Sharpening angles - thanks!
s_ribs
I was just about to head back to Woodcraft very ticked off at their
Pinnacle A2 blade edge retention, and then I remembered your site.
I'm only 6 months into the woodworking hobby, but I have been proud of
my attention to sharpening. So, I was exceptionally frustrated at the
edge disintegrating within a few minutes! Thankfully I questioned
myself and wondered if I was missing something...
Sure enough, I was.
I read through all of the pages once again and realized that while A2
is longer lasting than O1, it is more fragile than others like D2.
Pulled out the angle gauge and realized that my secondary bevel was
only 27 degrees! I created a tertiary bevel at 31 degrees, added a 2
degree micro back bevel. Boy was I a happy camper!! Immediately had
effortless, full width light shavings in some obnoxious grained walnut
(and no mangled edge). When you get it right, there is nothing like a
properly sharpened edge.
This is in my old Stanley No. 5 (type 16) for whatever curiosity there
is.
This post is simply to say thanks for your research and taking the
time to post your findings online to help guys like me out.
Seth
Bill G
I am curious, how do you achieve the back bevel?
I wish there was a single jig that enabled you to mount a plane blade, and simply sharpen,
then flip over, and work the back bevel.... how do you work the back bevel, with the
ruler trick?
Bill
Seth Ribbens
-- Seth J Ribbens
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Brent Beach
On 20/05/2011 8:58 AM, Bill G wrote:
> Hi Seth, thx for sharing your experiences....
> I am curious, how do you achieve the back bevel?
>
> I wish there was a single jig that enabled you to mount a plane blade,
> and simply sharpen, then flip over, and work the back bevel.... how do
> you work the back bevel, with the ruler trick?
Funny you should ask that question on this group!
Google 'brent beach sharpening jig'!
Brent
--
Victoria, B.C., Canada
Bill G
my problem is, i am addicted to my Shapton ceramic stones, I sharpen up to the 30k stone...
so I like the wheel for rolling on the surface of the stones...
so I wanted a way to flip the blade over, just like you do, but the problem is, the jigs
have so much stuff on the top, when you flip them over, all the hardware gets in the way,
preventing a 3 deg. back bevel.... any thoughts?
Seth, experiment with the angles used, angle of attack on the wood, and how often you re
sharpen...I too can get some stubborn wood that requires extra care...
Thx
Seth Ribbens
-- Seth J Ribbens
--
Seth Ribbens
Bill G
on stones, you have limited surface area unlike glass plate he uses...
b
On 5/20/2011 10:34 AM, Seth Ribbens wrote:
> Bill,
>
> Watch Brent's video. I found it much quicker to understand his process than reading it.
>
> http://www.youtube.com/watch?v=h8TNuXSuYGM
>
> -- Seth J Ribbens
>
>
> On Fri, May 20, 2011 at 11:35 AM, Brent Beach <brent...@gmail.com
> <mailto:brent...@gmail.com>> wrote:
>
> Hi Bill
>
>
> On 20/05/2011 8:58 AM, Bill G wrote:
>
> Hi Seth, thx for sharing your experiences....
> I am curious, how do you achieve the back bevel?
>
> I wish there was a single jig that enabled you to mount a plane blade,
> and simply sharpen, then flip over, and work the back bevel.... how do
> you work the back bevel, with the ruler trick?
>
>
> Funny you should ask that question on this group!
>
> Google 'brent beach sharpening jig'!
>
> Brent
> --
> Victoria, B.C., Canada
>
>
> --
> You received this message because you are subscribed to the Google Groups
> "Sharpening jig" group.
> To post to this group, send email to sharpen...@googlegroups.com
> <mailto:sharpen...@googlegroups.com>.
> To unsubscribe from this group, send email to
> sharpening-ji...@googlegroups.com
> <mailto:sharpening-jig%2Bunsu...@googlegroups.com>.
Brent Beach
The shapton stone is not the best abrasive for use on edge tools. If you
hunt around my site (the is a search specific to the site at the top of
each page) for shapton you will find a discussion and links to other
sites with images of the scratch patterns left by shapton stones.
