# I don't get why all plane irons aren't laminated?



## ali27 (16 Jan 2012)

Only the edge of the plane iron does the cutting, so why would the whole
iron be made from the same steel? Makes sharpening a lot tougher and time
consuming. Why not a very thin layer(0.5mm or so) of tough steel(A2,M2,HSS)
at the cutting edge laminated or glued with very soft steel or even aluminium?







Something like that.

I know they do this with japanese plane blades. If I had to guess why this 
isn't done with western plane blades, I'd think it's too expensive. What about
just gluing some soft steel of 3mm thick above a very thin tough steel?

Thanks


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## Mike Wingate (16 Jan 2012)

Quite a few of the old tyme blades were laminated. Hammer forged.


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## bugbear (16 Jan 2012)

it's a cost play-off between the saving on high grade edge-holding steel, and the cost of the laminating process.

BugBear


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## ali27 (16 Jan 2012)

Ok, so cost is an issue. What about just glueing a very thin tough steel with a much 
softer steel or maybe even aluminium? Why isn't this done?


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## TheTiddles (16 Jan 2012)

That kind of glue hasn't been around for more than a few years, diffusion bonding would be a better way, how thin should the hard bit be? I'd say at least 2mm to allow a decent size second bevel, that's heading towards a full thickness of blade for an old blade.

Aidan


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## Jacob (16 Jan 2012)

ali27":3lrc42rg said:


> Only the edge of the plane iron does the cutting, so why would the whole
> iron be made from the same steel? Makes sharpening a lot tougher and time
> consuming. Why not a very thin layer(0.5mm or so) of tough steel(A2,M2,HSS)
> at the cutting edge laminated or glued with very soft steel or even aluminium?
> ...


Cost. 
But the need for it has been designed out by Bailey - his whole design turns around the thin non-laminated blade and how to make it work as well as a heavy bladed woody. Result; cheaper (blade, not plane), easier to sharpen, easier to remove /replace/set/adjust, and works a whole lot better than a wooden plane with a laminated blade.
It still needs a good deal of stiffness so 0.5mm steel on aluminium wouldn't have the strength I guess.
A very similar design to the Bailey plane is the Gillette safety razor, where the stresses are different and an even thinner blade is possible. Don't know which came first, or was it a case of great minds thinking alike?


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## bugbear (17 Jan 2012)

Jacob":1flrdyha said:


> But the need for it has been designed out by Bailey - his whole design turns around the thin non-laminated blade...



The tool historian in me feels obliged to point out that both Stanley and Record used laminated blades in their Bailey planes for a long period.

It may be of interest to some to quote what Stanley say:

"The cutting edge portion is a very high carbon crucible steel of a
compositon particularly suited to hold a keen edge. The remainder of the
Cutter is a lower carbon steel and it acts as a backing for the hard
cutting edge. Both parts are welded together when originally cast in the
ingot and cannot be separated."

And (from OLDTOOLS) we find:






BugBear


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## ali27 (17 Jan 2012)

Jacob":15kzg666 said:


> ali27":15kzg666 said:
> 
> 
> > Only the edge of the plane iron does the cutting, so why would the whole
> ...



Jacob, wouldn't glueing the 0.5-1mm to lets say a 4mm thick aluminium or very soft steel
provide enough stiffness? I was under the impression that glueing a 0.5-1mm thick piece
of steel to steel of 4mm would give the stiffness of something around a 4mm thick piece
of steel.

Ali


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## Jacob (17 Jan 2012)

I think that once down to a certain thickness there's little point in laminating, which will be why Stanley dropped it I guess.

PS or to look at it another way - the conventional set-up already _is_ laminated - the blade "unit" consists of frog/blade/cap iron/lever cap; four lamina all held together by a bolt, rather than being welded or glued.


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## ali27 (17 Jan 2012)

Jacob":1vz434tv said:


> I think that once down to a certain thickness there's little point in laminating, which will be why Stanley dropped it I guess.
> 
> PS or to look at it another way - the conventional set-up already _is_ laminated - the blade "unit" consists of frog/blade/cap iron/lever cap; four lamina all held together by a bolt, rather than being welded or glued.



