Flattening, polishing and friction.

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bugbear":1assqebb said:
Jacob":1assqebb said:
...I do think that flattening is usually achieved sufficiently every time you turn a chisel over to remove the burr -

Unless your stone were to have a hollow, in which case you're creating a convex back as well as a convex bevel. :lol: :lol: :lol:

BugBear

I've been thinking about this a bit recently and would a slightly concave arkansas/waterstone give the desired camber to a blade that we emulate with jigs, techniques?
 
wem":1lc2gi1q said:
bugbear":1lc2gi1q said:
Jacob":1lc2gi1q said:
...I do think that flattening is usually achieved sufficiently every time you turn a chisel over to remove the burr -

Unless your stone were to have a hollow, in which case you're creating a convex back as well as a convex bevel. :lol: :lol: :lol:

BugBear

I've been thinking about this a bit recently and would a slightly concave arkansas/waterstone give the desired camber to a blade that we emulate with jigs, techniques?
Certainly would. A nicely hollowed out stone can produce the camber you need really easily. I found this out when I once flattened a stone (experiment) and suddenly found sharpening got slightly more difficult. OK for chisels too - the shallow camber you have on plane blades works fine on a chisel though I imagine there are circumstances when you might want a dead straight edge, but I can't quite think what they would be.
 
Jacob, I actually have a situation in which it can be useful to have a flat bevel (none of this primary & secondary nonsense)... if you flip your chisel over and use it bevel down (I do this fairly often when tidying up stray fibers at the bottom internal corners of stopped rebates, mortices and the like) then being able to make the chisel ride on that flat makes it that little bit easier, I have a few narrow chisels which are sharpened nice and flat for that reason... For doing the work of a chisel (rather than an improvised router plane) it doesn't seem to matter what shape the bevel is, so long as there is one, it's not ridiculously steep and it ends in a sharp bit.
 
Jelly":1qrnl41p said:
Jacob, I actually have a situation in which it can be useful to have a flat bevel (none of this primary & secondary nonsense)... if you flip your chisel over and use it bevel down (I do this fairly often when tidying up stray fibers at the bottom internal corners of stopped rebates, mortices and the like) then being able to make the chisel ride on that flat makes it that little bit easier, I have a few narrow chisels which are sharpened nice and flat for that reason... For doing the work of a chisel (rather than an improvised router plane) it doesn't seem to matter what shape the bevel is, so long as there is one, it's not ridiculously steep and it ends in a sharp bit.

:D Yes Yes Yes. Really pleased you posted this. I have been trialing freehand instead of using the tormek and it's been fine. But as you pointed out I was cleaning a large recess and found that the chisel felt a little awkward when compared to the hollow grind of the tormek (and no my free hand is not a crazy convex). For some this might be fine and that's cool but as you point out it's not a positive as a flat bevel. I will be practicing the flattest bevel I can free hand. "the movement should be steady to avoid a rocking motion" Joinery & Carpentry Vol 1 1931 New Era Publishing "An undulating motion must be avoided as this will produce a round edge" Modern Practical Joinery, George Ellis 1902. Old knowledge is often the best :)
 
You can't avoid the rocking motion with freehand honing, in fact you will achieve far greater speed and consistency by going with nature and finding a comfortable flowing movement than you will by fighting it and trying to achieve a flat bevel. In 1902 they also believed that lefthandedness could be 'cured' by caning children and strapping their arm to their side...!

If you want flat primary and secondary bevels, these can be achieved very easily by using a honing guide.
 
matthewwh":9s3uebx1 said:
You can't avoid the rocking motion with freehand honing, in fact you will achieve far greater speed and consistency by going with nature and finding a comfortable flowing movement than you will by fighting it and trying to achieve a flat bevel. ........
Exactly what I have been saying for some time now!
It's fine as long as you dip rather than lift and round over the edge. Could be called "rounding under" - rounded bevel but edge stays at 30º. Fast, easy, precise.
If you want to you can achieve a reasonably flat single bevel freehand by being more careful (but slower).
 
Thanks Jacob. I have also been reading Krenov's books and he achieves a secondary bevel by relying on a concave grind from the wheel, this he rests on his stone and hones using small left to right or circular movements, nothing more, only the outer edges of the hollow grind contact. I have found this gives me much better results that last longer than any primary/secondary honing guide system. I suppose it is whatever works for you? Unfortunately it can be an expensive learning curve.

