JT

John Thomas

20/10/2004 7:28 PM

What's wrong with this idea?[sharpening]

Folks,

Don't think I've heard of anyone doing this, so I'm guessing there's a
reason!

I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
how would the disk work as a way to establish a primary bevel on either
chisels or plane irons?

I know rpm is going to be a factor -- I've looked at several combo
units; the rpm of the disk has either been 1720 or 3450; I would think
with care, I could avoid too much heat, especially with a 1720 rpm unit.

So, what else am I missing? Any thoughts, horror stories, or words of
encouragement?

Regards,

JT


This topic has 12 replies

Sd

Silvan

in reply to John Thomas on 20/10/2004 7:28 PM

20/10/2004 7:03 PM

John Thomas wrote:

> Don't think I've heard of anyone doing this, so I'm guessing there's a
> reason!
>
> I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
> how would the disk work as a way to establish a primary bevel on either
> chisels or plane irons?

I've been doing this for a long time. A belt sander is a fast way to really
screw up an edge, so that's why I use a suitable angle guide.

I have a 4"x36" combo with 6" discs. I drilled/tapped holes onto the side
of the platten for mounting an auxiliary table. I mount a plane blade or
chisel in a Lee Valley angle jig flummy, then I put the initial bevel on it
on a 100 grit belt. I find I rarely have heat problems, and can just about
leave the blade in contact with the belt continuously. On smaller edges
that heat up faster, a rocking sand-rest-sand-rest motion is sustainable
pretty much forever without overheating. I don't think I've burnt an edge
yet.

The auxiliary table isn't exactly in the same plane as the belt, and the
thickness of the belt, and the little hump where the seam is all conspire
to produce an angle that's a little off compared to the target. However,
it does the muscle work, and I can run through the rest of the grits (from
100 again up through 2,000) pretty quickly to put on a perfect mirror edge
that can cut the hair off a gnat's ass. The beauty of my system is that
the tool stays in the same angle guide throughout both phases of the
operation. It does introduce small errors, as I've said, but I feel like
these are easier to cope with than having two completely different angle
setups, and trying to keep both of them in sync.

I've been sharpening things this way for a pretty good while now, and it
works fine for me. With the sander you're talking about, it might work
even better. Larger belt, more surface area to dissipate heat. I would
guess. Motor speed and roller size could both add up to your sander
tearing up ground a lost faster than mine. YMMV. Caveat emptor.
Batteries not included. Not all parts included with all sets. Color and
finish may vary from those depicted here. Some assembly required. DANGER:
SHARP EDGES. The lacquer finish is not covered under warranty.

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/
http://rosegarden.sourceforge.net/tutorial/

Lr

"Leon"

in reply to John Thomas on 20/10/2004 7:28 PM

20/10/2004 7:45 PM


"John Thomas" <[email protected]> wrote in message
news:[email protected]...
> Folks,
>
> Don't think I've heard of anyone doing this, so I'm guessing there's a
> reason!
>
> I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
> how would the disk work as a way to establish a primary bevel on either
> chisels or plane irons?

IIRC a pretty common prractice. The closer to the center of the disk, the
less heat from cutting speed.



sS

[email protected] (Scott Lurndal)

in reply to John Thomas on 20/10/2004 7:28 PM

20/10/2004 10:09 PM

John Thomas <[email protected]> writes:
>Folks,
>
>Don't think I've heard of anyone doing this, so I'm guessing there's a
>reason!
>
>I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
>how would the disk work as a way to establish a primary bevel on either
>chisels or plane irons?

I use my 6x48 belt sander exclusively for primary bevel on
plane blades. Built a jig that mounts on the sander to
hold the blade at a 30 degree angle to the platen.

scott

PB

Pat Barber

in reply to John Thomas on 20/10/2004 7:28 PM

20/10/2004 8:49 PM

You have heard of "Scary Sharp" ??? Well, with your
method, it's "Really scary to Sharpen" but I must
admit that my hoe(ho) and my axe(ax) get a little of
the old 6x48 from time to time.

Just be careful... You don't want to be flinging(throw)
any sharp tools at yourself during the operation.

Of course you will be wearing safety glasses during this.




John Thomas wrote:

> Folks,
>
> Don't think I've heard of anyone doing this, so I'm guessing there's a
> reason!
>
> I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
> how would the disk work as a way to establish a primary bevel on either
> chisels or plane irons?
>
> I know rpm is going to be a factor -- I've looked at several combo
> units; the rpm of the disk has either been 1720 or 3450; I would think
> with care, I could avoid too much heat, especially with a 1720 rpm unit.
>
> So, what else am I missing? Any thoughts, horror stories, or words of
> encouragement?
>
> Regards,
>
> JT

DW

Don Wheeler

in reply to John Thomas on 20/10/2004 7:28 PM

20/10/2004 4:27 PM

John Thomas <[email protected]> wrote in
news:[email protected]:

> Folks,
>
> Don't think I've heard of anyone doing this, so I'm guessing there's a
> reason!
>
> I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
> how would the disk work as a way to establish a primary bevel on either
> chisels or plane irons?
>
> I know rpm is going to be a factor -- I've looked at several combo
> units; the rpm of the disk has either been 1720 or 3450; I would think
> with care, I could avoid too much heat, especially with a 1720 rpm unit.
>
> So, what else am I missing? Any thoughts, horror stories, or words of
> encouragement?
>
> Regards,
>
> JT

One caution: Don't be stupid as I was and leave a dust collection bag on
the sander. My belt sander bag now has several patches. Sparks and sawdust
don't mix.

