Sharpening tools woodworking

The cutting edge of a chisel looks, in cross section, like the apex of a long triangle. Although the meeting of the back and the ground bevel at the end of a 25 deg taper looks like a triangle, it does not taper to infinity.

The edge is of finite but very small thickness - just a few microns across. If the edge is thick enough to reflect even a cobweb-thin line of light, it is dull for woodworking purposes.

Why Sharpening Guides Make it Harder. The most important thing you can come away with from this lesson is the technique for holding and moving a tool on a stone. Most sharpening lessons deal with the technology and sharpening sequence and leave this part out. But free holding a tool consistently and easily is the key to sharpening easily and well.

It's not that difficult at all. There are a tremendous number of products on the market designed to hold a blade at a consistent angle to a honing stone. However, almost all of them share two important flaws: The jigs allow you to repeat a motion but always in the same part of the stone.

For waterstones this means the stones will wear in certain spots faster and require more maintenance. The second problem with honing guides is more subtle: The first time you sharpen you establish some sort of bevel. The second time you sharpen you need to maintain the same exact bevel; The important word here is "exact"; If it's not exact, you tend to create a secondary and then tertiary bevel at each attempt at sharpening.

This makes for much more work. Even if you can get really, really close to getting the same bevel, setting a tool in a jig exactly is tedious and very hard to get perfect.

And it takes time. You'll find it a great pleasure to be able to just take a tool and immediately put it onto a stone without having to worry about setting up a jig. Jigs and guides do have a place. We do use jigs for holding tools when we grind them and for really rough honing where a grinder is not available and we have to remove a lot of metal using a coarse stone. And we sell all sorts of jigs in our Museum Store. Therefore please realize we are not trying to present a "religious" argument but simply trying to show you how we make it easier.

An argument made against hand tools is that it's hard to make them work. A hundred years ago and more, people made hand tools work. They had no choice: they didn't have power tools. Woodworkers were able to be productive by having the right tool and developing the skill to maintain and use it properly. If you can duplicate that skill, you can be just as productive. Those products fall into three general types: wet-wheel sharpeners, powered sandpaper sharpeners, and human-powered honing guides you use with your own stones or sandpaper.

To help you decide which type and model is best for you, we rounded up dozens of sharpeners and spent more than a month testing them. Although some models can be used to sharpen jointer knives or lathe tools, we focused our testing on flat cutters, such as chisels and plane blades—the tools you'll likely sharpen most often. It takes a practiced hand to freehand sharpen without accidentally changing the bevel angle or putting the cutting edge out of square with the tool edge.

A wheeled honing guide, though, maintains the tool at the correct sharpening angle as you roll it back and forth over an abrasive. You can use them with sandpaper, oil- or waterstones, or even diamond paste, although models with widely spaced wheels may not fit on all sharpening stones.

What to look for: A rock-solid registration method—a fence of sorts—to keep the cutting edge square to the edge of the blade ensures accuracy and consistency, as does a tool-clamping system that holds all widths of tools securely. Narrow chisels also benefit from the additional stability of a honing guide with widely spaced wheels or a single, wide roller.

The fastest-growing category of sharpening systems, these powered units use self-adhesive sandpaper stuck to swappable spinning platters. By applying different grits to opposite sides of a platter, you can step up through the required three or four grits with only seconds between grits to flip or switch platters.

Because of the coarse to grit abrasives available--and the ability to quickly flatten tool backs during sharpening--these systems excel at restoring a dull, abused, or misshapen cutter. The platters on these dry sharpeners deftly walk the line between turning fast enough to remove material quickly and slow enough to not overheat the tool steel.

But they sling abrasive grit and steel filings over a surprisingly large area, so keep the unit isolated from the rest of your shop as much as possible. What to look for: Again, unless you're adept at freehand sharpening, look for a tool holder that maintains the blade's bevel angle and a square edge. And the ability to add a microbevel will help your finest abrasive grits last longer. A powerful motor allows you to bear down hard on the tool for aggressive sharpening without stalling.

Best buys: That all depends on your skill level and budget.