Galoots

I have a web page on sharpening radiused blades.

   http://www3.telus.net/BrentBeach/Sharpen/scrubsharp.html

I use a 1" belt sander for rough grinding most edge tools - including 
shovels and axes. It works well for this. I am hoping to switch to coarser 
sheet abrasives (40 micron 3M) or waterstones, but am using the belt sander 
in the meantime. I have seen these belt sanders for $50 CDN lately.

WARNING: In order to get the angles required for plane blades, you will 
probably have to make your own tool rest!

I once did a test of various cambers as well (it must be somewhere in the 
archive). I just marked the back of the blade using templates of different 
diameters (mostly lids of various plastic containers), then ground the 
blade to match the line. Using very coarse abrasive works well without 
overheating the iron, although it is still important to cool the tool in 
water regularly.

IIRC, I first ground the blade to the desired radius, with a 90 degree 
bevel - edge first right into the belt. I then ground a 25 degree bevel the 
usual way. The very thick edge created in the first step is less likely to 
overheat while doing the second step. Only when you are getting pretty 
close on the second step is heat a problem.

I imagine the 1" belt sander would would work to put a flat face on drill 
bits as well.

Brent

Michael Campbell wrote:

> How does one grind the camber into the iron?  It's, naturally, ground
> straight right now.  I'm not above using electrons for this, but is it
> sufficient for a scrub to mark the curve I want, then freehand it on
> the grinder, then sharpen?  Seems it would be, but wanted to get some
> more learned opinions.

I picked up a cheap woodie coffin-type plane a bit ago and am
considering making it into a scrub.

How does one grind the camber into the iron?  It's, naturally, ground
straight right now.  I'm not above using electrons for this, but is it
sufficient for a scrub to mark the curve I want, then freehand it on
the grinder, then sharpen?  Seems it would be, but wanted to get some
more learned opinions.

I have a factory made ECE scrub with a perfectly round arc to the blade. 
And, I have an old beat up scrub that may have started life as a smoother 
or something else, but the point is that the arc on that one is nowhere 
near perfect.  Actually it has a bit less of an arc than the ECE plane, 
and that can come in handy.  Basically I have a "rough scrub" and a "fine 
scrub" plane, when I don't want to hog as much wood off I use the fine 
scrub. 

Generally you are using a scrub for quick removal of wood and you will 
follow with other planes to get the final surface, so the exactness of the 
arc is not important, just so it is mostly even.  At least in my humble 
opinion.

Hunter in Richmond

Michael:

For a scrub plane I use an almost-new German style single-iron 
plane. I got it with a flat edge but later ground it for scrubbing, 
and it made an incredible advance in my work. This plane went 
from being my least favorite to one of those I value most. I don't 
have any problems with the lack of a tote, and I don't think I am 
pulling on the horn, but there is an extra support for the pushing 
hand rising from the body behind the blade and possibly this 
makes a difference. Also, I don't use it for long sessions of 
planing. The edge is holding up remarkably well, I have used it 
five or six times as long as I would normally go without feeling 
the need to sharpen; I don't know if this is due to the steel or if
it 
is inherant in scrubbing.

When grinding a radius edge on the end of a blade, you have a 
choice of two directions in which you can rotate the blade. You 
may rotate the blade around the long axis of the blade, the 
direction you would rotate a drill bit when sharpening it; or you 
may rotate the blade at right angles to this axis and at right 
angles to the ground, sort of left-to-right. Either movement will 
give a curved edge, but one or the other may be easier for you 
depending on the kinds of jigs and toolrests you use. The 
difference between these types of rotation was made clearer for 
me by reading about the three types of rotation of an airplane in 
flight, but unfortunately I forget one of the terms (pitch and yaw 
are the other two) and which term applies to which form of 
rotation. Still, I think that reading about airplane movement 
clarifies the concepts.

I didn't bother laying out the arc I wanted---  I just rotated the 
blade as I held it on the grinding wheel. The height of the arc 
matters because it translates into how thick a chip you will take 
off, but exact shape doesn't seem to matter much.

You probably have an exaggerated idea of how much camber is 
needed. I think the drawings I have seen in books are probably 
exaggerated for clarity. But I am just bringing up a #6 Stanley 
that the last owner ground as a jack with what strikes the eye 
as a pleasant camber, yet with the blade extended for as deep 
a cut as I can push the chip is still only 3/4" wide---  way too 
much camber even though it looks right.  A scrub plane should 
take a deep narrow chip, and a purpose-made scrub has a 
narrow blade for this reason, but you still want the whole edge 
cutting and it is unlikely that you will be able to get off a chip 
much thicker than 1/16". 

Have fun--- I did with mine...

Tom Conroy
Berkeley

		
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Michael, I recently made a scrub blade and had good results with the
following procedure. First I established the radius on the blade. I did
this by grinding the blade perpendicular to the grinder (i.e. don't
worry about grinding a bevel yet.) When I had a radius that I liked, I
then ground the bevel. Mind you, I had great difficulty avoiding drawing
the temper when I got close to establishing an edge. Fortunately for us
that grind our own scrub blades, it's simple to regrind the radius to
remove burnt metal. So give it a shot and proceed *slowly* when you get
close to establishing an edge. The more work you do on the grinder, the
simpler it'll be to hone into a wood-hungry scrub blade. Hope this
helps. -Andy

Michael Campbell wrote:
> I picked up a cheap woodie coffin-type plane a bit ago and am
> considering making it into a scrub.
> 

In terms of wood cutting you'll be fine; the old
blades are good and thick, and a worn-out coffin
smoother has a suitably wide mouth.