Edited because i meant concave.
 
I can't be the only woodworker out there who doesn't have a grinding wheel right? I don't get all of this "off the wheel" stuff, I've never come across a way to damage a chisel or plane iron (used properly) so badly that I couldn't get back to a decent edge with a coarse stone.

In fact I've probably only re-ground 3 chisels in all the time i've been woodworking (which actually belonged to work and were discovered being used as glorified tin openers), I moved the tool rest round to the side and used the flat side of the wheel to take the concavity out after taking the material off.
 
Jelly":24fi8804 said:
I can't be the only woodworker out there who doesn't have a grinding wheel right? I don't get all of this "off the wheel" stuff, I've never come across a way to damage a chisel or plane iron (used properly) so badly that I couldn't get back to a decent edge with a coarse stone.

In fact I've probably only re-ground 3 chisels in all the time i've been woodworking (which actually belonged to work and were discovered being used as glorified tin openers), I moved the tool rest round to the side and used the flat side of the wheel to take the concavity out after taking the material off.
Over the years I've wrecked a few chisels, usually on site - if a fine bevel edged parer is all you have in the box that's what you have to use (to get the lid off etc etc. :roll: ). It's only a fairly cheap tool and the job is usually worth a lt more.
So I've ground a few - never on a small wheel (too hot and too hollow ground) nor a large one (I haven't got one) but on a belt sander, lately up graded to a Sorby Proedge. On a flat stone only when there is absolutely no alternative.
 
Jacob":1sk12zoh said:
Over the years I've wrecked a few chisels, usually on site - if a fine bevel edged parer is all you have in the box that's what you have to use (to get the lid off etc etc. :roll: ). It's only a fairly cheap tool and the job is usually worth a lt more.

I can see how it happens to tools, but I still don't see how a grinder becomes part of a normal sharpening process... Rather than something that sits in the corner gathering dust for most of the time (the fact that you persisted with a belt sander for some time before getting a purpose built linisher illustrates that lack of use pretty well).
 
Jelly":1l6vzzhn said:
I can't be the only woodworker out there who doesn't have a grinding wheel right? I don't get all of this "off the wheel" stuff, I've never come across a way to damage a chisel or plane iron (used properly) so badly that I couldn't get back to a decent edge with a coarse stone.

In fact I've probably only re-ground 3 chisels in all the time i've been woodworking (which actually belonged to work and were discovered being used as glorified tin openers), I moved the tool rest round to the side and used the flat side of the wheel to take the concavity out after taking the material off.

Like Jacob said it depends on the work you do. If you are repairing joinery or working with reclaimed s'@! can happen!
 
In 1902 they also believed that lefthandedness could be 'cured' by caning children and strapping their arm to their side...! :D

If you want flat primary and secondary bevels, these can be achieved very easily by using a honing guide.[/quote]

Hi Matthew, I think honing guides are great for the reason you said. I guess I want to try an get a flat bevel free hand (without getting OCD) and I think it will come with practice. Wax on, Wax Off, Wax On, Wax Off.......................................
Also from a personal interest point of view an really enjoying the vibe of the old school stuff (corrective strapping aside :) ). It's a nice tonic to a busy day :wink:
 
1902? I was at secondary school (I am now 54) with a boy who was forced to change hands, he was at a private school at the time.

Pete
 
Jelly":18hm174i said:
I moved the tool rest round to the side and used the flat side of the wheel to take the concavity out after taking the material off.

Grinding on the side of the wheel is bad news. Unless the wheel is designed for it, which very few are.

If you really want a flat grind- http://www.ebay.co.uk/itm/Viceroy-Sharp ... 20c88fc357

Clocked a good few hours on one of those, messy bloody horrible thing...

JH
 
Hi, JH

I borrow the one at work for chipped plane and chisel blades, its a pain to use but takes the out hard work.

Pete
 
Racers":dudgvtqa said:
Hi, JH

I borrow the one at work for chipped plane and chisel blades, its a pain to use but takes the out hard work.

Pete

They are good, just not so keen on the oil!

JH
 
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