The first problem is that each shapton stone appears to include large
grit particles for speed and small grit particles to get the grit grade.
Large particles damage the metal in the edge tool well below the
surface. If your final abrasive used at the edge includes large
particles, your edge is left in a shattered state. That means it will
wear faster in use. It will wear just as if you used an abrasive made up
of only the large grits.
This result, discovered in the 1870s by Henry Sorby is taking some time
to make it through to the tool using community. It is taking longer to
make it through to the abrasive manufacturing community.
The 3m abrasives are uniform, sharpen as quickly if you use microbevels,
leave unshattered metal at the edge. The result - a tool that works
longer between sharpenings.
The second problem that the metallography folks discovered (this bit was
much more recent than the Sorby discoveries) is that you should not
allow filing to collect in the abrasive. When polishing specimens they
make sure that the filings are flushed from the path the specimen
follows. Using any stone in which you create a slurry - of broken
abrasive bits and filings - produces an inferior surface.
You may get the desired geometry with the shapton stones. You may even
get a surface that looks ok when examined by microscope. The underlying
metal is fractured and will more perform as it should.
Not all addictions are good for you. Like most other addictions though,
you can be cured. The second step is admitting you have a problem. The
first is discovering you have a problem. You are now well into the first
step.
Brent
--
Victoria, B.C., Canada
Bill G
On 5/20/2011 1:01 PM, Brent Beach wrote:
> Hi Bill
>
> The shapton stone is not the best abrasive for use on edge tools. If you hunt around my
> site (the is a search specific to the site at the top of each page) for shapton you will
> find a discussion and links to other sites with images of the scratch patterns left by
> shapton stones.
>
> The first problem is that each shapton stone appears to include large grit particles for
> speed and small grit particles to get the grit grade. Large particles damage the metal
> in the edge tool well below the surface. If your final abrasive used at the edge
> includes large particles, your edge is left in a shattered state. That means it will
> wear faster in use. It will wear just as if you used an abrasive made up of only the
> large grits.
Brent, are you referring to Shaptons line of GLASS stones which
are designed for A2 metal? These are the ones I use, and they seem superb.... I have
never found any paper that even comes close to these stones.... as you know, Shapton makes
many types of stones... Since I use all A2 blades, it seems like a natural fit... I am
interested in your comments...
http://www.sharpeningsupplies.com/Shapton-GlassStone-30000-Grit-P224C84.aspx
> The second problem that the metallography folks discovered (this bit was much more
> recent than the Sorby discoveries) is that you should not allow filing to collect in the
> abrasive. When polishing specimens they make sure that the filings are flushed from the
> path the specimen follows. Using any stone in which you create a slurry - of broken
> abrasive bits and filings - produces an inferior surface.
fully agreed.... I keep water flow atop the stone so I have
constant slurry removal, this is a very valid point....
So what papers produce grits as fine as these Shapton stones? The only thing I have
found close is 1/4 diamond paste?
Bill G
Seth Ribbens
Brent Beach
Check out this site
http://www.tzknives.com/razorbevels.html
He shows images of bevels prepared by various stones, with and without
slurry.
I think they only have one stone at what they call 30,000.
Brent
--
Victoria, B.C., Canada
Bill G
> http://www.tzknives.com/razorbevels.html
>
> He shows images of bevels prepared by various stones, with and without slurry.
>
> I think they only have one stone at what they call 30,000.
Interesting link.... it always made sense to remove the slurry
while sharpening..... these photos confirm such....
Seth, thx for the added links.... I considered using a similar method, but I would have to
surrender my roller type jigs, they are very convenient, they also have a roller with a
camber on it, which easily assist for an even camber on the blade....
I am intrigued by that Spyderco ultra fine stone.... I find it hard to imagine it
producing a sharper edge than the 30k shapton, but it sure looked that way from the
pix...has anyone used this stone? I can't seem to find a grit rating on it? Also, the
directions make me nervous, use a scouring pad between uses to remove slurry? How is the
stone flattened? I flatten my stone after each blade.... PITA, but without a flat stone,
you will never get a consistent straight edge. The Shapton system has its own set of
flatteners to use with their stones, this helped a lot in my sharpness...
