Picture of Lock a door using paracord
This instructable will show you how to temporarily lock a standard, internal door from inside or out, using a minimum of 4 feet of cord (and a padlock if you are locking the door from the outside) although for ease of use, a large paper clip and some sort of hook and a keyring can be added.

Step 1: Attach the cord to the door handle

Picture of Attach the cord to the door handle
 Although this may seem simple enough, this is the hardest part of the project as the knot tends to slide along the handle to the pivot end when someone tries to turn the handle.

First, cut a length of cord aproximately 12"long and fold it in half, then tie a knot at the folded end, leaving a loop just big enough to fit the end of the door handle through. Place this over the handle with the knot at the bottom, then pull the two loose ends up over the little lumps on the end of the handle and tuck them under the top of the loop. put them back through the loop and pull upwards then the cord should be attached to the end of the handle. 

If you are using a hook and a ring (inside lock only), tie the ring to the two bits of cord hanging off the top, otherwise, just tie a big knot that you can attach the second piece of cord (from the top of the door to)
cmcclellan2 years ago
What if your doorknob is round? Anyway to lock that with paracord? Ideas?
The Skinnerz (author)  cmcclellan2 years ago
You may be able to tie a loop around the handle, then tightly wrap a few extra turns around it in a direction such that any attempt to turn the handle will just try to pull it tighter. Adding a layer of electrical tape or similar around the handle first would probably help it grip better.
daltonjcw4 years ago

Open sesame!

Like Onikus said, Wire. Steel cable. Good Stuff.

Good 'ible, Though
tabgilbert5 years ago
Good travel information.  Thanks.
onikus5 years ago
 note to self "find knife" 

sorry had to, i like the concept it's original I would bet this would work pretty damn good with a steel braided wire.

also as far as the "locks keeping honest people honest" sometimes we put locks on stuff to find out who the dishonest people are, and still keep the valuable stuff in a more secure area, in which this case paracord may be the better option, cheaper then the steel cable.
The Skinnerz (author)  onikus5 years ago
 Thanks for the comments.
I tried the steel cable on the door and found a few things:
#  depending on how well the door fits, the cable may need persuading into       the right shape to go over the door with  pair of pliers.
#  paracord should still be used on the handle as the cable will ruin it.
#  if you do this, it is easier for the anyone trying to break in to just unscrew         the handle (this can be made very hard by using some thread locking             compound to stick the piece of square bar inside the handle onto your             side of the door).
#  steel cable really damages the top of the door, so the piece of tin plate on     the top of the door is needed.
#  knots don't work too well in steel cable, so some of those crimp on type         things are needed.
The Skinnerz (author)  The Skinnerz5 years ago
sorry about all the random gaps in the comment, as the editor does not like indented text.
Truehart5 years ago
Is this a "keep the honest people honest" lock?  I could very easily see someone cutting the lock off with a knife or even a lighter.  I might be missing something, though. 
The Skinnerz (author)  Truehart5 years ago
 This is mainly intended as a deterrent, as if you have anything worth stealing, you can probably afford a stronger, more permanent lock, although it should work better with thin steel cable such as that found in bicycle brakes, but then it wouldn't be using paracord. Also, the inside lock is pretty strong, and seems to hold up as far as the handle itself will.
 I was thinking the same...
uberchoob5 years ago
ALL locks keep honest people honest, it's just that some are designed with less honest people in mind =)