We’ve all seen it before – the pocket knife that you couldn’t cut warm butter with on a hot July afternoon. It’s a little rusty, the joints are gunked up with who-knows-what, and the only thing it’s good for is opening letters. Almost as bad (or worse depending on your viewpoint) are the kitchen knives that can’t cut tomatoes, or anything remotely tough without repeated sawing.
There’s no reason it has to be this way. I think sharpening edged tools is one of the more useful outdoor skills, and it has a glorious payoff in the home as well. The good news is that it’s no longer an art practiced exclusively by mountain men who eat only bear meat. The old days of nothing but Arkansas stones and a little luck are over. It’s really not hard at all; you just need the right equipment.
Let’s start with knives.
The essential sharpening process isn’t rocket science. With an abrasive material, you remove a small amount of metal to restore a clean, sharp edge, and you remove this metal using a low-friction environment so heat build-up doesn’t destroy the temper of your blade.
This isn’t meant to be a piece on metallurgy. There are people way geekier than I who can give you a lesson on the finer points of the hundreds of different alloys with their various properties. It’s just about sharpening stuff.
My preference in a good knife is a high carbon content. Super-high carbon content knives are almost always not stainless, but will discolor over time to a dull gray. I happen to think they look beautiful, but that’s my opinion. They do rust if they are kept damp, but a little oil and a little care keeps them from rusting. Goat cheese will darken your knife immediately, so if you want to get a good patina on the blade, just slice off a hunk for your bagel.
Better knife manufacturers use a stainless steel with a higher carbon content. These are better called “stains less” steel, as they will rust if not properly cared for, but they’re easier to maintain than a pure carbon steel. Knife companies like Benchmade and Grohmann use a stainless steel with a carbon content that is very high, so the knife blade will last. Less expensive knives (low-end Wal-Mart pocket knives like K-bar, etc.) are low carbon content stainless and will not last under typical use, but then they’re hoping you’ll lose the knife before it breaks. Most people do.
Sharpening in years past was difficult, as it necessitated keeping the proper angle on the knife blade so that you had a clean, consistent, flat edge, rather than a rolled edge that dulled quickly. One tended, without any sort of guide, to rock the blade and create an inefficient cutting edge. A master carpenter could free-hand an angle like a machine, but most of us can’t.
Tools to keep this from happening are now common. One of the more popular sharpening tools is the Spyderco Triangle Sharpener (and others of its type). It works on the principle that while the human eye has a hard time eyeballing a 21 degree angle, pretty much everyone knows what a straight, right angle looks like. By angling the sharpening media, the guesswork and much of the imprecision is removed, and all you have to do is move the knife down the media in a cutting motion toward the base, alternating sides. If you follow the directions, you can shave with the blade of your knife when you’re finished.
I had never tested the angle of the Triangle Sharpener. I used a level to get a good reference for the bevel gauge, and referenced off that (I know it doesn’t look plumb…I promise it was). As you can see from the picture, the angle of the sharpener is just over 20 degrees. That’s a good angle for most tasks.
I often carry a Triangle Sharpener (it’s wee) when traveling to visit friends. I can usually sharpen every knife in the house in less than an hour or two, and they’re always grateful. It’s relaxing, fun, Zen-like work, requiring little skill but a fair amount of concentration.
Another approach is to lock down the angle using a guide. One such type is the DMT (Diamond Materials Technology) sharpening system, which uses a clamp-on guide to make sure you keep a consistent angle. You can choose an angle depending on the type of edge you want. The lower the angle, the sharper you can make an edge, but it is a less durable edge. Scalpels can be used for surgery, but they’ll dull in seconds if you try to cut something other than flesh. A meat cleaver wants a higher angle, because you want a durable edge, even if it’s not razor sharp.
Here’s sharpening in action with a Spyderco: