Tutorial Razor Honing Part 1

Discussion in 'Tutorials' started by Steve56, Jul 19, 2018.

  1. Steve56

    Steve56 Well-Known Member

    IMG_1160.JPG Honing

    Razor honing is pressure management.

    Keep a honing journal describing how you honed difficult razors, or of the issues with particular razor helps. Definitely keep a journal of razors honed for other people and for the unusual razors in your collection.

    Workplaces

    Your workspace should be maintained clean and free of any objects that are not actively being used that could create bumping hazards for your hands and the razor. Bumping the razor sometimes happens to us all, bumping the razor against something that does not have to be there is well, entirely avoidable. Don’t allow grit, dust, dry slurry, etc to accumulate in your honing space. In other words clean up after a honing session. A simple wipe with a wet cloth works well.

    Observing the Bevel

    You want to look at the bevel for reasons described below. What you use is up to your eyes and brains, but 7x is good for me, 10x at the most. Why not 100x or 1000x? I recently got a message from a friend and he said ‘My edges are better if I don’t use microscope’. I think microscopes have their uses like comparing scratch patterns from different stones but I doubt using one will actually get you a better edge.

    Inspecting the Victim

    Straight razors are for the most part handmade and hand honed. Every one is different. It helps immensely to know what you’re up against before you put steel to stone. I cannot know what everyone’s razor is like, so I am going to describe an elaborate process for first time honing a razor, but you can pick and choose parts of this process as you like for razors that you ‘know’. It’s a process that I might use the entirety of when honing a valuable used razor with wear on it, like someone’s family razor.

    First, I just visually inspect the razor edge with a bright light. I’m looking for frowns and smiles, heel hooks, chips, badly formed toes and heels, and so on.

    Next, I look at the spine of the razor like looking down on the spine against a bright uniform background. I’m looking for warps, curves, ’S’ shapes, and any other shapes that aren’t supposed to be there.

    A common problem is a tapered spine on old razors, caused by pulling the heel off the hone or otherwise not spending the same amount of time on all parts of the edge over decades. The spine is thicker over the heel that at the middle or toe. Image above, you don't need calipers to see the tapered spine on this W&B. It’s helpful to actually take dial calipers and measure the spine thickness over the heel, middle, and toe. You will be unpleasantly surprised by many vintage razors. What this means is that you can’t hone a razor with a tapered spine at different angles to the stone while honing or you’ll cut different bevels depending on how much of the thicker spine that you have on the hone. Worn toes caused by barbers improperly using a pigtail stroke is also a good example.

    BTW, a ‘hollow’ tapered spine is called a differential taper and is a sign of a very high end knife because it reduces the blade weight. Knives are honed with the spine off the hone, so the spine doesn’t determine the bevel angle.

    Setting a Bevel

    The end result of bevel setting is to have both bevel planes meet with no defects along the apex of the bevel, the cutting edge. This is not always as easy as it sounds because of razor geometry. It really doesn’t matter at what grit you set the bevel, I frequently re-set them at 4-5k.

    It’s also helpful to Sharpie both the bevel and spine then do one or two light passes and see where the marker has worn. This will show some razor problems and also if you’re not biasing pressure enough to hit all the bevel. Obviously, if you’re using tape on the spine it doesn’t make much sense to Sharpie the tape.

    There are a number of tests that you can use to determine if the bevel is set. It doesn’t matter which one you use as long as you practice enough to interpret the results. But you do need to not be guessing about whether the bevel is set or not. Here are some examples.

    Observation
    Burr method
    Thumbnail test (TNT)
    Thumb pad test (TPT)
    Hanging hair test (HHT)
    Tree topping

    One of the simplest is to simply look at it with some magnification under a bright light. I like to get the light reflecting strongly off the machined areas at the toe and heel then rotate the razor so the light will reflect off any problem areas at the apex. There should be no shineys, sparklies, bright lines, etc, in other words, at up to 10x magnification you should not be able to see anything at all on the apex of the bevel.

