Friday, September 7, 2018

How I fixed my deadbolts with a pencil

Recall from my previous post about door locks that the pin tumbler locks that are standard on most doors these days use a rotating cylinder full of little pins that have to be correctly aligned by inserting the correct key.  Well, sometimes these little pins get kind of stuck because the lock gets full of grime, etc.  This makes it hard to take the key in and out of the lock.

Two of my deadbolt locks were having this problem.  The key didn't want to go in and would have to be jiggled around, and then it didn't want to come out.  Once it was in there, the lock turned just fine, though.  This is a symptom of stuck pins that need lubrication.

You can buy lock lubricant in a tube, but apparently they just use powdered graphite for this purpose.  It's nothing particularly special.  In fact, you can use a pencil "lead", which is actually made of graphite, for the same purpose.

I rubbed the tip of my pencil all over my key, put the key in the lock, and took it out again.  I repeated this a couple of times, and just like that, the problem was solved.  My key now slides in and out of both locks flawlessly.  Magic!

And now for some trivia: While pin and tumbler door locks date back at least 6000 years, wood-encased graphite pencils are much newer, dating from around 1560 in Italy.  Initially, these wood pencils were made by inserting a stick of actual graphite between two halves of a wood cylinder and gluing them together to encase the graphite stick.  Later, people discovered that you could powder the graphite, mix it with clay, and then bake it into little rods that were easier to work with.  The amount of clay could be varied to adjust the hardness of the pencil.