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By Jacob
#677438
matthewwh wrote:.....
I never thought I'd be arguing in favour of freehanding a rounded bevel........
Glad to hear you are getting there, albeit slowly!
It's only a few woodworkers who have this modern phobia about rounded bevels. They were normal - and still are in many other areas of sharpening.
I think the phobia is a good example of the "viral" dissemination of misinformation.
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By shim20
#677447
i sharpen free hand, way i was tort and its the way it was done years ago, i do it little and often only takes a little time that way, i often just buzz over on a medium then fine oilstone. i tried waterstones but at work i found them to messy, as for strops i do have a bit of leather on a block but most the time i don't use it, my 2ps worth :lol:
By woodbrains
#677522
Hi,

Putting a tiny (rounded or not) microbevel at the tip of the cutting tool to eek a little more working time out of a tool before re sharpening, is something we all probably do from time to time. This is not the same as the total bunkam of rounding under, that Jacob continuously prattles on about. Let us face it, the Fine India stone which appears to be his staple, has a grit size of 42 microns. I don't think any reasonable person would even consider that sharp enough for anything finer than an axe. And how anyone can say with any amount of seriousness that a sharper edge just dulls quicker anyway--words fail me I have to say. It is pityful we have to put up with such twaddle.

I don't think stropping is of much use to those who sharpen with waterstones to a fine enough grit or those who use 3M lapping film. Oilstones don't get any finer than about 9 micron (surgical Arkansas) so stropping after these would definitely give a better edge.

I don't buy into the idea that stropping on a cushioned substrate (leather) gives the paste a softer effect, either. 0.5micron chrome oxide is 0.5 micron no matter what it has been coated on to. The idea of the leather is to create a micro bevel so it doesn't take so long to actually achieve a polish with such a fine, cutting abrasive.

Mike.
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By Jacob
#677540
woodbrains wrote:H.....This is not the same as the total bunkam of rounding under, that Jacob continuously prattles on about.
If you, or anybody else, could explain why "rounding under" is bunkum, I could stop prattling on about it it. But you can't, and neither can anybody else.
Let us face it, the Fine India stone which appears to be his staple, has a grit size of 42 microns
. 1200grit (whatever that means) according to DC see above, but I do go finer if I need to
I don't think any reasonable person would even consider that sharp enough for anything finer than an axe. And how anyone can say with any amount of seriousness that a sharper edge just dulls quicker anyway--words fail me I have to say. It is pityful we have to put up with such twaddle.
Twaddle yourself. Not exactly "dulls quicker", more loses it's uber sharpeness quickly and becomes averagely sharp, which deteriorates more slowly. Thats why if you want to keep a very sharp edge sharp you have to strop very frequently, as everybody knows, except you perhaps.
It might help with these threads if they were labelled either "hobby/enthusiast sharpening" or "sharpening for woodworkers". Several people pointed out in an earlier thread that sharpening is a hobby in it's own right, which creates crossed lines!
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By Karl
#677542
I think these last two posts demonstrate something fundamental here.

How sharp is sharp enough?

To an extent I agree with Jacob in that as long as the edge does the job, it is sharp enough. I have spent plenty of time putting an extreme edge on blades (particularly for wooden planes), and then losing some of that "ultimate" edge in setting up the plane and taking test cuts! If you're working a plane hard it may need re-sharpening after 10/15 mins anyway, and putting a super-sharp 0.3grit edge on the blade doesn't make any difference to the work in hand. With the exception of smoothing planes, where I tend to go the extra mile as the blade is only used for a few swipes in any event.

For general work, if it shaves the hair on my arm, it's sharp enough - regardless of what the grit says.

Cheers

Karl
By Cheshirechappie
#677586
Something the experimenters might like to investigate is the lasting quality of edges sharpened in different ways. For example, with modern equipment such as diamond lapping films it appears possible to achieve almost insanely sharp edges, but how much service will such an edge give before breaking down? What's the optimum level of sharpness that gives good results with minimum time spent maintaining the edge, and maximum time cutting wood, on different duties?

Karl's point about how sharp an edge needs to be for different tasks seems to me the key point. For example, there seems little milage in sharpening and honing a mortice chisel to the sort of edge angles and sharpness normal for a finish carving tool, as the edge would break down almost at the first whack of the mallet.

In the 18th and 19th centuries, when the only sharpening stones readily available were the likes of Turkey, Charnley Forest and Welsh Slate, stropping on dressed leather (which was fairly cheaply and easily available) was a realistic way of quickly refining an edge. (I've never tried this, but I think you can strop an edge on the palm of your hand; seem to remember this written in one of Charles Hayward's many books.) Now that the technology of sharpening has developed, it would be surprising if no better method of achieving a very fine edge than stropping had been developed. However, that doesn't mean that stropping is dead - it quite plainly worked very well for many craftsmen over several generations, and much fine work was done by them to prove the point; so it will still work just as well.
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By Paul Chapman
#677611
Cheshirechappie wrote:Karl's point about how sharp an edge needs to be for different tasks seems to me the key point.


But it's not just about sharpness. Very often it's about matching your tools and techniques to the wood. I was planing lots of Sapele today. It was horrible stuff with all the usual reversing grain. No matter what I did I couldn't get a decent finish with my normal planes - just lots of tearout and general roughness. So I got out my scraper planes (the large Veritas and small LN #212) and had a silky smooth finish in no time :D

Cheers :wink:

Paul
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By Jacob
#677648
David C wrote:Jacob,

I was being kind and assuming that you might have something like a hard Arkansas stone.

