Trip Posted September 18, 2015 Report Share Posted September 18, 2015 (edited) ==>One perspective. Based on the reference to FWW and the date of the thread ('08), I suspect the thread is referencing HV's article... He's (along with the rest of the FWW crew) a strong advocates of hollow ground primary bevels... But the thread takes HV's prospective a bit further than he intended -- sort of like folks using the ruler trick on BU irons... Also, the folks who advocate hollow-ground primary bevels may or may not advocate secondary bevels, or if they do, then many advocate that they should be established on a stone (this happens to be my practice).I've posted my thoughts on hollow-grinding several times here and on LJ, so I won't repeat them... I hollow grind most of my edges, but not all... There are places where it is clearly not appropriate -- and I believe HV covers those cases in his original article... The issue frequently glossed-over is that all hollow-grinds are not the same ---- the size of the hollow makes a big difference -- HV (and the FWW staff) are assuming 8"-10" wheels (read as Tormek). Once you get to a steeper hollow, edge breakdown becomes more of an issue and it's utility diminishes... Species, edge size, metallurgy, and intended use also come into play -- again, I believe HV covers those cases... A big D2 mortise chisel whacked into Hard Maple is a different animal than an 1/8" O1 dovetail paring chisel pushed into Mahogany. If you want way more on this than you'd ever need to know, check-out Ron Hock's Sharpening Blog...https://hocktools.wordpress.com/There, you'll discover the 'why'... Edited September 18, 2015 by hhh 2 Quote Link to comment Share on other sites More sharing options...
Eric. Posted September 18, 2015 Report Share Posted September 18, 2015 I might get beat up for this by the sharpening zealots...but I think everything in here is over-complicating a fairly simple task. Like Tom, I just freehand mine. I don't use the ruler trick to flatten the bottom...it's such a small amount of metal that it takes no time at all. Then I hone the bevel freehand too. I don't go back and forth...just back, at a diagonal. And I don't create a secondary bevel so the risk of rounding over the edge is minimal.All these jigs and hollow grinds and complications...eh, not for me. My blades are plenty sharp without them. I do the same for my marking knives...a couple careful, steady swipes and you're back in business. Chisels and plane blades, different story. I jig up for those. Quote Link to comment Share on other sites More sharing options...
Tom King Posted September 18, 2015 Report Share Posted September 18, 2015 I hollow grind most things, but see no need for such a small surface area as a router plane cutter. with one finger on the back of the cutter, you can feel when it's flat on the stone, and it's easy to keep it that way. Quote Link to comment Share on other sites More sharing options...
Trip Posted September 18, 2015 Report Share Posted September 18, 2015 ==>easy to keep it that wayAhhhh, the crux of the issue... It's easy for those with experience, muscle memory and rapidity... Then there are the rest of us who view sharpening on the same plane as a trip to the dentist.... I don't have the muscle memory to sharpen effectively free hand. I can do it... I can sometimes do it well... If I'm in a hurry, I'll touch-up free hand... But a jig is my go-to... Sort of like training wheels... Quote Link to comment Share on other sites More sharing options...
Immortan D Posted September 18, 2015 Author Report Share Posted September 18, 2015 I have no skills... I need jigs for everything LOL Quote Link to comment Share on other sites More sharing options...
derekcohen Posted September 18, 2015 Report Share Posted September 18, 2015 One advantage of hollow grind is you do less work fine honing, because the grinding removes extra stock in the middle. Then you only have to wear away the very edge and back lip of the bevel on your slower cutting fine grit abrasive devices of choice, rather than the entire surface of the bevel.Very well stated!A hollow grind is self-jigging if you want to freehand sharpen, that is, the two sides of the hollow act as a jig to balance the bevel. It minimises the likelihood of rocking the bevel face and honing out-of-square. Whether freehand- or guide sharpening, it reduces the amount of steel to remove, which means faster sharpening.This hollow ground chisel required just a few strokes on stones to hone, and it will likewise require a few strokes to re-hone. This makes sharpening - and re-sharpening - a very easy and quick process (under 60 seconds) ...The importance of the hollow grind is one reason I spent time perfecting this on plane blades as well on the router plane blade. The earlier link provides information on the router plane. The following link was mentioned in a previous discussion on sharpening (this is provided as an illustration of where I am at, but not as a recommendation of what others should do): http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp.htmlRegards from PerthDerek Quote Link to comment Share on other sites More sharing options...
Immortan D Posted September 18, 2015 Author Report Share Posted September 18, 2015 Getting consistent shavings now: Quote Link to comment Share on other sites More sharing options...
Vyrolan Posted September 18, 2015 Report Share Posted September 18, 2015 Getting consistent shavings now:Whoa whoa whoa...actual woodworking? I didn't know that was allowed around here...thought we were just supposed to bounce around between discussions about how to sharpen and which table saw to buy? Quote Link to comment Share on other sites More sharing options...
Coop Posted September 18, 2015 Report Share Posted September 18, 2015 Nice job Daniel. Which route did you go to sharpen it? Quote Link to comment Share on other sites More sharing options...
Immortan D Posted September 18, 2015 Author Report Share Posted September 18, 2015 I built a jig and also used the ruler to clean the flat side: The Armstrong holder worked out very well, a few pics:I used a piece of wood for support, to help holding the angle. That part needs some improvement if I'm going to do this often. Whoa whoa whoa...actual woodworking? I didn't know that was allowed around here...thought we were just supposed to bounce around between discussions about how to sharpen and which table saw to buy?LOL that was a test piece not actual woodworking Quote Link to comment Share on other sites More sharing options...
Coop Posted September 18, 2015 Report Share Posted September 18, 2015 Crap, I remember seeing the pics now, before I high jacked it about the hollow grind. Sorry. 1 Quote Link to comment Share on other sites More sharing options...
Immortan D Posted September 19, 2015 Author Report Share Posted September 19, 2015 Another test cut, for Vyrolan. 1 Quote Link to comment Share on other sites More sharing options...
Coop Posted September 19, 2015 Report Share Posted September 19, 2015 Cool! 1 Quote Link to comment Share on other sites More sharing options...
Vyrolan Posted September 19, 2015 Report Share Posted September 19, 2015 Keep testing until you have to sharpen again so you get more sharpening practice. =p 1 Quote Link to comment Share on other sites More sharing options...
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