But I find the handles (or lack of) on a coffin
body inadequate for vigorous scrubbing,
leading to blisters etc.

I have an old woodie with a mondo parallel
Marples blades, with a new wedge allowing
me not to use a cap-iron. I know whereof I speak.

     BugBear

Thomas Conroy wrote:
>[...]

One other plug for making a scrub plane.

I have one of the little horned ECE scrub planes, which I really like.
But the one use the most (and which works the best) is an old, beat-up
woodie jack plane.

It came with a wide open mouth.  I put a bit of radius on the
nice, thick blade; and now it hogs off wood with the best of them.

The best part is it's hard to beat the price on these things.  (As I recall,
I got mine as part of a box lot, so it was next to nothing.  But it shouldn't
be too hard to find your dream scrub for well under $10.)

N 

Michael Campbell wrote:
> I picked up a cheap woodie coffin-type plane a bit ago and am
> considering making it into a scrub.
> 
> How does one grind the camber into the iron?  It's, naturally, ground
> straight right now.  I'm not above using electrons for this, but is it
> sufficient for a scrub to mark the curve I want, then freehand it on
> the grinder, then sharpen?  Seems it would be, but wanted to get some
> more learned opinions.

I did this to a large mouthed horned coffin smoother with a tapered
blade the beginning of the year with a tailed grinder.  Mark a curve
(think I followed a tuna fish can) on the back side. present it to the
wheel straight on, back side up, till you get the curve, then present at
an angle twisting left and right until the bevel is reasonable.

If you scrub a lot you will then wish it had a tote...  ;-)

-- 
Esther Heller
bench built Windsor chairs
www.estherheller.com

I think  I am idiosyncratic on this,  but for what it is worth:

My wooden scrub planes have arced  blade ends, but they also are rounded 
on the edges of the sole and to a lesser degree across the sole.  Think 
of the bottom of the plane being like the cross section of a banister rail.

This is functional.  By tilting the plane you can change the amount of 
bite the blade takes.  It works naturally and well. Beats fiddling with 
the plane in the middle of a scrub job.

I did not make them that way.  They came that way.  Crazy 
German-Norwegian-Swedish-Finnish in our area.

A couple have a rounded "hoof" on top of the plane to put your hand on.  
Without that, gloves are necessary for scrubbing.

Regards,
John Lederer
Oregon, Wisconsin

Michael Campbell wrote:

>I picked up a cheap woodie coffin-type plane a bit ago and am
>considering making it into a scrub.
>
>How does one grind the camber into the iron?  It's, naturally, ground
>straight right now.  I'm not above using electrons for this, but is it
>sufficient for a scrub to mark the curve I want, then freehand it on
>the grinder, then sharpen?  Seems it would be, but wanted to get some
>more learned opinions.
>
>Archive: http://www.frontier.iarc.uaf.edu/~cswingle/archive/
>To unsubscribe or change options, use the web interface:
>    http://galoots.law.cornell.edu:81/read/?forum=oldtools
>
>  
>

Well, for my scrub plane, I took a very very modern Stanley #4 (first plane
I was given) and put a camber on the blade. It works like a charm and leave
the smoothing job for nicer example of #4 I have

My two cents

Bob in rainy Sherbrooke, Province of Québec

-----Message d'origine-----
De : John Lederer [mailto:john@j...]
Envoyé : 12 août, 2004 15:38
À : oldtools
Cc : oldtools
Objet : Re: [oldtools] making a scrub plane...

I think  I am idiosyncratic on this,  but for what it is worth:

My wooden scrub planes have arced  blade ends, but they also are rounded
on the edges of the sole and to a lesser degree across the sole.  Think
of the bottom of the plane being like the cross section of a banister rail.

This is functional.  By tilting the plane you can change the amount of
bite the blade takes.  It works naturally and well. Beats fiddling with
the plane in the middle of a scrub job.

I did not make them that way.  They came that way.  Crazy
German-Norwegian-Swedish-Finnish in our area.

A couple have a rounded "hoof" on top of the plane to put your hand on.
Without that, gloves are necessary for scrubbing.

Regards,
John Lederer
Oregon, Wisconsin

Michael Campbell wrote:

>I picked up a cheap woodie coffin-type plane a bit ago and am
>considering making it into a scrub.
>
>How does one grind the camber into the iron?  It's, naturally, ground
>straight right now.  I'm not above using electrons for this, but is it
>sufficient for a scrub to mark the curve I want, then freehand it on
>the grinder, then sharpen?  Seems it would be, but wanted to get some
>more learned opinions.
>
>Archive: http://www.frontier.iarc.uaf.edu/~cswingle/archive/
>To unsubscribe or change options, use the web interface:
>    http://galoots.law.cornell.edu:81/read/?forum=oldtools
>
>
>

>=A0Well, for my scrub plane, I took a very very modern Stanley #4 =A0
>=A0(first plane I was given) and put a camber on the blade. It works
>=A0=A0like a charm and leave the smoothing job for nicer example of #4
>=A0I =A0have

=A0I've done the same with a Record #4. =A0I don't think I can take as
=A0big a cut as with a plane with a more open mouth and heavier blade
=A0but then my muscles limit this to some degree as well.

>=A0My two cents

=A0Mine's only a CDN penny as Record planes aren't worth as much as
=A0Stanley planes :-)

>=A0Bob in rainy Sherbrooke, Province of Qu=E9bec

=A0Boy...that's for sure.

---
Cheers --- Larry Marshall
Qu=E9bec City, Qu=E9bec
http://www.woodnbits.com