Monday 26 August 2019

Little problems, little fixes.

15,000 grit Shapton Pro on a Zero Tolerance folder.


    Hi there, the purpose of this post is to tell you that we experience sharpening issues, I do anyway, and this is usually how I get around it. So what is a sharpening issue?
    I just mean that sometimes the edge isn't up to par, something is going on that is preventing the knife from being as sharp as I can normally get it.

     When this happens it is almost always a result of the steel, the knife being resistant to abrasives and this is a common problem on lesser quality knives yet these make up a very good portion of the knives that we own and the ones that I personally sharpen. 

    There is a simple lesson to learn that solves these issues and I carry it with me on every knife that I do.




        When I sharpen a knife, and every knife that I sharpen is pretty dull, I always inspect the edge first just to see where I should start. I choose a sharpening angle, which for softer knives will be between 15 and 20 deg per side and I check the knife for anything that will hinder the sharpening process. If there is something, chips, bend, tip issue,  I deal with that first. I also check to see if the knife needs thinning, if yes, I take care of that first, I will thin on coarse stones and then refinish the blade with sandpaper and then sharpen.


     I choose my coarse stone which will be from 220 to 800 grit depending on the edge and the steel.  Shapton Glass 220 is usually the first one I go to or it could be a SG 500 which I love.  If the burr formation is taking a long time I may switch to a different stone, the Gesshin 400 or my new Morihei 500 that I got from Tosho Knife Arts, it's really good. 

Morihei Hishiboshi 500

    I start the sharpening process using the same technique that I've used for the last 10 years with minor tweaks within that period.  If you are just starting it is important to focus on the goal, the goal being to re-establish the primary edge and to do this we need to bring Side A and Side B of the knife together as precisely as humanly possible at the Apex of the knife. Our levels of precision will differ but we don't have to be perfect here, we just need to get those two sides back together and form the new edge, the microscopically thin line that we call the Primary Edge.

    Also, know that this involves the BURR and there are three aspects of the BURR that needs our attention and understanding of:

1. BURR FORMATION;
2. BURR DETECTION; and
3. BURR REMOVAL.

    I select my SA (Sharpening Angle) and go for it, I'm shooting for burr formation and this will take me 1 minutes or 8 minutes, there is no rush but it's essential to accomplish this goal and it will test my patience and my persistence will prevail. 

12 Deg dream knife sharpening angle


   Once I have formed a burr, the Primary Burr which runs from heel to tip and is consistent in size, and I have done this on both sides, I start the Burr Removal process, on the same stone. I've reduced my pressure and just keep reducing it, shaving that burr off and moving towards the final goal,  a clean edge, as clean as my skill allows it to be.

     Now before I move on to a 1, 000 grit stone, which is most often the case, I do the LIGHT TEST. This simple, quick check has greatly improved my edges, it's made a huge difference. I am not suggesting I created this test at all, smarter sharpeners than I am have been using it for years. 

    As the final test before switching stones I look at the edge under a good light source. I'm holding it straight up and down and looking for any light, any reflections. If the edge of the knife is a toothbrush, the light would be the toothpaste that hasn't been completely washed off yet.  Sometimes it is hard to see the light, it may not be there at all which means I have successfully brought Side A and B together, there is no lingering metal fragments clinging on to the mother ship. These metal fragments creating the reflections have to go and I found it better to do this on the first stone rather than rely on finer stones.

So if you are having a problem attaining the sharpness that you are used to, try this simple check. 

   If I do see light, I just go back to the same coarse stone, do a little more grinding at a moderate pressure level and keep checking the edge under the light. It doesn't take long and when I am done, the knife is going to be quite sharp and it is time to move on.



       Once I start with the 1,000 grit stone I am using a slightly reduced level of pressure than when I started. I am still going to produce a tiny burr, a micro burr that can be hard to detect but by doing so I know that I have reached the edge of the edge. 

   If your knives are not cutting it, make sure that your angle is not to low, you need to be reaching the very edge of the edge and a sharpie will help here. If the angle is to low, you may just be hitting the area behind the edge of edge, the "shoulder" of the knife and this is not doing anything in terms of sharpening, you're off target.

   I continue this way, I form the burr, I detect it and then I do the most important part of the entire process, I remove it and I really concentrate on this part.  I personally do this by using ever diminishing levels of pressure. I don't get a wire edge or anything nasty this way,  I don't have to run the edge through a cork which always seemed counter productive to me. 

    I always finish on a leather strop usually loaded with green paste, chromium oxide which is easy to get.  This helps clean the edge and will improve the level of sharpness.

   The trick to sharp knives is to accomplish the goals on the first stone, to form, detect and remove the burr and in doing so, to re-establish the primary edge. To get the knife as sharp as you possibly can on the first stone. If the edge doesn't feel really sharp, don't think that you can just rely on the next stone to rectify the problem, it won't. It's a matter of patience and diligence on the first stone used and covering basics. 

   If you are starting off, don't fret about the level of sharpness you get, just focus on technique and the building of sharpening muscles. You've probably seen a million videos of people slicing a tomato without holding the tomato. Big deal, don't worry about that, it's not a goal you need to be thinking about now. Stuff like that will come much further down the road, I sharpened for years before I worked on Parlour Tricks and I got over that.
     I don't care if my knife will fall through a tomato, I want it to fall through 100 tomatoes and that just takes time and a constant reinforcement of technique through practice and focus and enjoyment, above all, enjoy it. If you don't enjoy it, take a break and then go back at it.

Easy Peasy

Thanks for being here.
Peter Nowlan