Gregg776
@gregg776
active 3 years, 9 months agoForum Replies Created
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It could be that the knife has invisible stress cracks form a life of being abused and the diamond stone is merely breaking off chunks that would come off in time with any means of sharpening or thinning. There have been several discussions in the past on this forum about flattening the edge completely to get to new solid metal. Then re-sharpen as close to even on both sides as possible.
Similar chipping happens with a blade that has been overheated on a mechanical grinding wheel without coolant and somebody polishes out the heat discoloration to cover their mistake. Another cause is using the knife as a pry-bar near the edge (my wife would do that), or improper use of a steel.
Personally I would not go less than 18 degrees on a cheap knife then add a 20 to 22 degree micro bevel.
On the other hand the knife may be poorly heat treated and never be worth the effort except for the learning aspect. Inexpensive knifes are batch heat treated and this one may not have been in the right place to get a proper heat treatment.
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To sharpen the Miyabi 7000 MC knives, I start out at 13 degrees per side and run through the strops to 0.5 micron. I don’t change angle for the strops because I can’t get much less angle on my WE. I then finish off with a micro bevel using the 1000 grit diamond as close to perpendicular as I can using very very light strokes. For the bigger knives that I use I put a 15 degree per side micro bevel and for the smaller knives that my wife use, I use an 18 degree per side micro bevel. To re-sharpen I just re-do the micro bevel until I feel I should give the knife the full treatment.
Owning the WE has mitigated some of my OCD tendencies as I have come to realize that there is no perfect edge that will do everything and still remain shaving sharp; it is far easier to just re-sharpen when needed to the point of easily obtaining a truly wicked edge.
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There are a number of factors in play here. I may be off the mark on some of these items; cleaning the platens may have more than one step or solution depending on many things.
- If the knives you are sharpening are not cleaned of all organic material, you could be introducing a layer that can polymerize into pretty strong glue (think Elmer’s or hide glue) that may bind the swarf and require different cleaning methods than just removing clean swarf. Residue from tape, wood, paint etc. can quickly foul abrasives.
- The diamonds are attached with either a nickel or cobalt based alloy which may be attacked by strong acids; stainless steels have high nickel content and anything that may dissolve the stainless swarf (which has fairly high nickel content) may also cause some diamonds to fall off. Weak acids that don’t attack the matrix holding the diamonds may take a long time to be effective on a stone highly loaded with stainless swarf. If the swarf is mostly iron, a weak acid will work much better than on stainless. Personally, I like sulfamic acid which is not toxic, a little stronger than vinegar and doesn’t smell. It also comes in solid form which is easy to store and make up whatever dilution necessary; a drop of dish detergent for a surfactant would help. I use it for descaling my espresso machine which has a lot of different alloys in contact with the water and it hasn’t hurt it in over 10 years. When I was in the Navy, they used sulfamic acid to descale the evaporators that were used to distill sea water. Another choice would be phosphoric acid; I’d probably just use the metal prep variety that is made to use before primer on steel. Detergents made for dishwashers can be pretty powerful and may be a good solution but may attack adhesives over time. Careful research should be done prior to using anything that may affect the platens.
- The swarf has sharp edges and can be much harder than the matrix securing the diamonds; it can become embedded and very hard to remove. Swarf can load the pores of ceramic stones; it can build up on any abrasive medium and cause unexpected scratches. The solution is to use light strokes. I also like to keep my ceramic and diamond stones wet with water and a tiny amount of detergent to help wash away the swarf as it is produced and to keep the temperature down where metal is being scraped off of the blade. The water and detergent also helps keep debris from flying all over the rods and ball joints, but it can be messy and may promote corrosion.
- Swarf that isn’t cleared relatively quickly may expand as it corrodes making it much harder to remove. Abrasive cleansers may over time help erode the matrix that holds the diamonds.
Maybe Clay can show some microscope pictures of various stones before and after cleaning with various methods.
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I’ll take a stab at your problem, just bear in mind that this is my personal opinion and there may be better solutions.
First of all VG10 ans SG2 are very different alloys from the softer stainless steels in most Victorinox knives; in other words the Victorinox needs a steeper (or more acute) angle to stay reasonably sharp and functional. What you have done with the 15 degrees per side hasn’t hurt anything and may have actually thinned the cross section so that less effort will be needed to cut or slice. The problem is that the softer steel won’t keep the edge you have so painstakingly tried to give it even through the sharpening process and certainly won’t hold up to to actually cutting much of anything.
