As your arm tires while sharpening your blade, it’s tempting to switch to a powered grinding wheel. Most people should avoid that urge. Warranties do not extend to knives that have been sharpened on wheels and damaged. The chance of scratching or chipping your blade goes up. So does friction, and that means your blade will heat up rapidly. Eventually, this could burn the temper from your blade and, in the process, greatly weaken it. That said, if you’re sharpening blades en masse you might have little choice. One of the best ways to approach sharpening blades in this manner is to remove the cover from your bench grinder and flip it around 180 degrees. This way, the wheel will travel upwards, rather than downwards, giving you more control and decreasing the likelihood of a chip in your blade. Be sure to get a wheel with a very slow revolution rate, or outfit it with an “electronic speed controller” available at most hardware stores.
Archive for December, 2007
What you’re looking for is water or “honing oil,” which is manufactured by several knife and knife accessory companies. There are two types of honing oil: water-based and petroleum-based. With diamond stones, use water or water-based honing oil. Petroleum-based oils work great with natural sharpening stones. If you’re out in the woods, you might spit on the stone before beginning. Keep in mind, though, once you’ve decided to use oil, stones don’t take to water very easily, so you’re going to have to stick with oil for the life of the stone.
Ask two different knife enthusiasts about using honing oil and they’ll tell you two different things. Some believe oil inhibits sharpening by never really letting the blade touch the stone — in effect, just polishing it rather than sharpening it. We’re of the other camp that suggests oil or water is a good thing. It lessens the friction you’re exerting on the blade, and that means it’s more forgiving if your hand slips. It’s also smoother and it keeps natural sharpeners clean by whisking away your excess filings.
Diamond sharpening stones are sharpening stones coated in micro-diamonds. What’s inside the “stone” isn’t necessarily a chunk of rock. It could be metal or a composite stone manufactured mechanically. Diamond is one of the hardest substances on Earth. By coating a stone in diamond powder, it ensures you’ll be able to sharpen even the strongest blade, and the porous surface provides an escape route for filings that come off your blade. This keeps gunk from building up on the stone and hampering its effectiveness. DMT sharpening stones are some of the most popular of diamond sharpening stones.
There are several choices, but few as universally relied upon as the low-tech sharpening stone. Diamond stones, which have a very fine grit, are used on knives that only need touched up. For duller blades, approach it much like you’re using sandpaper on a block of wood: coarse-grit stones first (grits of 400 or less); then progressively finer ones (600 and above). For a serrated blade, you’re going to need a cone-shaped taper sharpener which will be made of the same material as a regular stone. For big tools: sharpening pads. Some enthusiasts swear by using oil to sharpen their blades, others go with water, or — in a pinch — saliva.
Dull blades are a fact of life for every outdoors man. Another fact: If you neglect to care for your knife, you’re going to find yourself with a voided warranty or an unexpected expense when you have to shell out for a brand new knife. Taking the time to clean and care for your blade is a must!
