TLDR: Anything as hard or harder than steel can sharpen a knife. Softer materials, such as newspapers, can hone.
In honor of my recent binge of MacGyver on Netflix (viva technology!), I’d like to share with you the secret about sharpening and honing knives: harder objects will sharpen softer objects, and softer objects can hone harder objects. Voila! You are now smarter than 90 percent of the consumer knife market.
I’m oversimplifying here, but it’s true. If your character is in a pinch and needs to sharpen or hone a knife using only mundane objects (i.e. not traditional knife sharpening equipment), here are a few suggestions.
The Top of a Vehicle Window (Hone or Sharpen)
The glass along the top of a vehicle window is rough and sturdy, which will hone if not outright sharpen a blade. (Remember, there’s a difference between honing and sharpening a knife.) However, please don’t test a blade’s sharpness by cutting your arm hair like the guy in this video.
The Spine of Another Blade (Hone or Sharpen)
The “spine” is knife talk for the unsharpened top of the blade. This metal-on-metal action can do the trick when the character is carrying two knives.
The Sidewalk or Other Concrete (Sharpen)
The aggregate and cement in concrete are hard enough that some burgeoning knifemakers actually made their first knives by sharpening pieces of metal on the sidewalk. No, really. This is a common thread to the knifemaker stories I’ve encountered working at BLADE.
A nice, flat igneous or metamorphic rock (you remember those terms from high school science, right?) can be ideal for freshening up that dull blade. Sedimentary rocks can work, too, but they can crumble. Rocks are how people across the planet sharpened knives and other edged tools for eons, and they work just as well today.
The Bottom of a Coffee Mug (Hone or Sharpen)
The bottom rings of coffee mugs are unfinished, leaving an easy-to-work-with radius of rough ceramic for sharpening or honing knives. I’ve tried this myself a few times on a couple beater knives, and I wasn’t as impressed by the results as this Youtuber. For writing fiction, though, it could be just the trick.
A Nail File (Hone)
The grit in a typical nail file can do a decent honing job, but I doubt it’ll outright sharpen a knife. It’s best suited for refreshing a blade.
Sandpaper (Hone or Sharpen)
This is one notch above the nail file, and it could sharpen a knife depending on the grit.
Corrugated Cardboard or Thick Paper Packaging (Hone)
There’s a reason knives go dull so quickly when they’re used to cut up cardboard. Cardboard is full of abrasives that can play to your advantage when used like a honing strop.
For honing (not sharpening), newsprint is surprisingly effective. When I sharpen my knives at home, I start with a coarse grit sharpener and end with a sheet of folded newspaper.
Leather belts bring to mind those old barbershop strops, but any type of taut belt can be used in a similar way.
Leather Shoes (Hone)
I’ve not tried this, since I don’t have a pair of leather shoes, but I’ve heard this method is valid. It works similarly to leather belts and strops.
The flat surface of lumber or other wood can hone a blade’s edge, although the character should take care not to cut into the wood in the process.
It’s a little morbid, but calcium-rich bones can provide a hard surface for freshening up a blade. Let your imagination be your guide with this one.
The general rule of knife sharpening/honing can be applied in more ways than the ones listed here, which is why it’s good to know for writing fiction. Remember: harder objects will sharpen softer objects, and softer objects can hone harder objects. If you’re confused about the difference between sharpening and honing, check out this post.
Get the Book
The Writer’s Guide to Weapons: A Practical Reference for Using Firearms and Knives in Fiction (Writer’s Digest Books) comes with everything but the ammo. Pick up a print or digital copy from these fine retailers: