Any good reason NOT to camber plane blades?

[Will Blick]

I am considering cambering all my plane blades. I can't think of any reasons NOT to camber them. Sharp square corners IMO offer no benefits. Right?

[Peter Tremblay]

I think for bench planes your idea is good, but the amount of camber ought to vary based on the planes intended use. However, I also think there is one exception with a plane (or just an iron) that is specifically used for a shooting board. I think it would be best if that had very very little to no camber.

However for joinery planes, shoulder plane, plow plane, router plane, rabbet plane of any type, or a DT plane (I could be forgetting some type) the iron should be as flat as you can make it and usually the edge should be square to the sides, except the DT plane or a skew rabbet or... you see what I mean ;)

HTH
Peter

[gary Zimmel]

I agree. Bench planes no problem with a camber. The camber will make sure you don't get plane tracks. Block planes are a differnt story. All of mine I have been left flat. I will use the block planes to clean up things like tenons so I want a flat surface.

[Adriaan Schepel]

This question of cambering can turn into quite a lively little debate - as you may soon find out.

Probably the biggest area of contention is jointer planes. Some of us camber, others of us don't (I'm in the latter camp with jointers).

I imagine few people would camber their block plane blades. However, in a post dated 3/11/06, Chris Schwarz wrote on his blog about this. He took a tip from David Charlesworth about the value of cambering block plane blades; it's worth a read.

Happy cambering,
Adriaan

[Steve Hamlin]

Finishing planes are largely a matter of taste. I prefer straight. Perhaps if I worked more awkward timbers I'd come to appreciate a cambered smoother.

Until recently, all of my planes were straight bladed. Now, I appreciate a range of cambers on my roughing planes.

There's a fuzzy line between (what I treat as) try and jointer planes. The former is the plane I use to true a board edge, and so can be cambered or not, depending on preferred technique (I currently use straight, but want to learn the cambered approach, so I can make an informed choice.) The latter for me is both a finishing plane and a joinery plane (per Peter's great categorisation) and so I prefer straight.

If you have a couple of planes with overlapping capability, maybe camber one only. Then use both in the same role on a project - then go with the blade style you find youself unconciously reaching for at the end.

Cheers
Steve

[Louis Bois]

I sometimes *ease* the corners on straight blades as well...usually a few passes on the edge of a stone before final honing. It alleviates some of the "track" issues without going to a full camber.

[Don C Peterson]

After trying both ways, I'm pretty firmly in the camber camp, at least for bench planes and block planes. Shoulder, rabbet, plough, and router planes are straight.

Most of my cambered planes are very slightly cambered using an Odate plate, my #5 is much more aggressively cambered for use as kind of an intermediate scrub.

[Will Blick]

Thanks for your responses....I should have been more specific, I was referring to bench (#4) and jack planes....well, and jointer planes :-)

> Shoulder, rabbet, plough, and router planes are straight.


Yes, this makes perfect sense, due to their use.


So it seems for flat (face) planing, no one has a "strong" case against cambering. So that's a slam dunk.


For my jointer plane, I still see a camber as beneficial. As I see it, the only drawback might be when edge jointing...but even then, unless the camber is striking the wood, there is no drawback. The camber is small enough whereas on the inside corner, I can't see the camber hitting the wood. On the other side, I would have to be joint planing a 2" board for the the outside camber to be an issue. I can live with that minor risk, plus, I do have a power jointer.


From what I have read, the cambers should be very small, just enough to remove the sharp corners, I see no benefits to a larger camber.



> If you have a couple of planes with overlapping capability, maybe camber one only. Then use both in the same role on a project - then go with the blade style you find youself unconciously reaching for at the end.

Good point...in my case, i am using the Veritas line of Bevel Up, Bench, Jack and Jointer planes, so I have a bunch of blades which are interchangeable between planes.... So I could do what you propose, but for these 3 planes, I still can't think of a good reason to leave any of them non cambered. Of course, my shoulder, rabbet, bullnose, and chisel planes will all remain non cambered.

I am on the fence with my small Veritas BU block plane....but will probably leave that one non cambered also.