David
I have a black "surgical" Arkansas stone. It's too fine for woodwork purposes. Probably why it's termed "surgical".
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By Jacob
#677650
Paul Chapman wrote:
Cheshirechappie wrote:Karl's point about how sharp an edge needs to be for different tasks seems to me the key point.


But it's not just about sharpness. Very often it's about matching your tools and techniques to the wood. I was planing lots of Sapele today. It was horrible stuff with all the usual reversing grain. No matter what I did I couldn't get a decent finish with my normal planes - just lots of tearout and general roughness. So I got out my scraper planes (the large Veritas and small LN #212) and had a silky smooth finish in no time :D

Cheers :wink:

Paul

It's sapele which set me off on the perfect planing hunt. It's not hard all over, quite the opposite in parts, and very crossed reversing grain. Some parts impossible to plane even with my LV la smoother. OK it might have been possible if I'd spent several hours crazy sharpening and then repeating between strokes, but I gave up and bought a Bosch ROS.
My planing did improve a lot during the exercise so it wasn't an entire waste of time.
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By Derek Cohen (Perth, Oz)
#677691
Hi Jacob

I know that you are a professional woodworker and I am a mere amateur .... actually it is because you are a professional woodworker .... that I really struggle to grasp why you want to work with chisels that are not hair-popping sharp (don't take that literally, you know what I mean). The danger of crushing timber fibres rather than severing them cleanly is an ever-present risk. Why would you wish to put yourself in this situation?

Note that despite my hobbiest status as a woodworker, I am not a sharpening hobbiest. I just pay attention to sharpening issues and own decent sharpening media. Perhaps I am too naive to think and work like a professional.

In my experience there is a world of difference in paring, for example, endgrain with a sharp edge, especially in either softwoods or very hardwoods. Dull edges are dangerous as you are required to use more force than necessary. "Sharp enough" in my book is VERY sharp. I cannot get that off a 2000 grit whatever (waterstone equivalent). At least 8000 grit is my target (I generally go to 12000). This usually only requires a 1000 and 12000 stone to achieve this level, and a couple of minutes at most. In terms of time and effort I just do not see what the fuss is about.

Just what do you consider "sharp enough" to be? And how do you determine this in the work you do?

Regards from Perth

Derek
By St.J
#677698
Dear all,
I've been lurking here a long time, what a great resource.
It's a bit sad that the first time I've felt able to offer something the thread is about sharpening...

Those interested in the different merits of green rouges (is that an oxymoron?) will enjoy this fabulously geeky post about the granularity of Lee Valley compound: (at this point I tried to post a link but my account won't allow it so try the google search term "lee valley rouge micron consumer alert" and it's the top hit.

I use a hollow grind on most of my edges and then work my way down through three Arkansas oilstones. Because I sharpen freehand this takes very little time and while working I rarely go back to the coarsest stone.
I rarely strop my woodworking tools: plane irons, chisels etc. but do strop my carving tools.

I have two leather strops, one with Boron Carbide paste (1 micron?), the other with Chromium Oxide (0.5?). If the light is angled correctly the surface of the first strop appears shiny. When I take the first stroke it goes black. - dull and perhaps rougher. I believe that this is the very fine wire edge created by the finest Arkansas stone coming off. The next few strokes make the strop go shiny again.

I don't strop my carving tools because it makes them sharper (it might, but after a couple of minutes use who can tell?). I do it because it polishes the bevel and makes them less grippy, easier to push through the wood. And because Chris Pye tells me to :wink:

In short - stropping makes my paring tools seem sharper because they're polished. And it removes the wire edge. I think.

St.John
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By Jacob
#677744
Derek Cohen (Perth, Oz) wrote:.........
Just what do you consider "sharp enough" to be? And how do you determine this in the work you do?

Regards from Perth

Derek
It's a question of striking a happy medium between time and effort spent sharpening and the requirements of the job in hand.
If the job particularly requires very sharp edges (clean finishing cuts) then frequent honing on finer stones may be required. Or not, as the case may be - hacking out a mortice and you can go a lot longer between honings. The limit then isn't the finish quality but the force required to make the cut.
In other words - it's perfectly self evident isn't it? Why am I having to spell it out? :lol:
Last edited by Jacob on 15 Apr 2012, 14:01, edited 2 times in total.
User avatar
By Paul Chapman
#677795
Jacob wrote:
Paul Chapman wrote:
Cheshirechappie wrote:Karl's point about how sharp an edge needs to be for different tasks seems to me the key point.


But it's not just about sharpness. Very often it's about matching your tools and techniques to the wood. I was planing lots of Sapele today. It was horrible stuff with all the usual reversing grain. No matter what I did I couldn't get a decent finish with my normal planes - just lots of tearout and general roughness. So I got out my scraper planes (the large Veritas and small LN #212) and had a silky smooth finish in no time :D

Cheers :wink:

Paul

It's sapele which set me off on the perfect planing hunt. It's not hard all over, quite the opposite in parts, and very crossed reversing grain. Some parts impossible to plane even with my LV la smoother. OK it might have been possible if I'd spent several hours crazy sharpening and then repeating between strokes, but I gave up and bought a Bosch ROS.


You should have tried a scraper plane, Jacob. No need for any crazy sharpening :wink: I've yet to find a piece of wood with difficult grain that can't be tamed with a scraper.

Cheers :wink:

Paul