I own the LV low angle smoother and have an extra blade, the high angle
optional blade, ground at the factory to 35 degrees. I've known for
some time that putting a back bevel on it is supposed to reduce tear out
but being the procrastinator that I am, I hadn't ground the back bevel
until this afternoon. I put an 8 degree (give or take) bevel, 1 mm wide
on the back and gave it a work out on an oak drawer front that I'd set
aside early this year because I couldn't tame the tear out without
sanding it forever.

Early this year: A couple runs through the planer resulted in tear out
no matter how light a cut or which direction. By the time I'd run it
through a few times, I decided it was too thin to be installed along
side the other drawers and ended up cutting a new front. If I'd owned a
thickness sander, I would have put it through that in the first place,
but being in a hurry to remove old stain, I ran a bunch of drawer fronts
through the planer after scraping off the lacquer finish. The rest came
out flawless.

I found that problematic drawer front today and gave it a go with the
modified plane blade. It was like a miracle! Almost like using a
scraper plane, but faster. The surface was left silky and all the
divots disappeared after a half dozen strokes. Very cool.

Oh, and kudos for Robin and company designing the new honing guide. It
paid for itself today.


And I know nearly every one of you here already knows about back
beveling a blade. I just wanted to share...

Question: Wouldn't a back bevel on planer blades make them chip and wear
out much faster?

Is there a 12 step program for procrastinators?



Dave

David wrote:
I own the LV low angle smoother and have an extra blade, the high angle
optional blade, ground at the factory to 35 degrees. I've known for
some time that putting a back bevel on it is supposed to reduce tear out
but being the procrastinator that I am, I hadn't ground the back bevel
until this afternoon. I put an 8 degree (give or take) bevel, 1 mm wide
on the back and gave it a work out on an oak drawer front that I'd set
aside early this year because I couldn't tame the tear out without
sanding it forever.

Early this year: A couple runs through the planer resulted in tear out
no matter how light a cut or which direction. By the time I'd run it
through a few times, I decided it was too thin to be installed along
side the other drawers and ended up cutting a new front. If I'd owned a
thickness sander, I would have put it through that in the first place,
but being in a hurry to remove old stain, I ran a bunch of drawer fronts
through the planer after scraping off the lacquer finish. The rest came
out flawless.

I found that problematic drawer front today and gave it a go with the
modified plane blade. It was like a miracle! Almost like using a
scraper plane, but faster. The surface was left silky and all the
divots disappeared after a half dozen strokes. Very cool.

Oh, and kudos for Robin and company designing the new honing guide. It
paid for itself today.


And I know nearly every one of you here already knows about back
beveling a blade. I just wanted to share...

Question: Wouldn't a back bevel on planer blades make them chip and wear
out much faster?

Is there a 12 step program for procrastinators?



Dave
Nope, just two step. One step forward, two steps
back. That's the procrastinator. Just reverse
that for the solution.

"David" wrote in message
. ..
I own the LV low angle smoother and have an extra blade, the high angle
optional blade, ground at the factory to 35 degrees. I've known for
some time that putting a back bevel on it is supposed to reduce tear out
but being the procrastinator that I am, I hadn't ground the back bevel
until this afternoon. I put an 8 degree (give or take) bevel, 1 mm wide
on the back and gave it a work out on an oak drawer front that I'd set
aside early this year because I couldn't tame the tear out without
sanding it forever.

I cannot argue with your good results. What I don't understand is why this
worked as well as it did. As I understand it, you added a bevel on the
opposite side of the normal bevel. This is the definition of a back bevel
for standard bevel-down configuration. It increases the cutting angle.
However, on a bevel-up plane such as the LV low angle smoother, it has no
affect on the cutting angle. To increase the angle, you would shift the
angle from the factory ground 35 degree angle to something like 40 degrees
or add a 5 degree microbevel.

Did I misunderstand something?

Bob

"BillyBob" wrote in message
k.net...

Did I misunderstand something?

Chip form.

"George" George@least wrote in message
...

"BillyBob" wrote in message
k.net...

Did I misunderstand something?

Chip form.

I don't have any idea what your two word reply means. Would you like to
expand that answer?

Bob

BillyBob wrote:

"David" wrote in message
. ..