[Michael Gibbons]

I suppose that you could have 2 jointers,one cambered for flattening and another with straight blade for edge jointing. I figure most folks will not use a edge jointing plane for anything much wider then 2 '' Camber all your bench planes. Blocks leave straight.

[Pedro Reyes]

Will,

Just my thoughts, to each his own.

I "ease" the corners of my #3, #4, #4-1/2, and #5. No special roller, just with pressure during final honing.

While there may be no disadvantage (this could be argued) to cambering all blades (bench at least)... why do it? is there always an advantage? I don't usually face plane with my #7, so why go through the extra trouble? My #5-1/2 doubles as my shooting board plane and as a Jack, so not too concerned with tracks.

I prefer a straight edge on my jointers because so far I've always used the "clamp both boards" technique, maybe not good enough yet to plane a perfect 90 on an unsuported board. So in this case camber would work against me if pronounced enough.

Shoulder, Rabbet, Dado, Fillister, #50, et al, need straight edge IMHO.

peace

/p

[Don C Peterson]

Will,

Cambering is more than just rounding the corners, at least for me. The entire edge of the plane is rounded, very slightly to be sure, but still rounded over the entire witdth.

Even my jointer is cambered. David Charlesworth is a big proponent of this technique and at first I didn't really get what he was saying, but now I do and I find that edge jointing with a cambered iron is my preference.

[Pedro Reyes]

Don,

This could be a separate thread, but, while we are on the subject...

I have seen videos of David C. doing that, and it sounds cool, I also have vol 1 and 2 (good books).

But, please correct me if I'm wrong, when he is using that technique he is only doing one board at a time, right? And basically squaring it by taking advantage of the ability to take a slightly different depth of cut depending on where the plane is.

I joint with both boards clamped, so for me straight is easier, or does he use it for both boards at the same time (can't recall). How about you?

thanks.

/p

[Don C Peterson]

Pedro, you are correct. A cambered iron would NOT be the way to go with the two boards clamped side by side. I tried that method too, and just found that I have much better luck with the one at a time with a cambered jointer method. The biggest problem I had with the two board at a time method was that slight imperfections in the straightness of the joint are multiplied.

Since I have yet been able to shoot a PERFECTLY straight edge, doing one at a time leaves a bit of randomness to the imperfections and they at least have a chance of cancelling eachother out instead of mirroroing and magnifying each other.

[Wilbur Pan]

This is off the original topic, but I've found it very useful to plane boards for edge gluing with a sprung joint, so that there's a very very very slight concavity along the joint. This has helped me a lot with getting a tight glue line, and fixes a lot of the problems in getting a perfectly straight edge for panel glue ups.

But as far as non-cambered planes go, I don't put a camber on my block planes, shoulder planes, rabbet planes, router plane, or groove planes. All of my bench planes have cambers of varying degrees, with planes set up to take a finer shaving with less camber.

Putting a camber on a plane blade is easy. All I have to do is try to get a straight edge on my plane blade using my waterstones, and voila! Instant camber. ;)

[Seriously, cambering a plane blade is just a mater of taking extra strokes while putting pressure on the outside edge of the plane blade instead of the middle. More strokes = more camber.]

[Bob Oehler]

To camber or not to camber that is the question.
Most of the answers have been addressed here my personal is smoothing planes are lightly cambered. Jointers are not. Wood try planes are cambered fairly agressivly. And block planes you are just going to have to have enough to have some cambered and some not. It is just another way to get more planes to weight you down as you head down the slippery slope.

Plane On.
Bob O

[Pedro Reyes]

Don,

Thanks for your feedback, as always we all deal differently with the obstacles and still get good results. I hope one day I can learn your technique, (camber and single board).
I deal with the straightness issue just like Wilbur has indicated. After I get two nice continuous shavings (1 from each board) I start the cut say 5" from the end and finish it 5" form the other end, and so on maybe 2 or 3 times, always closer to the middle, and create that concavity. Sometimes I heavily skew the #7 to avoid it 'riding' over, I sometimes even take a #5 and plane that concavity (scold me if you must), to each his own.