    The burr method is an exception. This is a technique used by knife honers who will use high pressure to raise what amounts to a folded over ‘ribbon’ at the apex, and if you do this on both sides all along the bevel, the bevel is set. The burr is raised by honing on one side of the blade with good pressure and inspecting the edge, you can both see and feel a burr. The burr will also shine or sparkle under good light, and the lesson to be learned is that not everything that sparkles on the apex is an unset bevel, though most sparklies mean that, or a chip. Most beginners use too much pressure and a burr can easily form. Then you have to hone the burr off by using very light pressure, flipping the blade over each stroke until it is gone. I don’t like the burr method as it seems to put more wear on the razor then the burr has to be removed by further honing.

    Both the thumbnail test and the thumb pad test depend on the razor biting or catching when it contacts the nail or skin. If it skates across the nail or doesn’t want to ‘dig in’ to skin (be careful of course), the bevel is not set. The thumbnail test is somewhat destructive so after it passes a few touchup strokes are usually in order.

    Tree topping is moving the razor above usually the arm or leg to see if the razor will cut hair when not in contact with the skin. If it does so all along the edge the bevel is set. It’s basically a root-in hanging hair test. The hanging hair test uses hair that isn’t attached to you, you hold a hair in your fingers and simply see if the razor will cut it. I like the HHT but many people don’t. The upside is that a razor’s only purpose is to cut hair, and if it does cut at say 4-5k, all along the edge, the bevel is perfectly set. If it won’t cut hair at 5k, I can re-iterate a saying of the Navy nukes, ‘believe your indicators’. Another advantage of HHT is that a hair is so small you can easily test the last millimeter of the edge. The HHT is easier to perform root out than root in because of the way the surface of hair grows.

    The way I test for a set bevel is by visual inspection at 2k or whatever grit I use to begin with, then at 4-5k, I do a ‘half stropping’ 10 canvas 20 leather and use the HHT. If it cuts hair easily and the same toe, center, and heel, the bevel is set.


    Common problems during bevel setting


    Too much pressure
    Uneven pressure
    Mistaking a burr for an unset bevel
    Not hitting all the edge from ‘bad’ pressure bias

    One of the issues with videos is that they cannot show you how much pressure to apply, or how to bias pressure during the stroke. If you use too much pressure, you will raise a burr or worse, flex a hollow ground razor enough for the stone to scratch the side of the blade. They’re that thin. Image below of a once pristine Filly 14 that someone turned into a user-grade razor worth maybe half of what it was before he started. Note the scratches above the bevel. They've pushed so hard the blade deflected and the hone was hitting the side of the blade. This turned a $500 razor into a $200 razor. This is an old eBay image. (Credit Edit: this is an old image from SRP, I have another from eBay)

    Pressure bias, that is applying pressure evenly to the heel, center, and toe is a learned skill. The amount of pressure needed can be learned once, pressure bias has to be learned for each blade because almost none of them are the same shape as any other. While you’re learning, inspect the bevel striae at each grit to ensure the last stone’s striae are removed heel, center, and toe, and the entire bevel has the same finish.

    Mentoring is the best way to learn both of these, so if you can come up with an experienced person close by, you’re miles ahead. Almost everyone, including me destroys one razor and puts too much wear on several others learning how much pressure is needed. A local fellow who lives about 30 miles away is an experienced knife and broadhead honer took up razors. In trying to set a razor bevel, he posted images on a popular forum of bright lines along the apex. He was told that the bevel wasn’t set, keep going - and he did for a few hours a day for a week or more! He finally took me up on my offer to come up and help, and the problem was a burr, not an unset bevel. As soon as I showed him that he could feel the burr, the light came on, his bevel was set a week ago. You can also get mentored by mail if no one’s close, an experienced honer can tell you a lot by looking at a bevel.

    Not hitting all the edge is pretty common even for experienced honers. There are a couple of things that can help. When you’re honing, watch for the water wave ahead of the edge. Ideally, it should climb up onto the blade, and it means that the apex is in contact with the hone. However, if your work surface is tilted enough that water runs to one side of the hone, the other side may not show much of a wave. Also if there’s any oil, wax, or polish on the metal the water may not run up the blade.

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    Last edited: Jul 19, 2018
    BearCWY, PLANofMAN, Paul76 and 5 others like this.

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