Why you need a well cambered blade on a No7

[Jacob]

Temporarily without my combi machine, had to saw up some big bits of ply. https://www.ukworkshop.co.uk/thread...-well-in-your-work-bench.148868/#post-1751536
Then had to plane edges nice and square on 1/2"ply.
Run the no7 along but difficult to get dead square on - check with square - easy to get it slightly off.
To get it square just use the edge of the plane with the cambered tilt, one side or the other, to correct it.
Or you could tilt a non cambered plane iron to the same effect, but having the tilt built in is handier.

 

[Phil Pascoe]

Presumably the purpose of using a No.7 is to get something straight and flat (square if it's the remit)? Why use a curved blade?

 

[Derek Cohen (Perth Oz)]

Temporarily without my combi machine, had to saw up some big bits of ply. https://www.ukworkshop.co.uk/thread...-well-in-your-work-bench.148868/#post-1751536
Then had to plane edges nice and square on 1/2"ply.
Run the no7 along but difficult to get dead square on - check with square - easy to get it slightly off.
To get it square just use the edge of the plane with the cambered tilt, one side or the other, to correct it.
Or you could tilt a non cambered plane iron to the same effect, but having the tilt built in is handier.

The late David Charlesworth was a great proponent of using a cambered #7. Well, for everything. . I never got on with this set up for a #7. It makes sense to use down the centre of a board, where a very fine hollow can prevent a high spot causing a matched set of edges to rock. That was always David's focus. However, off centre, on edges, a camber leaves a fine hollow where it will be seen as a gap.

My preference is to steer the plane - not tilt it or angle the blade - but move the entire sole over and plane with just a small section of the blade. The aim is to keep the plane flat and remove the high spots. Once done, plane the centre until you get full width shavings.

This is with a straight blade. The other advantage is that one can use this set up for match planing, where you cannot do so with a cambered blade.

Regards from Perth

Derek

 

[RobNichols]

I think it depends on how thick the board is. I expect cambering works best on narrower boards.

Personally if I'm really struggling getting an edge square I'll put the board on top of another board lying flat on my workbench, put the plane on its side, and run the plane along side like that.

 

[Jacob]

The late David Charlesworth was a great proponent of using a cambered #7. Well, for everything. . I never got on with this set up for a #7. It makes sense to use down the centre of a board, where a very fine hollow can prevent a high spot causing a matched set of edges to rock. That was always David's focus. However, off centre, on edges, a camber leaves a fine hollow where it will be seen as a gap.

My preference is to steer the plane - not tilt it or angle the blade - but move the entire sole over and plane with just a small section of the blade. The aim is to keep the plane flat and remove the high spots. Once done, plane the centre until you get full width shavings.

This is with a straight blade. The other advantage is that one can use this set up for match planing, where you cannot do so with a cambered blade.

Regards from Perth

Derek

It's not so easy to plane a thin edge (say 10mm or less) dead square as you don't get the feel, as you would with something wider. So being able to correct it can be useful.

 

[Jacob]

I think it depends on how thick the board is. I expect cambering works best on narrower boards.

Personally if I'm really struggling getting an edge square I'll put the board on top of another board lying flat on my workbench, put the plane on its side, and run the plane along side like that.

....the shooting board idea but without the shooting board.

 

[Pabs]

I've found placing an overhang to the side of the more pronounced edge helps to bias the cut to the higher side
Dropping knob hand down to guide the plane along the reference face helps consistency and winding sticks (sometimes a double set).

Jointer is not cambered.

I do still struggle to get it done in minimal passes. Short bits like drawer parts I do on the shooting board

 

[owen]

Why not just cut the ply correctly in the first place and save yourself the bother?

 

[Derek Cohen (Perth Oz)]

It's not so easy to plane a thin edge (say 10mm or less) dead square as you don't get the feel, as you would with something wider. So being able to correct it can be useful.

Jacob, this is where a shooting board gets used. If not a shooting board, then raise the work piece on the horizontal and use the bench top as the shooting board.

Regards from Perth

Derek

 

[Sgian Dubh]

Run the no7 along but difficult to get dead square on - check with square - easy to get it slightly off.
To get it square just use the edge of the plane with the cambered tilt, one side or the other, to correct it.
Or you could tilt a non cambered plane iron to the same effect, but having the tilt built in is handier.

