I recently got a Cold Steel Large Voyager Clip folding knife that came up pretty sharp, much sharper than my other CS Kobun Tanto fixed blade. I tried further polishing Kobun by hand with a Suehiro 1000/3000 whetstone but couldn’t reach that sharp. I’ll try further polishin with the incoming King 6000 whetstone, but would like to ask a question in the mean time.
The profiles of these two blades is different. Clip has a curved plain edge with straight grind, Kobun is a concave ground Tanto. So the profile of Voyager may be playing some role in cutting, factory grind may be more even or sharpened at an angle for paper cutting shows.
Anyway, I doubt I will be able to maintain razor sharpness but sharpen only up to a good slicing sharpness on fat blades. On Number 9 Opinel Suehiro 1000/3000 worked really well but it has a very thin blade.
How sharp do you aim to make your knifes? If a blade I sharpen can’t shave my arm should I cut myself for punishment? Will 6000 grit save my arm? Do I really have to have a fixed angle setup?
My Enlan is also sharp, even a handheld field sharpener sharpens it decently. It shreds paper, not at the first touch but with slight slicing motion. It works brilliantly as a knife, but it doesn’t shave me. I understand picking the right angle for the right job and steel is important. Maybe this is a sign of edge roughness. So should I really try to smooth it, or leave it there?
If you can shave with the knife you know you have a shallow/acute edge angle and have sharpened it correctly without rounding the edge.
When sharpening and especially when stropping the edge it is easy to round off the outer edge if you are new to sharpening. This will make the outer edge angle bigger and even if the knife is newly sharpened and stropped it won't shave. Can be hard to see without magnification. To avoid this you have to hold the knife at a specific angle when sharpening. Can be helpful to sharpen against a true plane. Like fine sandpaper on a sheet of glass. Or using a fixture to get fixed angles. When you strop/polish the edge, do it lightly and just a few strokes.
I usually only strop against my trouser legs. Or with toothpaste on a piece of carton paper. 4-5 light strokes on each side is enough to polish the edge without rounding it. Knives with very hard steel I may strop using some compound, like Autosol, on the carton paper.
A polished edge keep longer. But if you polish too much you may round and dull the edge.
I agree with Adoby. Hair shaving can be achieved on most edges if the steel and heat treat is at least average. If you have an edge that does shave hair, it will typically indicate that you are doing something right.
I try to get all of my knives, machetes, folders, and axes shaving sharp. I have only had a problem with blades that were of questionable quality.
A fixed angle system isn’t necessary and can’t be used easily on a convex edge. Grits are not equal either. The Spyderco Sharpmaker with fine rods will give you shaving sharp if you use it properly.
Needs got nothing to do with it, I keep all my knifes hair shaving sharp so no matter what knife i use I know what it will do when i use it. I use a 1” belt grinder to put a concave edge with a 400x –800x trizac belt and a quick buff with diamond compound with a little practice you can go from dead dull to shaving sharp in about 1 minute. For field sharpening i use this and can get back to shaving sharp pretty quick with the fine plate + leather strop and honing compound. The leather stropping/buffing is what removes the burr and takes from sharp to razor sharp.
I can tell from the “incoming 6000 grit” that you probably have the same misconception most people do. For normal working knives I sharpen with DMT Diasharp stones; start with extra coarse, then coarse, then fine only if it’s for finer work in materials that aren’t very fibrous. After I finish with coarse (or fine) I use a homemade leather strop with 3 micron diamond compound rubbed into it to break off the burr.
For those who are paying attention, that’s 325 or 600 grit before using the strop. Knives for normal work rarely benefit from any higher grits (some people will passionately argue with me about this, some will passionately agree) Hair on your arm will jump out of the way in terror if you do it right, but more importantly the edge is generally going to last longer because it’s effectively micro-serrated.
The problem most people have is that they start with too high of a grit, and then move on to the next grit before forming a burr (because it takes forever when you start too high), which means they haven’t actually sharpened the edge, just thinned the area behind it.
I agree with KKW, 400 to strop or buffing provides a shaving sharp edge with very fine edge serrations that make cutting even easier. Thats my most common recipe for my edc knifes as well.
Kokopelli, if you re interested in sharpening knives you might want to check Cliff Stamp channel on youtube and his forum too, he strives to approach sharpening and knife steel in in a more scientific and hype free manner than can be found anywhere on the internet except academic work, he has some very interesting data.
Cliff is regarded as one knowledgeable guy. I’m fairly sure he uses similar grits on working knives as I do if I remember correctly, but goes crazy high for things like chefs knives. I would follow his advice before my own most of the time. I believe after you read/watch enough of his work you’ll have as good a grasp as possible for sharpening, then it’s just a matter of practicing technique.
For chefs knives I’m lazy/like the aggressive cut in food at around 1000 grit, and I’m more likely to maintain them if it’s not so time consuming to resharpen.
I only use belts to get the first edge started on a brand new blade. My belt sander isn’t variable speed, so it’s too easy to overheat the final edge on steels with a low tempering temperature (most stainless). If you are using a carbon steel blade it’s less of a concern usually, but still requires some practice and a light touch.
Wow, thank you for your valuable replies. 400 –600 sound like quite a coarse grind. I am surprised you get razor sharp results out of it. My expectations would be microserrations that would work well on a kitchen knife but nothing further.
My first graded whetstone is this Suehiro 1000/3000 in fact. I have a local natural stone which seems to have a coarse grit but works really well to revive old kitchen knives, another local stone with finer grit other is an Opinel Lombardy Stone which is more refined. 1000 grit side of Suehiro was quite smooth to the touch compared to these stones, so can a true 400 grid be finer than I thought?
I subsribed to Cliff’s channel. By a couple of his videos I watched so far, I can say he sounds quite sensible. I shall study further on cheaper blades before grinding my Kobun once again
I tried stroking a blade with my pant as the final step and saw that it worked for cutting a few more hair. But, won’t a blade this dependent on the last strokes loose its razor sharpness in a couple of cuts?
You probably didn’t remove the burr completely and its turned over on you making it extra dull. You need to apply some pressure while stropping to get it to work. If you dont have a leather strop or buffing wheel&paste try cardboard, it works good in a pinch and its always available. See Emerson’s sharpening guide here
If you sharpen razor sharp properly your edge will last quite a while if you have a decent steel in your knife.
