Friday, August 31, 2007

I've Been So, So Dull

I started my woodworking career in 1992, fifteen years ago now, and until the past month I've been working with dull tools.  Of course, I didn't know it or I wouldn't have been doing it, but the fact remains--I've never handled a truly sharp chisel or plane until very recently.  It's often said that a sharp plane iron can shave the hair from your arm or peel a small, continuous thinner-than-paper strip from your thumbnail's surface, but one can force even a slightly-sharp tool meet these criteria.

In the past I've worked my chisels and plane irons on all kinds of stones, always completely freehand.  While some master craftsman can produce a reasonably sharp edge this way, most mortals only end up producing a mildly rounded bevel instead of a true razor's edge.  Don't get me wrong--people will boast that their tools are sharp after honing this way, but they're just not.

I recently decided to work on my sharpening skills, and it's been an incredibly productive month.  The first thing I did was invest in the best honing guide I could find.  It's the Veritas MK-II system pictured below.  If you want sharp tools, buy one HERE.



Without getting into the details of how the guide works (you can find that info at the link above), suffice it to say that the honing guide provides a way to maintain an absolutely consistent angle between the stone and the tool's cutting edge. This eliminates the possibility of a rounded bevel. After honing on successively higher-grit stones, one can easily achieve a mirror-finish on the cutting edge and on the tool's flat back. Many people overlook this last point: Unless the backside of your iron, chisel, or machine knife is dead flat, the sharpness of the cutting bevel is basically irrelevant.

I've also been reading about and experimenting with different stones. I've tried a variety of oilstones (both manmade and natural), waterstones, and the relatively new 15- and 5-micron grit mylar-backed abrasive sheets. People can get very passionate about the benefits of this-or-that stone, but I'm convinced it doesn't matter a whole lot what one chooses as long as one starts with a fairly rough abrasive and ends with an incredibly fine one. Also, there's no reason, despite prevailing norms, not to go ahead and mix up different kinds of stones in the honing sequence. To wit, I'm now beginning with coarse and then fine India (both oilstones), progressing to black Arkansas (also an oilstone) and finishing with an 8000 grit japanese waterstone. This produces a chisel edge that can not only shave the hair from my arm, but even the stubble from my chin. Yes, I tried it!

If I'd been able to sharpen tools this effectively 15 years ago, it's hard to calculate how much fretting and gnashed teeth I might have saved myself.

4 comments:

clayb said...

welcome back!

The Wood Mechanic said...

Thanks, Clayb!

cfmelton said...

HI, I'm a dedicated woodworker and agree whole-heartedly with your conclusion of free-hand sharpening. I have been using the previous generation Veritas jig for about 6 years and have been well satisfied. I would like to mention that wet/dry sandpaper is a very good and economical alternative to all stones. I also put a link to your site from ours. Check it out at www.my-tool.info/blog

The Wood Mechanic said...

Thanks for your comment, cfmelton. I'm looking forward to checking out your site!