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Sharpening rabbit hole https://luthiersforum.com/forum/viewtopic.php?f=10101&t=56250 |
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Author: | truckjohn [ Fri Feb 02, 2024 10:39 am ] |
Post subject: | Re: Sharpening rabbit hole |
I didn't use to polish the back - just flattened it. I did some testing and found that lightly buffing the back at the very tip made the edge last longer, so now I do. I don't intentionally mirror it, though. |
Author: | Dave m2 [ Fri Feb 02, 2024 11:06 am ] |
Post subject: | Re: Sharpening rabbit hole |
Brad polishing the back is absolutely part of the sharpening process. If you think of the chisel edge it is actually the meeting of two surfaces, the bevel that you have just formed and the back of the chisel. If the back is at all rough then this edge is going to be ragged. For plane blades David Charlesworth who was the UK guru on sharpening had a great trick. Rather than polishing the whole of the back of the iron, in the last stages of sharpening he suggested putting a 6 inch steel rule on the edge of the stone, creating a tiny bevel on the back which could be made very smooth. If you work through the geometry it is a very small angle so does not change the geometry of the cutting edge much. Cheers Dave |
Author: | doncaparker [ Fri Feb 02, 2024 11:33 am ] |
Post subject: | Re: Sharpening rabbit hole |
truckjohn wrote: I didn't use to polish the back - just flattened it. I did some testing and found that lightly buffing the back at the very tip made the edge last longer, so now I do. I don't intentionally mirror it, though. Another small comment from me about buffing: I can sharpen/polish to a really high grit, and no matter how high I go with the sharpening/polishing, I always get a sharper edge if I follow that with a few seconds on the buffing wheel. I've done before and after tests with my chisels and plane irons, and it is consistently true for me. Buffing gives me a sharper, smoother edge. So, I would do it even if I didn't want to use the mirror trick from time to time. As always, YMMV. |
Author: | James Orr [ Fri Feb 02, 2024 11:47 am ] |
Post subject: | Sharpening rabbit hole |
I've tried just about every *type* of method as well (Worksharp, scary sharp, stones, freehand, the double-bevel setup in Ervin's books, etc). I've finally settled on a basic jig I made about ten years ago for setting blade angle and a Lie-Nielsen honing guide. I don't think there's a best approach, but this has been the best approach for me. I use a DMT C/XC DuoSharp for repairing edges or changing bevel angle, but typically just touch up on 1000 followed by 8000. 20 or so strokes on each. 10 works. 20 is generous and only takes another 10 seconds. It takes under a minute to touch up a blade moving comfortably, not including the time it takes to wet the stones or dress them afterwards. I use the ruler trick with plane blades by not chisels. If you're just paring with the chisel, it won't matter. I use mine for dovetail work as well, and it makes a difference there. I'm re-designing my workbench (again) and plan to have a small, shallow drawer just under the worksurface for the jig so it's always quickly at hand. I'll take a pic of the jig when I get home. Woodpeckers has a great looking new honing guide, but I can't justify grabbing it just to have fun. |
Author: | Dave m2 [ Sat Feb 03, 2024 11:57 am ] |
Post subject: | Re: Sharpening rabbit hole |
+ 1 for the LN honing guide. It is expensive but the clincher for me are the jaws for honing skew chisels. I use them a lot in the carving of the heel. Dave |
Author: | Eric Reid [ Sat Feb 03, 2024 8:33 pm ] |
Post subject: | Re: Sharpening rabbit hole |
Colin North wrote: And I've found out something from my dive into this. My DMT XXF, supposedly 8000 grit seems to have lost nearly all of of its diamonds. After 10/11 years of use I have been honing on a steel plate. The rogue scratches in the pis seem to have come from the scratches in that plate, NOT from some odd larger diamond particles or contamination as I thought, so I've got a new stone coming to fit into my sharpening sequence. And I'll put in a good word for the DMT DiaFlat 95 micron to flatten water stones. Expensive, but it seems to be everything they claim. Mine is anyway. This article is interesting (and confounding) regarding DMT stones. https://scienceofsharp.com/2015/03/01/t ... ogression/ This also. https://scienceofsharp.com/2016/12/21/a ... e-vs-grit/ |
Author: | Kbore [ Sat Feb 03, 2024 9:49 pm ] |
Post subject: | Re: Sharpening rabbit hole |
Eric Reid wrote: Colin North wrote: And I've found out something from my dive into this. My DMT XXF, supposedly 8000 grit seems to have lost nearly all of of its diamonds. After 10/11 years of use I have been honing on a steel plate. The rogue scratches in the pis seem to have come from the scratches in that plate, NOT from some odd larger diamond particles or contamination as I thought, so I've got a new stone coming to fit into my sharpening sequence. And I'll put in a good word for the DMT DiaFlat 95 micron to flatten water stones. Expensive, but it seems to be everything they claim. Mine is anyway. This article is interesting (and confounding) regarding DMT stones. https://scienceofsharp.com/2015/03/01/t ... ogression/ This also. https://scienceofsharp.com/2016/12/21/a ... e-vs-grit/ Those articles (companions) were very intriguing. It took a while for me to get the photo's orientation (as in holding sharp end up, looking down the sharpened edge from the side, at an oblique angle). I bought a drill press sharpening "system" from Taylor Tools last year for grinding damaged edges. With 2 grits (80 and 220; 3M Cubitron II Sanding discs) and a circular leather strop, charged with white metal cutting compound, I "re-ground" and sharpened a chipped chisel cutting edge, using the drill press, to hair shaving sharpness in two minutes. You have to make your own tool holder which was a pretty good challenge to get flat and square with the spindle CL, but very doable. Off the sharpener, that edge not only shaved arm hair, but sliced through hardwood endgrain without a problem. I bought the system for repairing damaged edges since I don't have a Tormek, or the patience/ fortitude to do it by hand. I was absolutely amazed. I was prepared to finish the edge with the Veritas MK II and several iterations of diamond stone. It was absolutely not necessary as the two grits + stropping produced a razor edge for shaving wood (and arm hair). Veritas has a similar I'm not endorsing or recommending, just sharing my positive experience. More detailed information: https://taytools.com/products/drill-pre ... 61a0&_ss=r I would love to see that edge under Colin's microscope. |
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