I’m assuming that your diamond and ceramic stones are broken in; that is they don’t leave scratches much larger or deeper than they are supposed to. The simple solution is to take your 15 degree fine edge and put a micro bevel at about 22 degrees per side with a diamond stone using very light strokes at close to perpendicular to the edge (not sweeping strokes) which will give the knife some tooth and resistance to the edge rolling over. I would start with 800 grit diamond and use some water with a little detergent on the stone to help lubricate and wash away the swarf. You may want to experiment with grit and angle a bit depending on how the knife is used and who is using it. The micro bevel you want should be barely perceptible to the naked eye, but wide enough to keep the edge from rolling over and making a wire edge. Search this forum for micro bevel, wire edge and obtaining a burr and you will have a better understanding of some of what is involved.
Remember to use light strokes and let the grit do the work; diamonds are not forever and pushing them too hard causes them to wear out prematurely but more important it causes the diamond particles to push metal much the same way a bulldozer pushes dirt leaving behind a weakened substrate and not lifting away all of the metal you really want to remove.
True sharpness is totally dependent on blade metallurgy, heat treating, who is using the knife, what they are cutting and their expectations of edge longevity. There is no magic one fits all solution.
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I only use the Tojiro on vegetables and wash & dry it after every use. Almost all mass produced or semi mass produced knives will vary a little on their heat treating and final finish. Getting a superb one is the luck of the draw; it seems that the Japanese take a little more pride and diligence in their craftsmanship than some.
Some of the knife forums are crazy with opinions of all sorts of knife metallurgy real and imagined; I’m glad this forum doesn’t stoop that low.
To me most Henckels seem soft like it is purposely heat treated not to chip or perhaps to have the edge roll so that users could take full advantage of steeling the blade; not my idea of ideal but some think they can’t cut anything without first picking up a steel and running it over the blade.
For the money, it is hard to beat Victorinox; the lower cost knives seem as good as their more expensive models, just not as fancy and they keep an edge at least as well as the Henckels. They are good knives to leave in a knife block on the counter when you have house guests or other help in the kitchen for when you have to hide your good knives.
I have a Tojiro Flash hook bladed peeler that came with a micro bevel on one side; the other side was polished. Whoever did the final hand finish may have been allowed to use their own method to obtain a good edge. I bought it about 4 years ago, I use it quite a lot and haven’t sharpened it yet.
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The type of steel and its hardness would be a factor in the longevity of the edge; a few light strokes with a file can tell a lot about the material you are trying to sharpen.
I have good friend that makes pizza for a private Italian club and I sharpen the pizza cutter for him in exchange for pizza. It is a big blade of fairly soft stainless about like the dollar store cheapo knives for hardness. I have discovered that a convex edge like you would put on an axe lasts the longest. It gets used a lot like an axe so I guess there are no surprises in my conclusion. I smooth the sides out with a buffing wheel and then add about a 30 degree final edge by hand with 400 diamond (wider than a micro bevel). This allows him to easily wipe off the blade if it gets a build up of cheese but it still has enough bite to grab onto other ingredients. My friend likes the result and I get a big fresh pizza for about 15 minutes work; win-win.
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I flipped the bar years ago and haven’t used the micro adjusters since. I have an allen wrench that fits the adjustment screw with a plastic screwdriver handle and sometimes use the handle to tap the adjuster along the bar. I have polished the end of the setscrew so that it doesn’t dig into the bar and mostly adjust with a pinching of the fingers action with one hand while controlling the friction with the other via the allen wrench. I find this to be much faster than the micro adjuster, but my OCD factor isn’t off the scale.
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Almost anything is interesting under a microscope. Besides what is listed above: hair, human and pet; dust; dryer lint; circuit boards form anything electronic; mold; flower petals; wood; the thin membrane of an onion is only one cell thick, a little food coloring may enhance it; you can buy sets of educational slides and kits of various slide dyes for more serious investigating. You can investigate the differences how inkjet printers, laser printers, ball point pens, crayons, pencils look on paper and compare them to paper money printing. Pretty soon you won’t get a chance to use the microscope yourself. But if it keeps them from the Xbox, it will be worth it.
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Yes, the Ram components are very versatile and easy to use for modding a WE.
Too bad all of the pictures from the older forum format have gone away as there were lots of good ideas there.
Here are some pictures of my aux support that I made a couple of years ago; you may remember the images from the old forum. The Ram ball also makes a handy stone stop and safety device when positioned near the point of a knife.
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