Are you guys this nuts, or is it me? Angles and burrs
- This topic has 19 replies, 6 voices, and was last updated 04/04/2019 at 3:32 am by
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I never liked the VTSA’s. They didn’t work so great for me either. I took them off my Gen 3 vise. I checked after each grit change. I now use the Gen3 Pro, so there is no VTSA, i still check after each grit. I sometimes sharpie during the progression, then check with USB scope jchange.ust to make sure im apexing. After first burr i don’t raise a burr each grit
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Ditto what Pinkfloyd said. I never found the the VTSAs effective. Especially now with better toleranced guide rods and stones, and more precise 3 axis digital cubes, (dxl360s), there are no reasons not to check and micro-adjust with each grit change, to take full advantage of the improved precision.
I visually monitor my progress with a USB microscope so I can see when my scratch patterns are apexing the knife edge. I don’t need to go so far as to intentionally create the burr to indicate I have apexed the edge. The slight burr I do always feel is a result of executing proper technique and the indicator that the edge was truly apexed.
Marc
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Thank you so much for the replies.
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I used the VSTAs successfully for a long time and never had a problem, once I developed a routine. I was using home-made handles, so I had to deal with the fact that my bore axes were never equidistant to the the opposite sides of the stones.
To determine if you need to check the angles and/or to use the VSTAs, go through your sequence of grits, measuring each as accurately as you can and recording the results. Not having done this in quite a while, I noticed a problem earlier this week with one of my 200/400 stones. The 400 side was leaving scratches at the bottom of the bevel, so it was clearly different from the 200 side. An angle check showed about 0.25 degrees difference.
If you find that all of your stones measured to be within some window – for instance, ranging from -0.1 to +0.1 degrees, you really shouldn’t need to measure once you’ve made the initial angle set-up.
The most important issue to be aware of is whether or not you’ve reached an apex along the entire length of the edge. Thereafter, I consider visual inspection between grits to be critical. It’s here that you’ll notice any angular error – the scratches from the previous grits are still apparent either at the apex or at the bevel shoulder, suggesting that your current stones is working at a different angle. You ought to be able to see this easily by inspecting the bevels with a loupe, although I think a hand-held USB microscope is vastly easier to work with.
I find that using the burr as an indicator of working the apex works best where you stone one side at time. I think alternating strokes tend to knock off the main burr. Any remaining burr would be the product of a single stroke and very hard to detect. To exacerbate this shortfall, finer grits produce even smaller burrs.
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phillyjudge: the stropping process is more flexible then the sharpening process. We back off the strop angle 2 degrees or so to avoid rounding off the edge. Some of us have found 1.5 degrees works best for us. Others use 2 degrees and still, others may use only 1 degrees. My point it is that it’s subjective and influenced by technique. There is flexibility with stropping and the process is about the smoothing and polishing from the burnishing effect. Not angle setting as seen in the sharpening steps. So precision in setting stropping angles isn’t necessary. Being off a few 10th doesn’t seem to make a difference when stropping.
Marc
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MarcH: brilliant, thank you. Is the idea to reach the apex then, or just burnish the bevel leading up to it? I don’t like my edges too polished, I like a degree of tooth. I usually stop at 1000 or 1500. If I get carried away, I use the DLF…I did do a Hogue folder with mirror bevels and a 600 edge and it is a frightening all around-er.
How is stropping any different than DLF, don’t they accomplish the same thing, just different ways?
PhillyJudge, the other things I see that the strop does different (I still am learning how to use them) is it polishes the base of the bevel where it end, rounding it off like a chamfer. This let the item you are cutting slide though as there is no longer the sharp angle a the bottom of the bevel. This can be seen with a loop or usb microscope.
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Stropping not only polishes the bevels but it also increases sharpness. I can personally attest to the fact that knives which would not whittle hair before stropping were able to do so after stropping.
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I don’t even see the VSTA’s (got the name right this time) listed on the website anymore
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For me the DLFs are to smooth and polish the bevel to be mirror reflective. Since the two smoothed bevel sides intersect at the knife edge, the knife edge may become narrower, too.
The strops I use to refine and smooth the cutting edge and add just that extra bit of sharpness. By refine, I mean smooth out the rough, draggy or edge catching felt while cutting substrates. This is particularly noticeable slicing paper. At the same time the strops do polish the bevels, also.
I strop every knife I sharpen as the last step.
Marc
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