All my bench planes have slightly curved cutting edges, arced being the term I prefer, but cambered seems to be the preferred nomenclature of the majority. I essentially replicate your described methodology of using the curved edge of the no 7's iron to square a board's edge.

Funnily enough, I used to aim for a straight cutting edge for the iron on longer planes, e.g., numbers 5, 6 and 7 with a tiny bevel at each corner, and tweak the lateral adjustment in use to correct out of squareness of a board's edge, but it was kind of fiddly and a bit hit and miss. I gave that up 40 - 45 plus years ago and just went with the so-called cambered edge: good square board edge results are much easier to obtain.

On a side note, my smoothing plane and block plane irons have always been sharpened with a 'cambered' (curved, arced) profile, and I can't recall why I ever decided early on in my career that straight cutting edges on the longer planes was a good idea. Whatever the reason, at some point in the mid to late 1970s or early 1980s I decided I didn't like that approach and decided all standard bench planes were best optimised if the cutting irons were sharpened with an arced profile.

I actually agree with you about something ... and I've just seen pigs fly across the sky outside the window where I'm typing this! Wow. Slainte.

 

[Jacob]

Jacob, this is where a shooting board gets used. If not a shooting board, then raise the work piece on the horizontal and use the bench top as the shooting board.

Regards from Perth

Derek

Yes but it I just find it quicker and easier with the workpiece in the vice and using the shape of the camber. I'm a bit lazy!

 

[BentonTool]

Jacob, this is where a shooting board gets used. If not a shooting board, then raise the work piece on the horizontal and use the bench top as the shooting board.

Regards from Perth

Derek

Yes, Derek, exactly correct! That is what I would also do.
Assuming however, that he piece of plywood would fit on your bench.

All my bench planes have slightly curved cutting edges, arced being the term I prefer, but cambered seems to be the preferred nomenclature of the majority. I essentially replicate your described methodology of using the curved edge of the no 7's iron to square a board's edge.

Funnily enough, I used to aim for a straight cutting edge for the iron on longer planes, e.g., numbers 5, 6 and 7 with a tiny bevel at each corner, and tweak the lateral adjustment in use to correct out of squareness of a board's edge, but it was kind of fiddly and a bit hit and miss. I gave that up 40 - 45 plus years ago and just went with the so-called cambered edge: good square board edge results are much easier to obtain.

On a side note, my smoothing plane and block plane irons have always been sharpened with a 'cambered' (curved, arced) profile, and I can't recall why I ever decided early on in my career that straight cutting edges on the longer planes was a good idea. Whatever the reason, at some point in the mid to late 1970s or early 1980s I decided I didn't like that approach and decided all standard bench planes were best optimised if the cutting irons were sharpened with an arced profile.

I actually agree with you about something ... and I've just seen pigs fly across the sky outside the window where I'm typing this! Wow. Slainte.

On the topic of cambering a jointer plane blade: yes and no.
I am fortunate enough to have several jointer planes.
I camber the blade on one, and the other I sharpen true.
In that manner, I can use one to flatten the faces of boards without leaving ridges. The other I dedicate only for planing the ends or edges of boards.
If you only have one jointer, consider purchasing a spare blade and swapping them out as needed.
IMO, both have their appropriate applications.

 

[Jacob]

All my bench planes have slightly curved cutting edges, arced being the term I prefer, but cambered seems to be the preferred nomenclature of the majority.

Not sure where "cambered" came from. I think maybe nobody gave it a thought (or a name) and freehand honed blades just came out that way naturally.

.....

On a side note, my smoothing plane and block plane irons have always been sharpened with a 'cambered' (curved, arced) profile, and I can't recall why I ever decided early on in my career that straight cutting edges on the longer planes was a good idea.

A lot of not very good ideas were invented by various gurus and it takes some time to shake them off. Especially on the sharpening front which was more or less re-invented and made much more difficult.

....

I actually agree with you about something ... and I've just seen pigs fly across the sky outside the window where I'm typing this! Wow. Slainte.

I'm sure you've said the same thing more than once over the years!

 

[Jacob]

Presumably the purpose of using a No.7 is to get something straight and flat (square if it's the remit)?

Yes

Why use a curved blade?

Because that's how they come out the way I sharpen them.
Turns out to be useful! Also avoids tram lines on wider stuff.
The amount of curve you get on a thin edge is so minimal as to be invisible. Arguably could be useful as the hollow holds the glue and also means that the edges meet tighter. Much like undercutting on joint shoulders etc.