Sorry to digress, I guess to apply this back to the original question. If you think you can joint an edge perfectly square to the face more easily than planing an edge straight, then camber, otherwise leave straight;)

/p

[Will Blick]

>While there may be no disadvantage (this could be argued) to cambering all blades (bench at least)... why do it? is there always an advantage?


not always an advantage...but it leaves less tracks and IMO, allows you to more easily have an angle attack on the board.... right?





> Cambering is more than just rounding the corners, at least for me. The entire edge of the plane is rounded, very slightly to be sure, but still rounded over the entire witdth.


This is correct.... I was considering chopping down the corners, more so than rounding the entire edge.... of course in the cambering process, the edge will no longer be straight....but maybe 1/64" would be a nice starting point?






> This is off the original topic, but I've found it very useful to plane boards for edge gluing with a sprung joint, so that there's a very very very slight concavity along the joint.

I remember reading this....the center is sprung outward, right? Can't remember the logic behind why this helps the glue line....




> If you think you can joint an edge perfectly square to the face more easily than planing an edge straight, then camber, otherwise leave straight

I keep reading this, but don't understand your point, could you elaborate?

[Pedro Reyes]

>
not always an advantage...but it leaves less tracks and IMO, allows you to more easily have an angle attack on the board.... right?

True, but usually you don't always plane on the face.



> This is off the original topic, but I've found it very useful to plane boards for edge gluing with a sprung joint, so that there's a very very very slight concavity along the joint.

I remember reading this....the center is sprung outward, right? Can't remember the logic behind why this helps the glue line....

No, you want the center inward, an exageration would be two boards would be touching just at their ends and a gap in the middle. The logic is you clamp in the center and the boards are tight all throughout, and specially the ends are tight.

> If you think you can joint an edge perfectly square to the face more easily than planing an edge straight, then camber, otherwise leave straight

I keep reading this, but don't understand your point, could you elaborate?


Well, you would have to watch or read David Charlesworth's technique on edge jointing with a cambered edge (sorry don't mean to dismiss you)... Basically David states that planing a 90 degree edge (to the face) is easier done with a camber, and this is most likely true. If you master this you only have to worry about a straight edge (end ot end).
Planing an edge straight, has more to do with the plane riding up and down on the edge, but planing an edge straight does not guarantee you got it to a perfect 90 to the face.
However if you clamp two boards which are about to be jointed, getting a perfect 90 is not an issue, because the angles between the boards will complement each other into a perfectly flat joint. All you have to worry is a straight edge (end to end).

That said, depending on what you think you are more proficient at, chose camber vs no camber.

Hope this helps, but I'd be happy to elaborate.



/p

[Will Blick]

> However if you clamp two boards which are about to be jointed, getting a perfect 90 is not an issue, because the angles between the boards will complement each other into a perfectly flat joint.

Agreed Pedro....but using this 2 board technique, I assume now, a straight blade is preferable, right?

Also, if you use a fence....

http://www.leevalley.com/images/item/woodworking/planes/05p3701s3.jpg


Then I would assume:

1) straight edge blade is surely more desirable

2) no need for tandem board method (assuming a reliable plane bottom and fence.

Of course, I am not discounting the value of the tandem board method, as I appreciate its self correcting potential. However, this method IMO, is not as self correcting as a TS l/r miter cut. As with the tandem edge plane method, only fully symmetrical errors will self correct. Humans are not as perfect as a TS blade and miter fence, so you can occasionally get non symmetrical errors.

So I would think, if you have a true 90 on the jointer plane fence, you have a better chance of a perfect glue joint - and, it's easier and faster....and you can do one board at a time. Would you agree with this assessment?

Also, for edge jointing with a jointer plane, I really don't understand why a camber would be beneficial, as the slight concave of the blade will product non flat surfaces.... is there a Charlesworth video link that explains this, or can you explain the theory behind this?

[Randy Klein]

Also, for edge jointing with a jointer plane, I really don't understand why a camber would be beneficial, as the slight concave of the blade will product non flat surfaces.... is there a Charlesworth video link that explains this, or can you explain the theory behind this?

The concavity is very, very slight and over a 1" board is, for all intents, flat.

The benefit is that you can use the camber to correct for non-square edges by choosing how the cambered blade is presented to the piece. e.g. If the edge is high on right side, you would put the center of the blade more to the right and it will take a slightly deeper cut than the left.