Bill
Bill G
On 5/20/2011 2:59 PM, Brent Beach wrote:
> Bill
>
> Check out this site
>
> http://www.tzknives.com/razorbevels.html
>
> He shows images of bevels prepared by various stones, with and without slurry.
>
> I think they only have one stone at what they call 30,000.
I re looked these images.... and all I can say is, this is a tough
pill to swallow.... from what is shown the Norton 8k should match or beat a Shapton 30k...
I have all these stones and my results are quite the opposite... the 8k Norton I would
consider a bear min. for plane irons and chisels for most ww. But if you need a really
SHARP edge for nasty woods, jumping up to the Shapton 12k or 15k, and then onto the 30k
makes a huge difference in sharpness.... Once I got my set of shaptons glass ceramics, I
found no use for the Notrtons... much inferior for A2 metal.... Shapton made the glass
ceramic line specifically for A2.... some of the other previous pro stones did good on A2,
specially the 15k PRO shapton....but other than this particular grit the glass line really
excels IMO on A2....
Bill
Brent Beach
First, you could not get the blades sharp with other abrasives but can
with the shaptons.
Second, we see that the shaptons contain larger grits which accounts for
their faster cutting action.
Implication? Your sharpening technique needs more abrasive during the
final honing.
First problem - fine abrasives remove metal slowly. Second problem - we
want to use very fine abrasives with no large grits on the edge.
Solution - microbevels.
Correct use of microbevels requires that for each finer abrasive you
increase the angle so that the honing action begins with the edge
itself, not the bevel back of the edge, resting on the abrasive. Honing
then has a very narrow portion of the tool in contact with the abrasive
so that even with the finest abrasives enough metal is removed. You must
use a jig system that allows you precise increases in honing angle.
BTW, the 3M abrasives are not necessarily the fastest abrasives for a
given grit size. Abrasion rate depends on the shape of the grit
particles as well as other factors. It turns out that diamond has a
better form factor. As well, since diamond breaks down more slowly, it
retains that form factor longer. Silicon carbide is brittle so breaks
down a little faster. Each break increases the included angle on the
corner which reduces the abrasion rate. The 3M PSA sheets are a good
combination of uniform size, speed, durability and hence cost.
Brent
--
Victoria, B.C., Canada
Bill G
>
> First, you could not get the blades sharp with other abrasives but can with the shaptons.
was this a question? if so, the answer is.... I can get sharper
blades with the higher grit shapton glass stones, yes.... but most ww tasks, a norton 8k
stone is somewhat suitable, but FAR from what is I "now" consider sharp, as you know, this
is all a question of degree...I never knew what sharp was before I got the shaptons glass
up to 30k.
I tried all the 3m abrasives on glass, sharpness no where near what the Shapton glass
ceramics produced for A2 metal.... although, from a cost-effective standpoint, the 3m can
not be beat...
>
> Second, we see that the shaptons contain larger grits which accounts for their faster
> cutting action.
that is the part I am curious about from those pix, I am not convinced
my 30k shapton stone has grit sizes equal to the Norton 8k... makes no sense to me....I
need a good microscope...can you suggest one?
>
> Implication? Your sharpening technique needs more abrasive during the final honing.
with stones, there is endless of supply of abrasive, specially
considering I flatten after every blade contact....
>
> First problem - fine abrasives remove metal slowly. Second problem - we want to use very
> fine abrasives with no large grits on the edge.
>
> Solution - microbevels.
>
> Correct use of microbevels requires that for each finer abrasive you increase the angle
> so that the honing action begins with the edge itself, not the bevel back of the edge,
> resting on the abrasive. Honing then has a very narrow portion of the tool in contact
> with the abrasive so that even with the finest abrasives enough metal is removed. You
> must use a jig system that allows you precise increases in honing angle.