 

[Chubber]

My mentor, Carmelu Malia, in the shipwrights shop at HMS St Angelo, told me 'Don't move your grip or change the angle of the holding, just THINK about changing the angle, it will come square...'

This was a man who could cut square and true across a 10" board without pre-marking with a square and chafed me good-heartedly when I used a square on 2 x 1s.

Where do the years go?

 

[Sgian Dubh]

If you only have one jointer, consider purchasing a spare blade and swapping them out as needed.
IMO, both have their appropriate applications.

There's not a cat in hell's chance of me buying an extra blade with one sharpened straight and the other sharpened curved ... so that I can swap them in and out all depending on the task. I'm afraid that for me a curved sharpened edge is good for everything. Slainte.

 

[Sgian Dubh]

Not sure where "cambered" came from. I think maybe nobody gave it a thought (or a name) and freehand honed blades just came out that way naturally.

A lot of not very good ideas were invented by various gurus and it takes some time to shake them off. Especially on the sharpening front which was more or less re-invented and made much more difficult.

I'm sure you've said the same thing more than once over the years!

I've never paid much attention to 'gurus', Jacob. They came along some time after I went through basic training as a furniture maker which, I suspect, occurred before you made your first inroads into being a woodworker, even though you're quite a bit older than me.

It's probably true. I think we have agreed about things before. Slainte.

 

[Tortion-Stephen]

"Guru" : Good Understanding, relatively Useless...

Sorry, couldn't resist. I've learnt some tips from this thread. I have a #6 with a more obviously curved blade for aggressively chopping material away, but some of my standard blades have a whisper of additional pressure at each edge to, as Jacob said avoid tramlining.

Feel I need to re-state, I'm a gobsh**e and only playing at woodwork, it was a couple of generations ago, my family had talent.
Cheers for the tips,

Stephen

 

[BentonTool]

There's not a cat in hell's chance of me buying an extra blade with one sharpened straight and the other sharpened curved ... so that I can swap them in and out all depending on the task. I'm afraid that for me a curved sharpened edge is good for everything. Slainte.

I will readily admit that my planing skills fall short, even of my own impoverished standards, necessitating all manner of allowances to avoid frustration.

I am still at the stage where I have some difficulty planing the edge of (especially narrow) boards square.
This has become all the worse as I have aged, not having anything within six feet in focus (post cataract surgery).

I must therefore, at times, use compensatory techniques including planing edges on the horizontal with my bench as a reference, using shooting boards, and yes... on occasion, affixing a fence to my jointer ! I consider these practices to be a cane for my woodworking waddle!

Having a square blade is useful to me in this setting. I find it easier to square an edge with a square blade, and admire those with the skill to do so with a cambered blade (although I can also understand the advantage to using one!).
With a square blade, the entire width of the blade will produce a square edge. With a cambered blade, one has to get the blade placement just so...

All that being said, cambered plane blades totally transformed my woodworking/planing! I could not do without them!

 

[Sgian Dubh]

I will readily admit that my planing skills fall short, even of my own impoverished standards, necessitating all manner of allowances to avoid frustration.

I am still at the stage where I have some difficulty planing the edge of (especially narrow) boards square.
This has become all the worse as I have aged, not having anything within six feet in focus (post cataract surgery).

I must therefore, at times, use compensatory techniques including planing edges on the horizontal with my bench as a reference, using shooting boards, and yes... on occasion, affixing a fence to my jointer ! I consider these practices to be a cane for my woodworking waddle!

Having a square blade is useful to me in this setting. I find it easier to square an edge with a square blade, and admire those with the skill to do so with a cambered blade (although I can also understand the advantage to using one!).
With a square blade, the entire width of the blade will produce a square edge. With a cambered blade, one has to get the blade placement just so...

All that being said, cambered plane blades totally transformed my woodworking/planing! I could not do without them!

I say do whatever you need to do to get the results you want with the skills you have and the tools you use. I admit that I don't use any of the techniques you described, such as edge planing with shooting boards and using the surface of your bench to run the side of the plane along, attaching fences, and so on. I guess I've just got used to truing edges of boards with the edge sitting upright and running the plane along that edge and adjusting the plane's position left and right as needed and doing short or long strokes, also as needed. Slainte.