I own the LV low angle smoother and have an extra blade, the high angle
optional blade, ground at the factory to 35 degrees. I've known for
some time that putting a back bevel on it is supposed to reduce tear out
but being the procrastinator that I am, I hadn't ground the back bevel
until this afternoon. I put an 8 degree (give or take) bevel, 1 mm wide
on the back and gave it a work out on an oak drawer front that I'd set
aside early this year because I couldn't tame the tear out without
sanding it forever.


I cannot argue with your good results. What I don't understand is why this
worked as well as it did. As I understand it, you added a bevel on the
opposite side of the normal bevel. This is the definition of a back bevel
for standard bevel-down configuration. It increases the cutting angle.
However, on a bevel-up plane such as the LV low angle smoother, it has no
affect on the cutting angle. To increase the angle, you would shift the
angle from the factory ground 35 degree angle to something like 40 degrees
or add a 5 degree microbevel.

Did I misunderstand something?

Bob


I can't find anything to cite that says a back bevel would reduce tear
out in a bevel up plane, but it works on the tear out prone oak I have.
Normally, a back bevel is used to increase the effective cutting angle
on a bevel down plane. It might be serendipity at work. I'll leave the
bevel on that blade unless I have issues with planing other boards.

Dave

David wrote:
:
: I cannot argue with your good results. What I don't understand is why this
: worked as well as it did. As I understand it, you added a bevel on the
: opposite side of the normal bevel. This is the definition of a back bevel
: for standard bevel-down configuration. It increases the cutting angle.
: However, on a bevel-up plane such as the LV low angle smoother, it has no
: affect on the cutting angle. To increase the angle, you would shift the
: angle from the factory ground 35 degree angle to something like 40 degrees
: or add a 5 degree microbevel.
:
: Did I misunderstand something?
:
: Bob
:
:
: I can't find anything to cite that says a back bevel would reduce tear
: out in a bevel up plane, but it works on the tear out prone oak I have.
: Normally, a back bevel is used to increase the effective cutting angle
: on a bevel down plane. It might be serendipity at work. I'll leave the
: bevel on that blade unless I have issues with planing other boards.

I'm confused as well. If you're putting a secondary bevel opposite the
main one, won't this prevent the edge from contacting the wood entirely?







-- Andy Barss

"Andrew Barss" wrote in message
...
David wrote:
:
: I cannot argue with your good results. What I don't understand is why
this
: worked as well as it did. As I understand it, you added a bevel on the
: opposite side of the normal bevel. This is the definition of a back
bevel
: for standard bevel-down configuration. It increases the cutting angle.
: However, on a bevel-up plane such as the LV low angle smoother, it has
no
: affect on the cutting angle. To increase the angle, you would shift the
: angle from the factory ground 35 degree angle to something like 40
degrees
: or add a 5 degree microbevel.
:
: Did I misunderstand something?
:
: Bob
:
:
: I can't find anything to cite that says a back bevel would reduce tear
: out in a bevel up plane, but it works on the tear out prone oak I have.
: Normally, a back bevel is used to increase the effective cutting angle
: on a bevel down plane. It might be serendipity at work. I'll leave the
: bevel on that blade unless I have issues with planing other boards.

I'm confused as well. If you're putting a secondary bevel opposite the
main one, won't this prevent the edge from contacting the wood entirely?







-- Andy Barss

I tried it and it works. Robin Lee and Rob Cosman both recommend it. As I
understand it, the slight back bevel makes the cutting edge absolutely
straight and incredibly sharp

--
Lowell Holmes

"BillyBob" wrote in message
nk.net...

"George" George@least wrote in message
...

"BillyBob" wrote in message
k.net...

Did I misunderstand something?

Chip form.

I don't have any idea what your two word reply means. Would you like to
expand that answer?


The back bevel also causes the shaving to curl faster, breaking it over a
relatively shorter radius, depriving it of long fiber strength to tear out.
http://www.leevalley.com/images/item...s/05p2301e.jpg

Shows the exaggerated view.

"George" George@least wrote in message
...

The back bevel also causes the shaving to curl faster, breaking it over a
relatively shorter radius, depriving it of long fiber strength to tear
out.
http://www.leevalley.com/images/item...s/05p2301e.jpg

Shows the exaggerated view.


Thanks for posting the link. This picture illustates exactly the point I've
been trying to make. That's a picture of a bevel down (conventional) plane.
The Lee Valley Low angle smoother described by the OP is a bevel up plane,
like a block plane. Back bevel does not affect cutting angle on a bevel up
plane, so I don't understand why he got better results unless his plane just
wasn't sharp to begin with.