Ok, this is a very valid point, and another great
contribution, thx for that.... just the slightest angle change will assure you are just
making contact with the edge vs. the entire bevel, whereas you might be working the other
side of the bevel more than the edge... OK... I need to re consider this point and think
of how to incorporate it...thx again.
Not trying to be argumentative about the abrasive, just sharing my experience...also, the
link of the 30k stone, did not make it clear if slurry was removed on those paticular
pictures...I find this mandatory, as the slurry metal particles can increase the effective
grit size - so you defeat the purpose of the higher grit stone....
I will also mention, while the 30k stones gets me to a new level of sharpness, an edge
this fine has a very short life span, but at the same time, it cuts knarly wood like
nothing else I have ever experienced....
Bill
Brent Beach
On 22/05/2011 8:27 AM, Bill G wrote:
> HI Brent
>>
>> First, you could not get the blades sharp with other abrasives but can
>> with the shaptons.
>
> was this a question? if so, the answer is.... I can get sharper blades
> with the higher grit shapton glass stones, yes.... but most ww tasks, a
> norton 8k stone is somewhat suitable, but FAR from what is I "now"
> consider sharp, as you know, this is all a question of degree...I never
> knew what sharp was before I got the shaptons glass up to 30k.
How do you measure sharp?
No matter what shapton says about the grit in their 30k stone, it is a
fact that finer grits remove metal more slowly. If the 30k is removing
metal faster is it a larger grit.
If you cannot get a blade sharp with 8K then you are not achieving the
geometry you are trying for.
If you are not removing enough metal with the other abrasives you have a
technique problem, not an abrasive problem.
>
> I tried all the 3m abrasives on glass, sharpness no where near what the
> Shapton glass ceramics produced for A2 metal.... although, from a
> cost-effective standpoint, the 3m can not be beat...
The 3m microfinishing abrasives can achieve a flat bevel at any desired
angle provided they are used correctly. Failure to get the angle is a
failure of technique, not a failure of the abrasive.
>> Second, we see that the shaptons contain larger grits which accounts
>> for their faster cutting action.
> that is the part I am curious about from those pix, I am not convinced
> my 30k shapton stone has grit sizes equal to the Norton 8k... makes no
> sense to me....I need a good microscope...can you suggest one?
The QX5, if you can find one, will let you see the scratches you are
making. A more expensive microscope will produce better results. There
are a lot of microscopes out there these days with USB connections - I
have only used the QX3 and a standard inspection microscope that I could
never attach a camera to in a way that let me get consistent good pictures.
Microscopy is not easy. Lots of web resources though if you look around.
>>
>> Implication? Your sharpening technique needs more abrasive during the
>> final honing.
>
> with stones, there is endless of supply of abrasive, specially
> considering I flatten after every blade contact....
The ability of a piece of grit to remove metal depends, in part, on the
shape of the grit. Abrasive grits have a natural shape and an unnatural
shape. The unnatural shape is their shape after having a corner broken off.
You break a corner off by using the abrasive and in some cases by
flattening the abrasive. For very hard stones - stones with a very hard
bonding agent - flattening may mean shattering the abrasives rather than
pulling abrasives from the bonding matrix. Flattening such a stone with,
for example, a diamond stone, makes the stone much less effective.
Of course, using a jig that rolls on the abrasive does nothing to
improve the shape of the grits either.
>> First problem - fine abrasives remove metal slowly. Second problem -
>> we want to use very fine abrasives with no large grits on the edge.
>>
>> Solution - microbevels.
>>
>> Correct use of microbevels requires that for each finer abrasive you
>> increase the angle so that the honing action begins with the edge
>> itself, not the bevel back of the edge, resting on the abrasive.
>> Honing then has a very narrow portion of the tool in contact with the
>> abrasive so that even with the finest abrasives enough metal is
>> removed. You must use a jig system that allows you precise increases
>> in honing angle.
>
>
> Ok, this is a very valid point, and another great contribution, thx for
> that.... just the slightest angle change will assure you are just making
> contact with the edge vs. the entire bevel, whereas you might be working
> the other side of the bevel more than the edge... OK... I need to re
> consider this point and think of how to incorporate it...thx again.
