I started this project a few days ago because I was bored and wanted something to do with my hands while I listened to podcasts. After three days I've gone through every bag in the house and have about 150' of cordage.
I told a friend about this project and he asked me to post an instructable so he could try it out with his scout troop. So here goes.
This is my first post. Please be nice to me.
Step 1: What You Need
-Two hands (preferably both yours)
-Messy desk (optional)
Step 2: Prep Your Bag
Cut the fused bottom and the handles off the bag and then cut the rest of the bag into strips approximatly 1" to 1-1/2" wide. You can measure and mark your cuts if you want a more uniform cord, but I just eyeballed it. Smaller strips will make for thinner cord.
When this is done you will have a handful of plastic circles.
You can prep several bags at once or do it as you go along. I've found myself doing both.
Step 3: Twisting the Cord
Take one of your plastic circles and grip it slightly off center with both hands. Twist it in opposite directions, clockwise with your right hand and counter clockwise with your left. Eventually the strand will be twisted tight enough that it kinks in the middle and twists up on itself. Congratulations, you just made some cord.
Keep going, twisting both ends and letting them naturally twist together. If you notice one side kinking on its own then it's wrapped too tight. Focus on the other side for a bit.
Occasionally I will pinch the top of my new cord and twist the section I just made a little tighter to make the strands lay together a little nicer.
Step 4: Adding More Material
All you're doing here is tying a larks head knot.
Take the end of your strand that is almost finished and poke a finger through it so you once again have a loop.
Take a new plastic circle and feed one end through that loop. Feed the other end of the circle through the first. Gently pull the knot you've made tight, careful not to rip your circle, and then continue twisting your strands into cord. The knot will make a bulge in the cord but that's not really a big deal.
Step 5: Different Colors
Step 6: Keep Going or Finish
Keep twisting your cord together until you've either:
Run out of bags,
Or your hands hurt.
Finish up by tying a knot in the end of your cord and cutting the excess off. I was thinking about trying to fuse the ends of mine with a lighter or hot knife, but HDPE plastic is a petroleum product and is very flammable. I've used plastic bags as tinder in a pinch. Be very careful if you try this.
There you go. You've just turned trash into something useful again.
So what would I use this for? Anything I would use cord or twine for. I could lash things together, I could wrap several strands to make a rope, I could use it to tie up garden vines, make a macrame strap for my ukulele or pouch for my water bottle, wrap an axe or hammer handle, I could probably weave it into a rug or a bag... anything really.