Bob

"Lowell Holmes" wrote in message
news:VLX%e.4156$097.2187@trnddc01...

I tried it and it works. Robin Lee and Rob Cosman both recommend it. As I
understand it, the slight back bevel makes the cutting edge absolutely
straight and incredibly sharp

You tried it on a bevel up plane?

Bob

"BillyBob" wrote in message
news

"George" George@least wrote in message
...

The back bevel also causes the shaving to curl faster, breaking it over a
relatively shorter radius, depriving it of long fiber strength to tear
out.
http://www.leevalley.com/images/item...s/05p2301e.jpg

Shows the exaggerated view.


Thanks for posting the link. This picture illustates exactly the point
I've
been trying to make. That's a picture of a bevel down (conventional)
plane.
The Lee Valley Low angle smoother described by the OP is a bevel up plane,
like a block plane. Back bevel does not affect cutting angle on a bevel up
plane, so I don't understand why he got better results unless his plane
just
wasn't sharp to begin with.


It affects clearance angle, which can increase the sharpness angle while
making the edge more durable. See Hoadly on sharpness.

George wrote:

"BillyBob" wrote in message
news
"George" George@least wrote in message
...


The back bevel also causes the shaving to curl faster, breaking it over a
relatively shorter radius, depriving it of long fiber strength to tear

out.

http://www.leevalley.com/images/item...s/05p2301e.jpg

Shows the exaggerated view.


Thanks for posting the link. This picture illustates exactly the point
I've
been trying to make. That's a picture of a bevel down (conventional)
plane.
The Lee Valley Low angle smoother described by the OP is a bevel up plane,
like a block plane. Back bevel does not affect cutting angle on a bevel up
plane, so I don't understand why he got better results unless his plane
just
wasn't sharp to begin with.



It affects clearance angle, which can increase the sharpness angle while
making the edge more durable. See Hoadly on sharpness.


Maybe that's part of the explanation for why it helped. For grins I
ground off the bevel and put a TINY back bevel that was maybe 1/4 to 1/3
of a MM. It wouldn't even cut. I had the blade sticking way out from
the sole of the plane and got no cutting action. I guess I got lucky
the first time I put a back bevel on (1 MM wide). The blade was sharp
before I did that, and I'm not really sure if I had tried it early this
year on that tear out prone drawer front. Maybe it would have worked ok
with no back bevel, but I must say it worked very well with a 1 MM
bevel, but was useless with a tiny BB. I do realize that BB are
primarily for bevel down planes.

Dave

"George" George@least wrote in message
...
It affects clearance angle, which can increase the sharpness angle while
making the edge more durable. See Hoadly on sharpness.

What is clearance angle? Who or what is Hoadly?

Bob

"George" George@least wrote in message
...

It affects clearance angle, which can increase the sharpness angle while
making the edge more durable. See Hoadly on sharpness.

How does it make the edge more durable? It seems to me that it makes the
cutting edge thinner, which results in an edge that will dull quicker.
Since its a bevel up plane, the angle of cut remains the same and the back
bevel just removes more metal behind the cutting edge.

Bob

"David" wrote in message
...

Maybe that's part of the explanation for why it helped.

I'm pretty convinced that you simply produced a better sharpening job,
rather than making any shift in the planing geometry. That's why it worked.

I was a little surprised you mentioned you had trouble with tear out on the
oak to begin with. I've not had much trouble with oak and the smoothers I
own. I did not do anything special to them except sharpen them. Now when
they were not so sharp, I had all kinds of trouble with tear out.

Bob

"BillyBob" writes:

"George" George@least wrote in message
...

It affects clearance angle, which can increase the sharpness angle while
making the edge more durable. See Hoadly on sharpness.

How does it make the edge more durable? It seems to me that it makes the
cutting edge thinner, which results in an edge that will dull quicker.

Au contraire.

Since its a bevel up plane, the angle of cut remains the same and the back
bevel just removes more metal behind the cutting edge.

No:
/
/
/
/
| Exaggerated back bevel on bevel up plane
| /
| /
| /
|________/



/
/
/
/
| No back bevel on bevel up plane
| /
| /
| /
|/

--
Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
Phone: +49 228 73 2447 FAX ... 7869
Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23

On Tue, 04 Oct 2005 17:02:06 GMT, "BillyBob"
wrote:


"George" George@least wrote in message
...