Don

JT

John Thomas

in reply to John Thomas on 20/10/2004 7:28 PM

21/10/2004 12:52 AM

Pat Barber <[email protected]> wrote in news:UbAdd.727787
[email protected]:

> Of course you will be wearing safety glasses during this.
>

But of course! I'm married to Mrs Safety. And that's a good thing.

Seriously, I've gotten some good input so far, thanks everyone!;
Regards,
JT

lL

[email protected] (Lawrence Wasserman)

in reply to John Thomas on 20/10/2004 7:28 PM

21/10/2004 1:50 PM

In article <[email protected]>,
John Thomas <[email protected]> wrote:
>Folks,
>
>Don't think I've heard of anyone doing this, so I'm guessing there's a
>reason!
>
>I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
>how would the disk work as a way to establish a primary bevel on either
>chisels or plane irons?
>
>I know rpm is going to be a factor -- I've looked at several combo
>units; the rpm of the disk has either been 1720 or 3450; I would think
>with care, I could avoid too much heat, especially with a 1720 rpm unit.
>
>So, what else am I missing? Any thoughts, horror stories, or words of
>encouragement?
>
>Regards,
>
>JT

If you use the unit for woodworking also, just be careful that sparks
from grinding metal don't ignite any sawdust. Otherwise, just use the
smae precautions against overheating the steel that you would use with
a regular grinder.


--

Larry Wasserman Baltimore, Maryland
[email protected]

EP

"Edwin Pawlowski"

in reply to John Thomas on 20/10/2004 7:28 PM

20/10/2004 8:40 PM


> "John Thomas" <[email protected]> wrote in message

>> Don't think I've heard of anyone doing this, so I'm guessing there's a
>> reason!
>>
>> I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
>> how would the disk work as a way to establish a primary bevel on either
>> chisels or plane irons?

Only reason I can think of is metal residue getting onto wood. I've used my
sander for metal with good results. I have a belt sander also and it
sharpens the lawnmower blade a couple of times a year.

b

in reply to John Thomas on 20/10/2004 7:28 PM

20/10/2004 2:09 PM

On Wed, 20 Oct 2004 19:28:27 +0000 (UTC), John Thomas
<[email protected]> wrote:

>Folks,
>
>Don't think I've heard of anyone doing this, so I'm guessing there's a
>reason!
>
>I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
>how would the disk work as a way to establish a primary bevel on either
>chisels or plane irons?

just fine.

be extra careful about heating the steel.


>
>I know rpm is going to be a factor -- I've looked at several combo
>units; the rpm of the disk has either been 1720 or 3450; I would think
>with care, I could avoid too much heat, especially with a 1720 rpm unit.

keep a water can at hand and cool it before it gets hot.



>
>So, what else am I missing?

the cost of the disks? this could end up being a pretty expensive way
to grind blades.



> Any thoughts, horror stories, or words of
>encouragement?

there will be some technique issues that are pretty much specific to
this setup. go slow at first.




>
>Regards,
>
>JT

As

Australopithecus scobis

in reply to John Thomas on 20/10/2004 7:28 PM

20/10/2004 3:39 PM

On Wed, 20 Oct 2004 19:28:27 +0000, John Thomas wrote:

> I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
> how would the disk work as a way to establish a primary bevel on either
> chisels or plane irons?

Sharpening books mention belt sanders. If you have the combo, why would
you want to use the disk? Lacking a belt sander, I use a sanding disk in
my clamped electric drill to shape carving blades. It's ugly, but it does
work. I wouldn't touch a plane iron to the contraption, though.

--
"Keep your ass behind you"

AD

Andy Dingley

in reply to John Thomas on 20/10/2004 7:28 PM

21/10/2004 2:58 AM

On Wed, 20 Oct 2004 19:28:27 +0000 (UTC), John Thomas
<[email protected]> wrote:

>I'm thinking of picking up a combo sander (likely 6x48 belt + 9" disk);
>how would the disk work as a way to establish a primary bevel on either
>chisels or plane irons?

Badly. The variation in surface speed is too great across the width
of the disk, relative to the width of a plane iron.

The belt will work though.
.
Try the knifemaking group, rec.knives. Most professional knifemakers
are working with a slack-belt linisher.

--
Smert' spamionam

SK

Steve Knight

in reply to John Thomas on 20/10/2004 7:28 PM

21/10/2004 4:42 PM



>Badly. The variation in surface speed is too great across the width
>of the disk, relative to the width of a plane iron.
>
>The belt will work though.

on that small of a disc for sure. plus the abrasive will wear pretty fast too.

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.


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