Jacob you have a point here, but how do explain then the improved performance
when using thicker replacement blades? Many people claim this after they
switch to veritas,hock, clifton or qiansheng blades which are thicker. Even without 
changing the blade, but using a thicker chip breaker there is improved performance.

I would like to try this idea and then ditch the chipbreaker as a bonus. 0.5-1 mm
high carbon,a2 or HSS steel plate glued to 4mm thick very soft steel or even
aluminum. Cut a slut on it for the yoke and ditch the chipbreaker.


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## Jacob (17 Jan 2012)

People get enthusiastic about all sorts of things and fashions come and go. Personally I haven't tried a thicker chip breaker, though I have tried different blades, a Hock and a Smoothcut, both in no 4s or 5s. They are good yes, but so is the standard blade. When you are actually head down and planing I don't think there is much difference. The Hock keeps an edge longer (I think) but takes longer to sharpen.
Basically I'm sceptical about all the mysterious and magical alternatives on offer and I have put a little effort into trying some of them.

PS virtually the whole point in having a chip breaker (so-called) is to permit the use of a thinner blade. It keeps the blade pinned tight against the frog so that it will function as well as a trad thick blade. By all means turn the clock back if you want to, but then sharpening will take longer, blades cost more, etc etc.


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## Paul Chapman (17 Jan 2012)

Unless you hone the whole of the bevel, sharpening a thick blade takes no longer than sharpening a thin blade. That's why most people use a primary bevel and a secondary bevel - it's only the small secondary bevel that is honed when re-sharpening the blade.

Cheers :wink: 

Paul


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## bugbear (17 Jan 2012)

Jacob":b7gsp6mn said:


> PS virtually the whole point in having a chip breaker (so-called) is to permit the use of a thinner blade. It keeps the blade pinned tight against the frog so that it will function as well as a trad thick blade.



Woodies and infills, both of which have very thick blades ALSO have chip breakers (sometimes called cap irons). If the purpose of cap irons were to allow thin blades, planes with thick blades wouldn't have them, but they do.

BugBear


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## ali27 (17 Jan 2012)

Paul Chapman":2s9eyut6 said:


> Unless you hone the whole of the bevel, sharpening a thick blade takes no longer than sharpening a thin blade. That's why most people use a primary bevel and a secondary bevel - it's only the small secondary bevel that is honed when re-sharpening the blade.
> 
> Cheers :wink:
> 
> Paul



Yes I am aware of this and use it myself. However the microbevel gets
bigger everytime you sharpen and after 5-6 times you need to go to the
grinder. You can microbevel with my idea as well and have a much easier
task when going to the grinder as the aluminium or soft steel upper layer
is much easier to grind. The aluminium would probably be easily removed
on a waterstone.

It just doesn't make sense to have a 3mm thick plane iron with 2-2.5mm of 
tough steel which does not do anything more than provide stiffness. The only
required toughness is at the edge.


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## bugbear (17 Jan 2012)

ali27":1yhs81c4 said:


> Yes I am aware of this and use it myself. However the microbevel gets
> bigger everytime you sharpen and after 5-6 times you need to go to the
> grinder. You can microbevel with my idea as well and have a much easier
> task when going to the grinder as the aluminium or soft steel upper layer
> is much easier to grind.



Bench grinders go through even hardened tool steel on the primary bevel more than quick enough for me - I'm not concerned about saving the labour of a power tool!

Making a laminated blade is a complex enough process that the costs might exceed the benefit - the only laminated blade I know of outside traditional Japanese ones if the Smoothcut/Samurai one.

Historically, it was more common, with European woodie plane blades being laminated (pretty much universally), and (as I mentioned before) Bailey blades from Record and Stanley being laminated for an extended period.

There is a saving on the high grade steel, so it's to do with materials costs versus process costs.

The performance advantages of lamination have been (heatedly) discussed on forums before. You might want to ask yourself wether the soft layer is providing mass, stiffness or both.