It affects clearance angle, which can increase the sharpness angle while
making the edge more durable. See Hoadly on sharpness.

How does it make the edge more durable? It seems to me that it makes the
cutting edge thinner, which results in an edge that will dull quicker.
Since its a bevel up plane, the angle of cut remains the same and the back
bevel just removes more metal behind the cutting edge.

Bob



back beveling a bevel up plane makes the edge thicker.

that is if you define the back as the side of the blade without a
bevel. if you define the back as the side away from the wood, then a
*front* bevel would make the edge thicker.

regardless of that bit of obfuscation, any secondary bevel, front back
or inside out will make the edge thicker. that's all fine and good
until the angle of the bevel against the wood exceeds the angle of
attack- or as someone else moer clearly just called it, the clearance
angle. when that happens the plane ceases to cut.

BillyBob wrote:

"David" wrote in message
...


Maybe that's part of the explanation for why it helped.


I'm pretty convinced that you simply produced a better sharpening job,
rather than making any shift in the planing geometry. That's why it worked.

I was a little surprised you mentioned you had trouble with tear out on the
oak to begin with. I've not had much trouble with oak and the smoothers I
own. I did not do anything special to them except sharpen them. Now when
they were not so sharp, I had all kinds of trouble with tear out.

Bob


I agree that may be what happened. I've don't often get a piece of red
oak that tears out a lot, but this ONE piece has got a couple square
inches area that's a bear to plane cleanly. I got it perfectly smooth,
then grabbed low angle block plane and in one pass left it looking
ragged again. That area, when smooth, looks to my eye like the rest of
the surface. Is there no way to tell what wood will tear out, by some
visible feature, in the grain?

Dave

s wrote:

On Tue, 04 Oct 2005 17:02:06 GMT, "BillyBob"
wrote:


"George" George@least wrote in message
...


It affects clearance angle, which can increase the sharpness angle while
making the edge more durable. See Hoadly on sharpness.

How does it make the edge more durable? It seems to me that it makes the
cutting edge thinner, which results in an edge that will dull quicker.
Since its a bevel up plane, the angle of cut remains the same and the back
bevel just removes more metal behind the cutting edge.

Bob




back beveling a bevel up plane makes the edge thicker.

that is if you define the back as the side of the blade without a
bevel. if you define the back as the side away from the wood, then a
*front* bevel would make the edge thicker.

regardless of that bit of obfuscation, any secondary bevel, front back
or inside out will make the edge thicker. that's all fine and good
until the angle of the bevel against the wood exceeds the angle of
attack- or as someone else moer clearly just called it, the clearance
angle. when that happens the plane ceases to cut.
I never thought of it that way. I drew a couple pictures real quick, as
I read your statement. I agree. seems counter-intuitive, doesn't it??

Dave

"David" wrote in message
. ..

ragged again. That area, when smooth, looks to my eye like the rest of
the surface. Is there no way to tell what wood will tear out, by some
visible feature, in the grain?

I don't have a weatlh of experience, but I know when the grain looks like
little eddys in a pool of water its going to be a bear. With a very sharp
blade, you are able to make other adjustments that help tear out. First,
set the cut depth to make very thin shavings. If the plane has a mouth
adjustment, set it very tight. Lastly, planing diagonally or in kind of a
swirling motion may help with these tough areas. Alternatively, a cabinet
scraper may save the day.

Bob

"Juergen Hannappel" wrote in message
...
How does it make the edge more durable? It seems to me that it makes
the
cutting edge thinner, which results in an edge that will dull quicker.

Au contraire.

Since its a bevel up plane, the angle of cut remains the same and the
back
bevel just removes more metal behind the cutting edge.

No:

I am always willing to admit I am wrong. You are right, I was wrong. Thank
you for posting the pictures, that helps. I've learned something Back
bevel does indeed make the edge more durable. I had it confused with micro
bevel.

Bob

wrote in message
...

back beveling a bevel up plane makes the edge thicker.

You are correct. I confused back bevel with micro bevel. I need to take my
own advise often given out. When in doubt draw pictures or make a model to
really understand.

Thanks,
Bob

"Australopithecus scobis" wrote in message
news
bevel angle consistent with edge retention. The effect of a back bevel on
a bevel-up blade might affect the edge's strength, so the OP planed for
longer periods with a truly sharp blade.

