Very Strong Shopping Bag Rope - No Tools Needed

I started thinking about rope recently after Mr. Balleng posted his rope making instructable.   I also remembered this old instructable in which they made a rope from shopping bags using a giant twisting device made out of bicycle parts.  Then I thought, why do you need to twist it?  I think twisting makes sense if you are using a very fibrous material so the fibers can kind of grab together and get intermeshed.  But plastic shopping bags aren't really fibrous, so maybe you don't need to bother with the twisting.

So I came up with this way to make a very strong rope.  The cool thing about it is you don't need *any* tools to make it.

Step 1: Materials

plastic grocery bags - lots of them.  You can get a lot by asking on freecycle.org.  I posted a message asking for them and got enough plastic bags to make 150 feet of rope!

Figure on approximately 2 bags per foot of rope

optional: scissors

Step 2: Flatten the Bags

Straighten out the bag and flatten it out as indicated in the photos.

Step 3: Tear Through the Middle

As promised, no tools needed.....

You can use your fingers and tear them vertically from bottom to top very easily as demonstrated in the video.

Step 4: Optional Tool: Scissors

okay, if you have some scissors around, you can just cut them en masse

Step 5: Make Strands

Chain each half section of bag together with the next as shown in the photos.

Tear a tiny hole in the side near the bottom seam.
Thread the handle of another section through the hole you just made.
Thread the body of the other section through it's own handle you just passed through.
Pull it tight.

Repeat until you have about 5 or 6 half bags connected together into a strand about 6 feet long.

Make at least 2 of these strands to get started. It helps if they are contrasting colors, but not especially necessary.

Step 6: Start Braiding

Take the two starter strands and wrap them around something solid.   I'm using a c-clamp clamped to the edge of a table.  You can use your feet though, to hold it still while you braid.

Offset their knots so that while you are braiding, the knots are not lining up together all at once (which would resulting in a much nappier rope).

Step 7: Braid

Much like bubble wrap - this is a kind of pleasant activity you can do while watching a movie or something.

You have four strands.  
The pattern is
   Right two strands:
       Right over left
   Left two strands:
       Right over left
   Middle two strands
       Left over right
Repeat

Step 8: Splice in New Strands

As you are braiding and you start to run out of length on a strand, you can just extend it the same way you made the strings in step 3.

Try to keep your strand length to a maximum of 6 half bags or so.  Otherwise they start getting tangled and you spend a lot of time untangling the free ends.

Step 9: How Strong Is It?

It is very very strong.  However I have yet to devise a test that will strain it to the point of breaking it.  

Will a single strand of it support my weight?   I *think* so, but I'm still working on a test for that that isn't too scary.
If I braided two or three strands of it together into a big fat rope would that hold my weight.  I'm certain it would.  You could probably tow a car with it.  
Would I stake my life on its strength?   Um... no.  
Would I use to to go mountain climbing.  No way.
Would I use it to save myself if I had nothing else to work with?  Absolutely.  Yes.  it is really strong.

I'm thinking of making something out it...  Still playing around with some ideas.

Step 10: Some Cautionary Statements

Many people have pointed out in the comments that grocery bags will degrade in sunlight over time.    

I did think about that and pondered possible solutions - however all my ideas were expensive and laborious.  E.g., what if you painted the rope with some kind of outdoor plastic paint.   Or, what if I wrapped the rope in some other material that was not quickly degraded.   

So, take that under advisement.  This rope shouldn't be left out exposed to sunlight.  It should be put away somewhere shady after use.

Maybe I will do some experiments and report back on just how long the rope lasts under various conditions.  My todo list is already pretty booked though.  but maybe I'll get to it.

Also, please use common sense.  This was just sort of an experiment.  There are no guarantees as to how strong this rope really is and whether it should be relied upon for any serious lifting or dangerous applications.    Like a chain, a rope is only as strong as it's weakest section.

Comments

[SwordSlash300]

That is awesome! Now i can use all my grocery bags and I want to try and test its strength! Awesome idea! :)

[Basement_Craftsman]

I did this in a grocery store, when I was bored out of my mind. You sure brought it to a higher level. Nice 'ible

[Captain443]

WTG --- Get Job.... For your weight testing I might suggest taking a 3 ft piece of threaded rod bending it over to from an eye on one end and then get a nut, a washer, and a piece of some material (Block of wood) big enough to hold everyday weights on the threaded rod... Then hang the rope from whatever you want, attach the eye hook and build up the weight's until it breaks.... Just a thought ... Good Luck....

[foobear]

Thank you for the positive feedback! And yes, I do need to get a job - heehee

[Captain443]

LOL...I am sorry I dont know where the word "GET" came from...
It was supposed to be "Great"....
Like in WTG --- Great Job....

Again I thought it was a Job Well Done and I am sorry for the type-o

Good Luck I hope the weight testting works out for you....

[bob3030]

I've always liked recycle/reuse projects. Thanks for posting.

[foobear]

thank you for the positive feedback

[gerflash]

Wow! Good idea! Now I know what to do with that 5 year collection of poly bags that I just couldn't throw out! And yes, got to watch out for excess exposure to sunlite.

[foobear]

glad to help

[kyluddy]

This is a great idea! You did a great job and it's a perfect idea! Its a great way to recycle and it's just plain awesome. Really good job.

[foobear]

Thank you. Your comment is 100% positive and I really appreciate that.

[JohannaW10]

Thanks for the tutorial, I think using 3 or 4 already braided stands twined or braided together would be very strong and sunlight wouldn't be a problem for a long long time. It takes awhile for plastic tarp to deteriorate after years in the sun, so using this plastic bag rope should last longer then you'd probably need it for anyways.
I'm going to make a hammock or a tree net with it.

[murat.tamgili]

great idea recycle has no limits however thoughts on durability it s still really useful idea thanks for ible

[KendraH10]

This was pretty simple :)

[joceyrichard]

the standard plastic bag can hold up to 17 pounds. So the robe is pretty strong! I am using my rope to make a hammock. I just made a swing out of it and it works just fine. But I made sure to put it in the shade.

[foobear]

That's cool. I didn't know that about the 17 pounds strength. Please post a photo of your finished hammock when you finish it!

[joceyrichard]

the standard plastic bag can hold up to 17 pounds. So the robe is pretty strong! I am using my rope to make a hammock. I just made a swing out of it and it works just fine. But I made sure to put it in the shade.

[joceyrichard]

the standard plastic bag can hold up to 17 pounds. So the robe is pretty strong! I am using my rope to make a hammock. I just made a swing out of it and it works just fine. But I made sure to put it in the shade.

[leon0862]

Awesome work. Had a tiny bit trouble following the braiding steps (Mental/Visually) but I completely understand it. As for the whole "don't leave in the SUN" problem, out of most I have to say it would make great rope for water. Since Natural/Classic rope made of technically dead plants from their fiber, this is at least a cheaper and recyclable improv-ment.

[leon0862]

As for test wise: Try it on other set of test first before you put your own self at risk.

Challenge not just a few but every condition you can. I.E.: Weather, Temp, Moisture, Reliability, Chemical Reactions (In case of some Chems. that can/will dissolve it), Stress, and Durability,(I know some of you will say aren't the two the same but I mean by strength on how well it can just be pull straight out, and How well it will handle Gimmicks like multiple pulleys and puling over corners.)