BugBear


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## Jacob (17 Jan 2012)

Paul Chapman":a8saiqvb said:


> Unless you hone the whole of the bevel, sharpening a thick blade takes no longer than sharpening a thin blade. That's why most people use a primary bevel and a secondary bevel - it's only the small secondary bevel that is honed when re-sharpening the blade.
> 
> Cheers :wink:
> 
> Paul


However you do it, all the bevel has to be attended to. There are no short cuts. Honing or grinding; it's all re-sharpening. The advantage of a thin blade is that you can do it all by hand quite easily.



ali27":a8saiqvb said:


> .... the microbevel gets
> bigger everytime you sharpen and after 5-6 times you need to go to the
> grinder. ......


Only if you choose to do it that way. This has always struck me as very inefficient.
No reason why you shouldn't back off on a coarse grit and hone on a fine grit , every time you sharpen. Or with a thin blade you can do both on a moderately fine grit, in one operation; either as two bevels, one flat bevel, convex bevel, or any other arrangement you fancy!


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## bridger (17 Jan 2012)

laminating aluminum to steel is going to have problems. their working temperatures are different enough to preclude welding processes, and they have different enough thermal expansion rates that even if you could glue them together you'd have problems keeping the resulting blade flat. besides, abrasives that work for steel will gum up quickly used on aluminum.


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## Sawyer (17 Jan 2012)

Just what I was about to say, Bridger!
Aluminium may be soft, but put it anywhere near your grinder and the stone will quickly resent it by clogging up. What time you save will be lost on dressing the grindstone, which, being clogged, will probably have overheated and blued the tool steel too. #-o 

I once restored an old wooden jack with a very thick laminated blade: chipped, so I had to regrind it - it took forever! With a thin blade, the same thing would have taken about one minute.


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## Richard T (20 Jan 2012)

Welding tool steel to wrought iron is an art in itself anyway - steel has a lower welding temperature than iron. If anyone has tried forge welding, you'll know how difficult it is to get two pieces of metal with the same welding temps together ..
Yet generations of Sheffield smiths put blades together like this day in, year out. Not just plane irons either, everything: axes, adzes, billhooks, scythes, all plated or Sandwiched. All because crucible steel could only be made in small quantities. 
Though lamination has the advantage of the iron supporting the steel from cracking when quenched and when left harder after tempering than would be advisable if it were the same hardness front to back. The Japanese play on this to the extreme with those huge lumps of soft iron with insanely hard steel on the front. 
Not sure how much the Brit irons were left "over" hardened but I have some old'uns that are pretty much like trying to grind glass, ... so maybe. 
All in all Ali, I really don't think that gluing very hard thin stuff to very soft thick stuff would work ..... for long.


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## Benchwayze (21 Jan 2012)

ali27":3rttr5sf said:


> Jacob":3rttr5sf said:
> 
> 
> > I think that once down to a certain thickness there's little point in laminating, which will be why Stanley dropped it I guess.
> ...



I know some experts who would disagree that thicker blades are better and hold an edge longer. (They usually employ both though.) 
So do I and although no expert, in the guru sense, I prefer the thicker blades. They take longer to sharpen, and need two or three honing sessions from new, to get the ultimate edge. But I find the edge lasts longer; depending on the species of timber you are working with, of course. I usually give my planes and chisels a good hone before I start a new project. (Which has been some time since mind! :mrgreen: )

The idea behind laminated blades was explained to me some time ago. This is how it was explained. 
The quality of steel required to hold a good edge is expensive to produce, and a thicker blade was less inclined to 'chatter'. So the best of both worlds was to laminate the blade; a veneer of good steel for the edge, backed up by lesser quality to get the stiffness. Maybe that applied to wooden planes initially, as most of my laminated blades came from old 'woodies'. I have had Baileys with thin irons chatter on me, but usually because they were not set up properly, or the iron was blunt. Even so I still prefer a thicker blade. But maybe that's just me. :wink: 
John


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## Vann (22 Jan 2012)

I guess that laminating a thin layer of "good" steel to a backing layer of mild steel, using a high quality glue (epoxy?) would work. The only problem I see would be in grinding the bevel - too much heat would cause the epoxy bond to soften (i.e. much lower heat than required to blue the iron would soften the bond).

