Hello from over the Tasman. I enjoyed the tone of your opening post and its reference to 'down to earth' practicality. Good on yer, mate
Here's my view. I may state it like I know everything...but I don't. However what I'm saying has worked for me. I am certainly open to new ideas, and I would welcome feedback about what I've written below.
I have owned many knives, and I've used them a lot. I hunt, fish, trap, whittle, make bows and arrows and just generally muck about with knives. And I've been a fairly frequent knife user since the early 1960s.
It is only in recent years that I have even been aware of the various edge geometries that get so wisely debated. It may well be that a convex knife edge is better for some things, but I've never really noticed. I can certainly accept that it should be nice strong type of edge, and if I had to name a theoretical favorite this would probably be it. I may already have put a convex edge on my axes and some of my knives inadvertently just by being inconsistent with the use of a sharpening stone. In fact with axes, it may well be that I've been subconsciously trying to achieve a bit of a convex edge.
As a fitter, I has generally been my aim to get edges that are somewhat convex when I sharpen a cold chisel. I believe that these edges are stronger.
It was only just this year, I think, that I deliberately set out to put a convex edge on a knife by drawing it backwards over some fine abrasive paper that I had sitting on a soft surface. The edge looked wonderful (mind you, all sharp edges look good to me), but I don't think I noticed that it cut better.
To sharpen a knife that is really blunt, I might first use an electric bench grinder or even a hand-held disk grinder....but I am careful not to overheat the edge. If the knife is soft enough to file, I might file it.
Next comes a flat bench stone (or a sharpening stone, whetstone, Arkansas stone, India stone or whatever type, brand or name you want to use). I'd generally start with a fairly coarse one. If the stone is hard and flat, I will keep pressure on the blade as I move it forward over the stone (ie, as if I were trying to cut a slice off the stone). If the stone is very soft or the surface is at all uneven, I will only apply pressure to the blade as I drag the edge over the stone. If you push the blade into a soft or bumpy surface, I think it is possible to damage the edge. It is perfectly OK to drag a blade instead of push it, although you are probably more likely to get a fine 'feather' of steel at the edge this way. I generally 'drag' rather than 'push'.
If the height of the back of the knife varies a bit as you hone, you may well be generating an edge that is at least slightly convex. If you actually want to try to generate a convex edge, then it may be easier to achieve if you drag over the stone rather than push.
(I worked in a fish processing plant. We had some very experienced knife hands there, and some would drag the blade...and hell the blades were sharp. Maybe these guys actually created slightly convex blades this way. Our factory hone stones developed big hollows in them).
When the edge of the blade is looking good after honing on the coarser stone, I might then move to a finer stone if I can find one. But the work on the coarse one isn't finished until you can see that the grinding has gone right down to the edge. And you shouldn't be able to see wide patches on the edge...it has to at least 'look' sharp.
A few strokes on a finer stone may be enough. If you havent got a fine stone, dont worry. Just make your last few strokes on the coarse stone a bit lighter so that the grit doesn't dig in as deep. The knife will still be deadly.
What type of edge am I grinding? Dunno. Maybe someone has given it a name. The intention of this type of grinding is generally to have two flat surfaces heading at an angle to meet at the edge. In practice, they probably aren't perfectly flat as mentioned earlier, and frankly I don't think it matters much for most purposes.
Here's my take on it. The sharper the angle, the more likely it is to slice better (things like tomatoes and meat anyway). But the edge is comparatively weak. It may be able to bend at an angle to the plane of the blade. Sometimes you may feel this bent bit on one side of your blade but not the other if you run your fingernail down over the edge from the back of the blade. The bent side may shave little bits of nail.
So if you have a fine, thin edge it will cut soft things easily...but when the going gets tough, the edge is likely to bend. If an edge is thin yet hard enough to resist bending, then bits might break off the edge when doing hard work.
A less sharp angle coming to the edge will be more durable, but it is less likely to be good for slicing.
Now... razor sharpness.
I've talked about the bent-over edge. Another thing you may get but not easily see is the 'feather' edge that I mentioned earlier. Both these things have to be sorted out if you want to shave.
If you've ever seen a feather of steel, then you are probably at an advantage when it comes to understanding knife blades. This feather is very thin, and it simply seems to just get bent back and forth as you try to sharpen the blade. By slicing the knife into a hard, flat stone with a fairly fine grit, you are likely to remove the feather, especially if you make this very last part of the edge a bit 'blunter' in angle by raising the back of the blade a bit as you hone. Not many strokes should be needed to remove the feather. And both sides should be honed to keep the edge symmetrical.
Just like you can break wire by bending it back and forth, you can also break off a feather. Stropping on leather may do this, although the stropping may also finely abrade the edge...which is a good thing. You can also 'strop' by dragging the blade backwards over wood or cardboard.
A sharpness test which I find practical is to drag the blade edge down your thumbnail (not like slicing....scrape the blade sideways). Hardly any pressure should be applied. If the blade grabs, it is fairly darn sharp. If it skids off, it isn't....it may have a bent or worn edge.
I use a butchers steel, mostly, to get a shaving edge... I did read the other day where a manufacturer of good knives says don't use a steel on my knives...but I am unsure as to why he would have stated that.
It would be easier to show you how I use a steel compared to describing it over the internet (send me the air fare
). I hold the steel in my left hand, more or less horizontally. The blade of the knife sits near the tip of the steel... the bit touching for a start is right next to the handle...the 'base' if you like. The back of the blade is raised (to a height that you like to get a good edge angle...but a bit steeper than the ground angle), and then swept down the steel. I pivot the knife in my right hand ....for a start the blade is at right angles to the steel, but at the end of the stroke as the point of the blade is just leaving the steel, the blade might be at an angle of 45 degrees to the steel.
I slice one side of the blade along the top of the steel, then I slice the other side along the bottom. I do it several times, quite fast.
I have heard it said that you should feel the steel 'bite' into the blade...and if you don't feel that bite then things aren't working too well.
Now having said all that....sometimes my first strokes along a steel might go backward in an attempt to straighten any bent bits of blade.
My first strokes on a steel are likely to be done with more pressure than my finishing strokes.
Generally a steel will bring a nicely honed edge to hair-shaving sharpness, but sometimes I find that it doesn't. So maybe I will just use the blade as it is, or if I really get a fixation for shaving sharpeness, I may go and do a few more strokes on a fine stone and then return to the steel.
Can you see that it may be a good idea to have the last fraction of your blade's 'wedge edge' a little more 'blunt' in angle to help prevent the edge bending? I guess that a convex edge achieves this automatically.
A buddy sent us a Tri-Angle Sharpmaker. I don't think that something like this is essential, but it certainly puts a good edge on a knife even if it takes a while. Maybe something like this would give you the desired edge without chewing off too much steel.
The only way to keep a knife sharp, no matter what the brand in my experience, is to not use it.
If you can picture what might be happening at the edge of a blade, you are probably in a better position to know what to do to sharpen it.
This is what happens when I stay awake all night. Apologies.