Ah, thanks for that insight. I'm going to go do a back bevel on one of my
planes. I need to exercise my new Lee Valley honing jig. :-)

Bob

BillyBob wrote:

"David" wrote in message
. ..


ragged again. That area, when smooth, looks to my eye like the rest of
the surface. Is there no way to tell what wood will tear out, by some
visible feature, in the grain?


I don't have a weatlh of experience, but I know when the grain looks like
little eddys in a pool of water its going to be a bear. With a very sharp
blade, you are able to make other adjustments that help tear out. First,
set the cut depth to make very thin shavings. If the plane has a mouth
adjustment, set it very tight. Lastly, planing diagonally or in kind of a
swirling motion may help with these tough areas. Alternatively, a cabinet
scraper may save the day.

Bob


I do set the plane for very light cuts and the mouth so narrow you have
to hold it just right to see daylight through the tiny slit. I have
a LV scraper plane which I've learned to adjust pretty well now, so that
I can get a wonderfully smooth surface. Thanks for the additional
suggestion (swirling), Bob.

Dave

......about why back bevels work (on bevel down planes)....


Chip form.

I don't have any idea what your two word reply means. Would you like to
expand that answer?

Bob



tearout happens in stringy woods when the wood fiber is strong enough
to pull up ahead of the cutting edge. think of sliding a putty knife
under the lifted end if a splinter. it levers the splinter out of the
board, ahead of the edge of the knife. now imagine lifting the handle
of the putty knife up until the splinter breaks. you've increased the
angle beyond the bending ability of the splinter.

this is what the back bevel does. it forces the shaving to curl to the
point that the long fibers can no longer apply upward action ahead of
the edge. it also increases the total included grind angle (makes the
edge thicker) which tends to make it stay sharp a bit longer between
sharpenings.

On Wed, 05 Oct 2005 23:14:48 -0500, Australopithecus scobis
wrote:

On Wed, 05 Oct 2005 11:30:18 -0700, bridgerfafc wrote:

this is what the back bevel does. it forces the shaving to curl to the
point that the long fibers can no longer apply upward action ahead of
the edge.

That doesn't make sense to me--unless: The back bevel (we're still on
bevel-up planes, right?)

the quoted was about bevel down planes. sorry about the confusion...



is going to change the relief angle. Are the long
fibers you're talking about the ones under the blade, after the edge has
passed? If so, it makes sense; back bevel in the bevel-up situation will
lower the relief angle. The back-bevel could put a teensy bit of pressure
on the fibers just below the fibers which are now riding up the blade.
These still-in-the-wood fibers can't join the growing 'splinter' ahead of
the blade, because we're pinching them back against the wood. I think...

nah if the heel of that bevel is deeper than the edge the plane will
climb right out of the cut.





Whatever, I still think OP just had a sharper blade.

probably.

In article ,
Australopithecus scobis wrote:

That doesn't make sense to me--unless: The back bevel (we're still on
bevel-up planes, right?) is going to change the relief angle. Are the long
fibers you're talking about the ones under the blade, after the edge has
passed? If so, it makes sense; back bevel in the bevel-up situation will
lower the relief angle. The back-bevel could put a teensy bit of pressure
on the fibers just below the fibers which are now riding up the blade.
These still-in-the-wood fibers can't join the growing 'splinter' ahead of
the blade, because we're pinching them back against the wood. I think...

Pictures & text here (scroll down):

http://www.leevalley.com/shopping/Instructions.aspx?p=51880

djb

--
Life. Nature's way of keeping meat fresh. -- Dr. Who

wrote in message
...
nah if the heel of that bevel is deeper than the edge the plane will
climb right out of the cut.

Two thoughts.

First, can you really tell which is the bevel and which the flat surface
when you're talking the engaged (1/8") end of the blade? Answer is no, of
course. It's a rake angle, sharpness angle, clearance angle clockwise sum
to 90 degrees. Makes no difference which side the bevel is on when
considering the sharpness angle..

Second, have you looked at Hoadley, specifically chapter eight? Pretty
good stuff.

Dave Balderstone wrote:

Pictures & text here (scroll down):

http://www.leevalley.com/shopping/Instructions.aspx?p=51880

djb

That link has an excellent explanation of back bevels for both bevel up
and down blades.

Dave