>
>
> Not trying to be argumentative about the abrasive, just sharing my
> experience...also, the link of the 30k stone, did not make it clear if
> slurry was removed on those paticular pictures...I find this mandatory,
> as the slurry metal particles can increase the effective grit size - so
> you defeat the purpose of the higher grit stone....
Generally the filings tumble between the abrasive and the bevel.
Tumbling pieces can dent the bevel, but don't remove metal. Bevels
worked in a slurry have a very different look under magnification than
bevels worked without a slurry. Rather than scratches across the bevel,
you get a matte finish - zillions of small dents that scatter the light.
Fractured metal below the surface, no metal removal, weakened metal, not
a durable tool.
> I will also mention, while the 30k stones gets me to a new level of
> sharpness, an edge this fine has a very short life span, but at the same
> time, it cuts knarly wood like nothing else I have ever experienced....
The sharpness of the edge is a function of the included angle, not the
abrasive used to achieve it.
The durability of the edge, for a given final included angle, is a
function of the final abrasive (assuming you have worked through the
fractured layer). Finer abrasives produce more durable edges, assuming
that enough of the fractured layer has been removed.
You are defining sharpness by the ability to cut gnarly wood. We are
talking plane irons or chisels here, right?
If you are using the same included angle and getting different ability
to cut wood then something else is happening.
What is gnarly wood? What species? What problems does the wood have?
The description of your tools - cuts gnarly wood, has a short life span
- is a real puzzle to me. It suggests some kind of serrated edge or an
edge with a burr or something. I have never had an edge that I would
describe as you have described your edge. If I did, I am not sure I
would call it sharp though.
Brent
--
Victoria, B.C., Canada
Bill G
> How do you measure sharp?
by how it cuts difficult wood... its subjective, but its obvious....
>
> No matter what shapton says about the grit in their 30k stone, it is a fact that finer
> grits remove metal more slowly. If the 30k is removing metal faster is it a larger grit.
I never mentioned it removes meatal faster?
>
>
> If you cannot get a blade sharp with 8K then you are not achieving the geometry you are
> trying for.
I can get blade sharp with 8k, just not as sharp as 15k or 30k...
makes sense to me?
>
> If you are not removing enough metal with the other abrasives you have a technique
> problem, not an abrasive problem.
why a technique problem? The finer the abrasive, the
sharper the blade, doesn't that stand to reason?
> The 3m microfinishing abrasives can achieve a flat bevel at any desired angle provided
> they are used correctly. Failure to get the angle is a failure of technique, not a
> failure of the abrasive.
I can get a bevel with a 1000 grit stone, that doesn't
mean it will be as sharp as 30k stone...it seems you are suggesting, grit size is
irrelevant to sharpness?
> The sharpness of the edge is a function of the included angle, not the abrasive used to
> achieve it.
are you suggesting a 1k stone can achieve same sharpness as a 30k
stone, using the same technique???
> You are defining sharpness by the ability to cut gnarly wood. We are talking plane irons
> or chisels here, right?
Yes...
>
> If you are using the same included angle and getting different ability to cut wood then
> something else is happening.
>
> What is gnarly wood? What species? What problems does the wood have?
Burls, hard end-grain, etc. or even just regular hard
woods, my blades sharpened up to 30k stone, cut easier, i.e. less force required vs. when
I stop at 8k stone.
>
> The description of your tools - cuts gnarly wood, has a short life span - is a real
> puzzle to me. It suggests some kind of serrated edge or an edge with a burr or
> something. I have never had an edge that I would describe as you have described your
> edge. If I did, I am not sure I would call it sharp though.
The sharper the edge, the finer the tip...the easier it
gets nicked.... so when I start with a 30k sharpned blade... for an example, after 20
strokes with a planer, it will act as if was sharpened to 15k stone....then another 15-20
strokes, it will perform like a blade sharpened to 8k... then it levels off for some time,
eventually, of course, this will need sharpening again, as it will cut equal to a 2k
sharpened blade... that is the progression of an edge, it dulls with use....what am I
missing here?
Bill