A Good Sharp Knife
By Cliff Jacobson
Quick! You're going on a wilderness canoe trip. Besides your paddle and PFD, what tool do you value most? If you said "a good sharp knife", you're in agreement with the experts. Most people use a mechanical device of some sort to sharpen their knives. This is fine as long as "moderately sharp" is good enough and you have space to carry the sharpening tool. Actually, it's easy to sharpen a knife to a razor's edge. All you need are the right tools and practice.
This method works with any non-serrated blade.
A medium-grit and fine-grit whetstone. You need a coarse grit stone only if the knife is badly nicked or very dull. The quality of the abrasive is more important than whether the stone is natural or synthetic. Indeed, Amazon natives use water-worn rocks to sharpen their machetes-and they obtain whisker-sharp edges. Use water to lubricate diamond stones and cutting oil or WD-40 on natural stones. For safety, your stones should be at least six inches long.
Important! If you want the finest edge - and the ability to sharpen your knife in the field - don't ever use an electric sharpener on the blade! Why? Because the angle cut by machine is difficult to duplicate by hand. And never use an abrasive power wheel on a good blade. You'll ruin it beyond repair!
To check for blade sharpness: A knife is considered sharp if it will shave hair from the back of your hand. A less barbaric method is to shine a bright light on the edge. You should see no flat spots, no inconsistencies... nothing!
- Begin with the coarse stone. Raise the back of the blade about 15 degrees and cut into the stone. A trick to maintain the proper angle is to adjust an overhead light so that it casts a shadow along the back of the blade when the blade is flat on the stone. Raise the blade until the shadow just disappears and the angle will be close to correct. Another trick: If you set the back of the blade of a Swiss Army knife on the edge of a penny, the sharpening angle will be about right. Hold this angle while sharpening and you're good to go. Note: The "penny angle" method works only with narrow blades like those on Swiss Army knives. Exotic-looking tools that clamp to the knife blade are sold for the purpose of maintaining the proper sharpening angle. These tools work great for people who don't know how to sharpen knives by hand!
To sharpen Scandinavian-style blades: Do not use a 15 degree angle. Instead, hold the beveled portion of the edge flat against the stone.
- Hone one edge until a burr appears on the opposite side-you can feel it with a finger. Then hone the other side until a burr appears. Switch to the fine stone and continue sharpening, alternating sides every few strokes until the burrs are gone. Maintain a film of oil to float away steel particles that may otherwise clog the pores of the stone. Clean the stone (wipe off the surface and apply clean oil) frequently to keep suspended grit from dulling the sharpened edge.
- If you want a polished razor edge, finish honing on a superfine Arkansas stone, then strop the sharpened blade on a piece of leather. Strop the edge away from the leather-one stroke per side.
- Grit clogs the pores of sharpening stones and they become "finer" (smoother) over time. You'll prolong their life if you occasionally "boil them out." Simply submerge the stones in a pot of boiling water (with a few drops of detergent added) for a few minutes.
- Sharpening (butcher's) steels do not sharpen a knife; they merely realign the microscopic teeth of the edge. A steel is handy for touching up a knife (it's simply a coarse version of a leather strop), but it can't take the place of a genuine whetstone.
Cliff Jacobson is a professional canoe guide and outfitter for the Science Museum of Minnesota, a wilderness canoeing consultant, and the author of more than a dozen top-selling books on camping and canoeing. Visit his website at: www.cliff-jacobson.com
Cliff's Books & DVD's Available from Paddling.net
- Boundary Waters Canoe Camping
- Expedition Canoeing
- Forgotten Skills DVD
- From Here to There: Canoe Basics DVD