Best way to sharpen?

October 27, 2008 11:21 AM

I have a bunch of dull knives, chisels, etc. I think I'm looking for a bench grinder. Used? New? How do I use it when I've got it?

I have a few chisels in the shop and a few knives in the kitchen that are getting dull. I've tried sharpening by hand on a wetstone, and it helps, but I don't have the steadiness of hand or the patience necessary to get a good clean edge.

I'm thinking about getting a little bench grinder. Are they worth picking up used, or are the Craigslist models likely to be burned out and useless?

When I get one, assuming that's the right thing for me, how do I use it? I understand the general principles of sharpening. What kind of technique should I use with a grinder?

posted by echo target to home & garden (13 comments total)

A bench grinder is useful but it will ruin a decent kitchen knife. I am also too impatient to sharpen by hand, and use this. Previous askmes are here and here.
posted by TedW at 11:45 AM on October 27, 2008

This is the type of machine to use, it has a wet wheel that preserves the temper of the steel.
posted by hortense at 11:50 AM on October 27, 2008

Ceramic crossbeam sharpener. If you have a basic edge, four or five passes through one of these (or similar) should keep you happy for a while.
posted by rhizome at 11:53 AM on October 27, 2008

I use the Spyderco: http://spyderco.com/catalog/details.php?product=77

It takes the bad hand/eye coordination mostly out of it, allows you to do chisel grinds, primary and secondary bevels, scissors, fish hooks, etc and it's fast. You want to use a grinder or whetstone on something like an axe, chisel or shovel, though.
posted by paanta at 12:04 PM on October 27, 2008

The Complete Guide to Sharpening is rather good.

For really dull, dinged-up edges, I like to us a tool file instead of a grinder. It's a lot quieter, and has a tad more control.
posted by scruss at 12:13 PM on October 27, 2008

So it looks like there's no tool that will do both kitchen and workshop blades, then?
posted by echo target at 12:14 PM on October 27, 2008

A bench grinder usually has a very coarse stone and removes a lot of material in a hurry. It's mostly for setting a rough shape and taking big nicks out of lawnmower blades and axes. Sharpening kitchen knives takes a much finer stone. They also go way too fast, which heats up the steel and can destroy the temper of your blade if you.
If you're looking for "big piece of machinery that sits on my workbench and makes things frighteningly sharp," you want to visit your local woodworking shop and look at a horizontal wet stone grinder or a Tormek. The staff at said woodworking shop will likely be happy to show you how to use it, and may offer classes. If you're looking for a more modestly-priced way to keep your knives and other dangerous toys dangerous, they probably can offer plenty of advice in that department too.
The minimal-cost approach involves a pane of glass and several grades of wet/dry sandpaper, with some sort of guide to hold the tool at a fixed angle. And for your kitchen knives, you shouldn't need to grind the edge more than once every six months as long as you regularly use a butcher's steel to reshape the edge before it gets too dull.
posted by leapfrog at 12:21 PM on October 27, 2008

As long as you're comparison shopping, consider the cost of having a professional do it for you.
posted by nanojath at 1:04 PM on October 27, 2008

A knife shop or decent grocery store can do it for cheap.

Cook's Illustrated recommends two ends of the spectrum - the $12 Accusharp, which has a simple carbide V you swipe over knife blades a few times, and an electric sharpener (Chef's Choice 130 or 120). Both of those are in the $130 range.

For your kitchen knifes you also want a steel. But you need a sharp blade before a steel does any good.
posted by O9scar at 3:23 PM on October 27, 2008

bench grinders will ruin your knives. even in you manage not to hack your blade into bits, the speed and heat will burn out the carbon in the steel and make it unable to hold an edge.

those V shaped "sharpeners" tend to be pretty useless as well

if you're serious about having some awesome blades, get a couple of really nice arkansas stones from your local woodworker's supplier and really take the time to get it right.
posted by swbarrett at 4:23 PM on October 27, 2008

The magic phrase for the sand paper and window glass thing that leapfrog mentions is scary sharp.

I usually use a Japanese wet stone that will get things sharp enough to shave with.

And I'm another vote for The Complete Guide to Sharpening.
posted by Kid Charlemagne at 7:52 PM on October 27, 2008

Thanks to everyone. I'll probably look up a copy of the Complete Guide for starters. The horizontal wet stone looks excellent, but I haven't got that kind of money to throw into it right now.
posted by echo target at 7:15 AM on October 28, 2008

I use a cheap hardware store oilstone for axes and really rough shaping when necessary; an 800/4000 grit combination synthetic Japanese waterstone for putting a fine edge on chisels, kitchen knives, and plane irons; and a 12000 grit natural waterstone for those times when I really want an edge I can be proud of. In a pinch, you can put a usable edge on a knife using the unglazed ring on the bottom of a coffee cup.
For most kitchen knives, putting your thumb on the back of the blade and resting the edge of your thumb on the stone as you take repeated slow passes is a good guide. If you want to make a secondary bevel, start with the back of the blade in the middle of your thumb, then move it to the top edge for the last few passes It isn't an accurate to .05% totally optimum edge but no matter how carefully you sharpen you knife you lose that .05% optimum edge the first time you hit a bit of dirt on the potato anyway. Learn to use a butcher's steel to restore the edge between honing, it saves a lot of time.
posted by leapfrog at 7:25 AM on October 29, 2008