Well, we’re going to talk about honing, the second part of the Gateway skill of sharpening. But to start off with, we need to make some “hardware” considerations. We need to take a look at a variety of honing media. There’s a lot out there, much of it accompanied by a fair amount of hype. So we’re going to “cut thru the crap” and take a look at reality.
There are a couple of things we need to keep in mind while making our investigation. There are two considerations when sharpening tools, the actual sharpness of the edge and durability. Roy Underhill uses an elegantly simple illustration to demonstrate the ideal tool edge condition and hopefully he won’t mind if I “paraphrase” him;
Also, the speed with which you can “refresh” an edge tool has a tremendous impact on your productivity and creativity. My goal is to spend as much time as I can working the wood, not sharpening the tool. I’m going to assume that’s your goal as well. That said, I’m going to immediately rule out one method of honing that has become very popular, especially among amateur woodworkers, the “so-called, Scarry Sharp System”.
In my experience, there are a number of ways that folks can derive pleasure from woodworking. Some folks simply are driven by their creative muses to be constantly making stuff. Some folks love to collect tools. They love the history. They love to possess something that ties them to a distant past. Anyone who loves working with handtools has an understanding of and a little bit of the collector in his or her own nature. Some folks really like to sharpen tools. They can usually be recognized by the lack of hair on hands and arms. These folks love the Scarry Sharp System. It can produce incredibly sharp edges. However, in many cases the practictioner overlooks the need for edge durability. It is truly impressive to see a hair split with a broad axe. But the reality is that the edge doesn’t hold up well when doing the hewing and shaping work that the axe is intended for. My other objection to the system is that it is expensive. Start adding up the cost of Wet/Dry sandpaper or expensive Micro-film that is rendered useless when it is unintentionally sliced in half. I won’t take long to see that a very expensive whetstone can easily be justified. BTW, I have my Grandfather’s oilstone, the one I learned to hone plane irons on. I have none of his sandpaper.
Okay, now that I’ve infuriated and/or alienated a substantial number of my friends and colleagues, let’s take a look at the pro’s and con’s of the honing media that strike me as both technically effective and economically justifiable.
These have been around since “who tied the pup?”. The name, oilstone, derives from the fact that an oily lubricant must be used during the honing process. The oil carries metal particles lost from the blade away from the stone’s surface. This prevents metallic glazing, which, can render a stone useless.
Natural Oilstones are generally novaculites. Recognizable varieties include (but are surely not limited to) Arkansas, Washita, Belgian Blues and Slates. Arkansas stones are the most widely recognized in the United States. These stones can range from moderately coarse (Soft white) to incredibly fine (Transparent black). Oilstones can vary dramatically in density and particle size/shape, with price varying accordingly. But as the adage goes, “you get what pay for”.
Manufactured oilstones, such as Norton’s India and Chrstylon, are available as benchstones, or as slipstones. These stones are usually somewhat less expensive than natural stones and offer good performance.
Oilstones, while somewhat slower than other honing media, wear exceptionally well and do not require frequent flattening. The can be a little messy due to the requirement for lubricant. But, there’s every reason to believe that any oilstone you purchase could end up on your grandchild’s workbench.
Waterstones can cut with amazing speed. They can create an incredibly polished edge. Waterstones require the constant presence of water on their surface (in some cases submersion during use) to carry away metallic waste. Best results are achieved when a secondary stone (similar to a chalk or talc) is ground on the surface to create a slurry which increases the cutting and polishing action of the waterstone. Waterstones can be naturally occuring or manufactured. Some waterstones can be prohibitively expensive. All waterstones degrade very quickly and require frequent flattening. Also, it is very easy to damage the surface of a waterstone while sharpening tools such as chisels or gouges. While offering incredible performance, when used correctly, the novice should understand that there is a high level of maintenance associated with any waterstone. Waterstones are also available in shapes such as slips, cones and files.
Even the most hidebound traditionalist has to make an occassional concession to technology, especially when it works well. And diamond honing media falls into that category. Diamond hones are available as bench stones, slips, files, rounds, et cetera. Diamond hones can be used with or without water. (If used dry, they can simply be scrubbed free of any glaze or build-up that has occurred). Diamond hones are extraordinarily durable, typically using steel or steel reinforced resin as the support for the application of graded diamond particles. Diamond hones are available in grits from the very coarse to the very fine, with an 8000 grit bench stone being available from one manufacturer that can rival the surface finish of a waterstone. They require only light pressure during the honing process, cut very quickly and will rarely, if ever, require flattening. The initial investment can seem a little daunting. But in terms of the performance/cost ratio, they are very difficult to beat. BTW, I have inadvertently knocked my 8000 diamond stone off my bench, picked it up and started honing again, while thinking “boy, I’m glad that wasn’t an oilstone, waterstone or ceramic that I just dropped”.
Ceramic honing media offer yet another option. They are reasonably fast cutting, produce an excellent edge and rarely require flattening. They should be used with water as using them dry will lead to glazing, which can be very difficult (if not impossible) to remove. While fairly durable, they can be prone to cracking caused by point impact (as in dropping them from the benchtop). Ceramic hones are available in all the usual shapes. They can be expensive but offer very good value for money.
SO, WHAT’S THE RIGHT ONE?
Well Virginia, there is no Santa Claus. There simply isn’t one right honing media. They all have there place and they all excell in certain applications. Plus there’s one other thing to keep in mind. You still need a grinder and/or coarse stones for initial edge shaping and the final step of polishing (stropping or buffing) will improve the edge, no matter what honing media has been employed.
That said, I have developed some “honing habits” over the years. They’re right for me, and they might prove helpful to you. But again, there’s no “right way”, only the way that works best for you.
For honing edge tools that can be held in a guide, like plane irons or register chisels, I prefer the large diamond honing plates. The cut fast and create a good edge with a minimum of fuss and provide an adequate support surface for the guide to roll on.
For honing cambered irons, tapered section chisels and gouges, or anything that I’m going to “hand-hold” while I hone, I still find oilstones give me the best results. Plus, I get the benefit of having a few “swarfy” oil stains to keep my old workbench lookin’ gnarly.
When I’m honing turning tools, I typically will use diamond “paddles” for outside surfaces and ceramic cones or rods for inside surfaces. The speed and ease with which they cut allow me to keep my turning tools consistently sharp. I prefer surfaces that are “off the tool”. My goal is to never have to sand a turned surface.
Sloyd knives, chip knives, detail knives and other carving tools all must be maintained to the absolute highest level of sharpness possible (while maintaining the appropriate durability). In recent years I’ve turned to ceramic stones to accomplish that task. However, stropping these tools after honing is always required.
Lastly, the waterstones. I got ‘em, I love ‘em and the finished edge that they can create. But when all is said and done, if I had to give up any of my honing stones, these are the ones that I could live without. And, if push came to shove and I could only have one variety…hmm… you’re just going have to make up your own mind.
But remember, “you can’t do your best work with dull tools”.