Drawknife Sharpening Question

[Bruce Ferm]

I’m using a 5” drawknife and to debark Red Oak, Apple, Cherry and Maple branches that I cut in mid-winter and have had drying indoors since then. The blade is tempered blue carbon steel, but the bark is hard and taking it off seems to be a pretty hard use on the drawknife. The blade isn’t getting dinged by this use---the edge is holding its original line, but it does seem to be getting dulled with pretty fair speed because of the hard life it’s living.

My guess is I’ll be best off sharpening the blade with 600 grit diamond or carbide paper and not wasting time/effort stropping because of the hard use I’m putting the blade to. Right now, I just don’t see any sense in treating this blade as if it was a Pfeil carving knife that only ever gets used on basswood.

Should I just go with the paper or would I be well advised to employ stropping as well? Thanks for your help.

[Doug Trembath]

Bruce, you are making the most base of cuts here, so, really, sharpness isn't an issue. Only when you are making cuts that really count is the fineness of the edge truly pertinent. When the knife struggles to make the cut you desire, sharpen a bit, but in this case you don't need exceptional sharpness. It would be removed almost immediately in any case, and provides you with little reward. Time spent sharpening is time lost, IMHO, if it isn't a finish cut.

A larger knife would aid in this endeavor, in my opinion, for many reasons, simply for the leverage and utility, but if what you have is a 5" knife, use it.

Too many times folks seem to gravitate to the sharpness issue, (obviously due to the lack of experience, or paying too much attention to sharpening threads on their favorite forums) but when you are doing gross material removal, it really isn't pertinent. Just refresh the edge sufficient to the task when roughing out elements, save the micro edge technology for the finish cuts that will truly affect the finished product. At that point, make it as sharp, and controlled, as you are able.

That being said, nothing beats a truly sharp, well-behaved knife when the cuts count. I really began to understand this concept when learning roughing out blanks for woodturning. The rough cuts don't require your edge to be that finely sharpened, and very often sacrifice that super-fine edge almost immediately, anyway, due to dust, dirt, and just common crud you need to force the knife (or gouge) through.

I keep my knives (and gouges) sharp, routinely, but when it come down to roughing a piece, I just go for it in the beginning, and only sharpen to the finest level needed until I get to the final cuts. That is when the sharpest edge wins.

If your knife will remove the bark and cambium layers, and allow access to the meat of the piece, you are good to go. You will be well served to find an acceptable level of sharpness which will quickly, and efficiently, allow you to accomplish the task at hand. This is what every apprentice learned quite quickly in ages past, (and hopefully in the present, as well).

This is much like the efforts so many folks make to have their Jack planes take sub thou shavings. It isn't about smoothing at this portion of the journey. Remove the waste in the most efficient manner, so you can get to the part that demands excellence.

Don't get caught up in the need for 0.0005” shavings when they are not called for. When theyare, sharpen such that you can achieve them, and enjoy the process of creating them, as well as the satisfaction of the finished surfaces others only dream of.

Doug Trembath

[Doug Trembath]

Sorry for the rant, folks, but just today I had to make the same argument to a recalcitrant student, and didn't see it as a rant until I re-read it after posting...

My apologies, folks...

Doug Trembath

[John Coloccia]

I would make it as sharp as you can. At a minimum, the edge will last longer and will be easier to maintain. If you KEEP it sharp, by stropping as soon as you detect the slightest dullness, you'll find yourself having to sharpen far less and you'll spend a lot more time actually working. I rarely have to take my tools to a stone, but I do keep a strop right on my bench.

[Prashun Patel]

There is a difference between the demands on a turning blade and a flat blade. I too sharpen my bowl gouges only to 80. I don't hone them. But those tools are meant to withstand force, and the force of the lathe propels the piece fine through a blade that isn't honed; it will cut just fine (for me and you at least).

With a drawknife or spokeshave or plane iron, I find that a non-honed blade has more resistance than a well honed one. It's shades of gray; for each person there's a point of diminishing returns. I find when I do not hone my drawknife or spokeshave blades, I have to 'press and pull' more than just pulling off curls. I just find a honed blade easier to pull and therefore easier to control - even for the roughing out.