle from folded rectangle
1 x finger loop

Project takes about 10-20 minutes, possibly less.

Don't poke anyone's eye out, don't strangle puppies with the sling. General safety rules apply, but by and large, this sling is a rather tame weapon. (I think you need to be more conscientious that your left-over plastic isn't a choke hazard than over projectile injury.)
Honestly, I'm more likely to use this to lob crumpled paper at my friends than anything else, so I'm blatantly ignoring the "don't shoot people" rule.

Step 1: Snip, Snip

Get a bag.

Flatten it out so that the layers are neatly folded.

Across both sides, in line with the handles, cut two loops of plastic bag.
- With most grocery bags, the plastic is folded accordion-style and sealed at the handles
- If you trim about 1.5inches off the edge, you should end up with a continuous loop of plastic (with little flaps at what used to be the top of the handle and the bottom of the bag)

It might help to mark where to cut (I can't cut in a straight line unless I have guides)

Now, cut off one set of flaps so that you no longer have a loop, but a single strip of plastic.

Step 2: Twist!

Tie a knot at each end of your plastic strips.

Start twisting one strip into a rope.
- You may find it helpful to use some anchoring device.
- Make sure you twist the entirety of the strip in one direction

Since you are working with a fairly long strip of plastic:
- The end you are twisting will be more compact
- Sections of the plastic may remain rather "fat"

Just pinch a stubborn section between your fingers and simply roll back and forth

Step 3: Sort-of-but-not-really Untwist!

Hopefully the plastic is now reasonably circular in cross section.

Grab both ends in the same hand while anchoring the middle. (The accompanying photo was taken with my chin, so don't whine about it being blurry.)


Your rope should do some bizarre acrobatics and end up with both sides winding around each other.
- Tie a knot to secure the loose ends!

Chances are good that your doubled-up rope is rather loosely twisted.
- Continue twisting the plastic to tighten the strands a bit

Now go back to step 2 and repeat the process with your second strip of plastic.

Step 4: Start on the Cradle

You now have two twisty ropes of plastic. Put them aside.

Grab the portion of the plastic bag that you haven't yet used (you didn't throw it out already, did you?)

Cut a rectangle about 5inches wide and 6inches long.
- The "5inches wide" is the more important measurement--you'll be trimming off excess length later

Don't cut yourself.

Step 5: A Brief Digression on First-aid

Since I had my camera out, I figured I'd document the bandaging process while I was at it.

I've stopped buying commercial bandaids and have switched over to sports tape.

Using a bit of tissue with antibiotic first-aid cream, I covered the cut.

I tore off 3inches of sports tape and divided it into two strips

Tape. Tape. Fixed!

I've found that sports tape is pretty useful for bandaging fingertips: using a 1-2inch strip across the top of the finger and wrapping another 3 inches of tape around makes for a very secure binding.

Step 6: We Now Return to Your Regularly Scheduled Broadcast: the Cradle

Take your rectangle of plastic (you didn't lose it in the shuffle to bandage your bleeding finger, did you?)
- Fold it in half
- And again

Pinch together one end and thread through the loop of one of your ropes
- You will probably wish to use the continuous loop (i.e. "not the one with knots")
- Tie the sling
- Repeat with other end, making sure you have about 3-4inches between the knots
- Trim off excess

Step 7: Finger Loop & Finish!

Cut a little rectangle of plastic approximately 1"x4"

Fold and twist it a bit and tie it into a small loop.

Now: loop the new little loop onto the knotted-end of your rope-loop and loop the little loop loosely over the rope.

Just... get it so that the little loop is secured one side of the sling, and pull the sling through the loop to create a larger area to accommodate your finger.
- This convoluted atrocity will be where the sling remains fastened to your hand. The other end will be the one released when you fling things.

Go ahead and hold your sling.
- Make adjustments if needed to get the cradle to sit level

Oh, hey, look: you've got more than half of your plastic bag remaining! Make more slings!
- This might be a very poor decision if you have siblings of similar age, or of exceptional belligerence

And to show that this sling can fling things:

Now, if only I had enough space to see if I could aim this sling... (And no, I wasn't aiming for the tupperware, I was aiming for the wall. I hit it, too.)

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    12 years ago on Step 6

    i am having trouble with step 6 can u give more detail????pls


    Reply 9 years ago on Introduction

    Basically, If I understand this correctly, You must take a roughly 5"x6" piece and fold it in half twice length-wise and then tie an end to each rope like thing.


    10 years ago on Introduction

    a easier way to kill a animal is to,stick the bag on its head, you have more of a chanch of hitting it! :)


    11 years ago on Introduction

    I wrote an instructable on how to make a 7 part braided rope from plastic bags, it might make a slightly more durable sling. Also I thought using the techniques posted elsewhere here on instructables which fuse many layers of plastic bags together using a clothing iron might make for an interesting idea for a cup/pouch for the rock.

    But nice Instructable!  It got me thinking.


    Reply 12 years ago on Introduction

    SPAM!!!!!! Ps in your comment you forgot to say tell your friends about it (=


    Reply 12 years ago on Introduction

    Sorry. I didn't mean it as spam, I was just telling people other ways to make these!


    Reply 12 years ago on Introduction

    I was joking didnt you read the small print?


    12 years ago on Step 5

    You stole my idea for an instructables no no no no NO!

    bubba j
    bubba j

    Reply 12 years ago on Introduction

    na i propboply would stab it with a pice of sheet metal from the wreak


    13 years ago on Introduction

    i alaws draw a smile face on my band-aids.nice instructable i'll have to try it.


    13 years ago on Introduction

    can i make a sling from jeans pants i meant for the pouch.whill it stay there or tear in half.


    13 years ago on Introduction

    HOLY SNAP!!! I made this, like, quick, went outside and threw rocks into my coldisac(sp?) I hit a tree in someones backyard on the OTHER end of the coldisac. this is great. Water proof too