Sharpening the Tools

There is no way that I can get into the kind of detail needed for sharpening without ending up with a book-length section. As it turns out, many people have already written a books on sharpening, and done a better job than I could. So the most important part of this for the beginner is the recommendation that the first thing you need to do is learn to sharpen.  A class on sharpening is available at the Woodcraft Store in St. Louis and I'm sure others around the country.  Clubs have members that can help and assist.  Our club, the St. Charles Area Woodcarvers, has a sharpener available at all meetings and several people who can assist you.  But, no matter what book and sharpening system you end up using, the fundamentals remain unchanged. Learn them.  Understanding the principles is a must.

This is a brief description of the principals and the process.  It is applicable for all sharpening, even "V" tools.  However "V" tools  require a little more discussion on the bottom of the "V" and we aren't getting into those because they are very hard to make.  This procedure is the same for sharpening systems, stones, or whatever you may have.  It is always done taking care not to over heat the tool.  The faster the system, the softer the touch must be.  Use less time on the wheel for each grind.  My favorite system is my home made 300 rpm sharpener shown in the Shaping section.

You grind one edge on the stone or wheel until a burr (aka "wire") is formed on the other side of the edge. You can see and feel the burr with your finger. The presence of the burr means that the steel is thin enough at the top that it is folding over slightly. Some instructions say that you go one side only until the burr is formed; if that takes 10 strokes or 50 strokes, you keep going until you get a burr, period. Only then do you flip the knife over and do the other side. 

I prefer to make a few strokes on one side, or until the burr is started.  Then make a few strokes on the other side.  This keeps both sides of the blade even.  Continue alternating until the wire is even over the entire length of the blade.  (As shown)

It is hard to see (much less photograph) the burr on a blade.  They only show in a bright light with the blade held at just the right angle.  You will have to play with this a little to see it.  A 5X or 10X magnifier helps a lot.

If you stop before the burr is formed evenly over the whole length of the blade, then you have not ground all the way to the edge, and your knife will not be sharp.  The forming of the burr is critically important -- it is the only way to know for sure that you have sharpened far enough and evenly enough along the entire blade or cutting edge.  For gouges and chisels, only the back (or beveled) side is ground.

Having raised a burr, the job now is to progress to finer stones, sand paper, or strops, in order to make the edge smoother and remove the burr. Run the blade along the stone or on the leather wheel switching to finer grits, until the burr is gone.  For blades, alternate sides with each stroke. The burr is very thin and razor sharp, so it seems like an incredible edge. This is sometimes called a "wire edge". But being fragile, it will break off the very first time you use the knife, leaving you with an extremely dull knife. If you seem to be getting good sharpening results on your knives, but they are getting dull very quickly with little use, you may be ending up with a wire edge. If that's the case, you'll need to be careful and watch out specifically for the wire edge.  You should progress down to finer grits slower, using more strokes or time on the wheel to give each grit more time to hone (and remove) the burr.

On a badly-worn or damaged edge, I'll typically start with a medium stone, then move to 400 grit sandpaper, then to a coarse compound on the leather wheel, and then to a fine compound leather wheel.  Finally, for a more polished edge, I will use the buffing wheel with a very fine polishing compound.  However, once my tool is sharp, I re-sharpen them before it gets too worn down. In that case, I can usually start on the fine grit leather wheel and then give it a quick buff.

On other sharpening systems, these same fundamentals still apply.  The burr must be created evenly and along the full length of the cutting edge.  Then, with successively finer grits, hone and strop the burr off completely.  Never use the tool until the burr is honed off.  The burr will break off and you will have a very dull tool.  The only way to correct this is to start back at the first grit and re-generate the burr.

Some tips and tricks

If you want to determine if you are sharpening at the same angle that the blade or gouge already has, try this easy trick. Mark the edge bevel with a magic marker. Then make a stroke or two on the stone or take a stroke on your wheel, or whatever. Now, look at the edge. If you have matched the edge angle exactly, the magic marker will be scraped off along the entire edge bevel. If your angle is too high, only the marker near the very tip will be gone. If your angle is too low, only the marker away from the edge will be gone.

One trick to freehand sharpening is to use your thumb as a guide. I'll place the spine of the blade against my thumb pad. That way, I can feel the angle between the knife and stone or wheel, and make sure that it is consistent. Typically, the hardest part to freehand sharpen is the curving belly of the blade.  Keeping a consistent angle is more difficult when the edge isn't straight.  Your thumb will also feel overheating before it ruins your blade.

I hope this procedure helps you.  These fundamentals are essential.  Practice them and you will be rewarded with sharper tools and neater carvings.