If I were you I wouldn't try aluminium for the backing - at least not until I'd tested the theory with a mild steel backing - it's a step too far IMHO.

As for eliminating the cap-iron: you'd need a series of yoke slots down the iron or else total usable iron would be too short.

Cheers, Vann.


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## Benchwayze (22 Jan 2012)

I didn't say 'gluing' Vann. I was referring to the method where the two steels are forged together whilst hot. 

Can't say I trust epoxy or aluminium quite that much!

John


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## Vann (22 Jan 2012)

Hi John,

Sorry, I was comment on ali's original suggestion, rather than your post.

Cheers, Vann.


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## Benchwayze (22 Jan 2012)

Not a problem Vann. 
I have a couple of rusty planes BTW. 
Taking up space. :mrgreen: 

John


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## Vann (23 Jan 2012)

Benchwayze":3cne4jdf said:


> I have a couple of rusty planes BTW.


Wot, only a couple? :mrgreen: 

Cheers, Vann.


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## Benchwayze (23 Jan 2012)

Vann":2eyz70hp said:


> Benchwayze":2eyz70hp said:
> 
> 
> > I have a couple of rusty planes BTW.
> ...





'Couple' is a euphemism for too many Vann! :mrgreen: 
John


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## bugbear (23 Jan 2012)

Benchwayze":3t0fhgq1 said:


> 'Couple' is a euphemism for too many Vann! :mrgreen:
> John



As in "I had a couple of beers last night..."  

BugBear


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## Benchwayze (23 Jan 2012)

bugbear":17v491zr said:


> Benchwayze":17v491zr said:
> 
> 
> > 'Couple' is a euphemism for too many Vann! :mrgreen:
> ...



Me? :-s Never! :---)


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## matthewwh (23 Jan 2012)

Hi Ali,

In 1855 Henry Bessemer invented the blast furnace which turned the lengthy, inaccurate and expensive process of making steel into a fast, accurate and cheap one. This was the change that first made it cheaper to produce the whole blade out of good steel than laminate it.

Since then the cost of producing steel has fallen and the cost of skilled labour has risen - which is why hand forged Clifton plane irons are dearer than ones lasered out of gauge plate. 

There are still Smiths about who make laminated blades, most of them producing bespoke knives where the market is prepared to bear the cost of their skills.


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## bugbear (24 Jan 2012)

matthewwh":132jf84e said:


> Hi Ali,
> 
> In 1855 Henry Bessemer invented the blast furnace which turned the lengthy, inaccurate and expensive process of making steel into a fast, accurate and cheap one. This was the change that first made it cheaper to produce the whole blade out of good steel than laminate it.
> 
> ...



Samurai/"Smooth Cut" are factory making laminated Bailey blades.

http://www.axminster.co.uk/samurai-japa ... prod22303/

(those used to be cheap - what happened?!)

BugBear


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## Jacob (24 Jan 2012)

bugbear":3hrb8b45 said:


> matthewwh":3hrb8b45 said:
> 
> 
> > Hi Ali,
> ...


I bought one a bit back - I thought it was £20 ish.
They probably are a bit faster to hone by hand but I haven't noticed any real difference from the normal Record blade. 
Pointless really. They are just cashing in on the enthusiasts market. You'd have to put in many hours of work side by side to notice any meaningful difference. No point in paying £40 to replace a blade which came free with your plane, unless there is a tangible quick return.


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## bugbear (24 Jan 2012)

Jacob":117telow said:


> bugbear":117telow said:
> 
> 
> > matthewwh":117telow said:
> ...



When I bought one in (google) 1999 (!), I found that it took a much finer edge than the even the best (laminated) Record blades, and held it longer.

This is what you'd expect from harder steel. It's also easy to hone, (since the bevel is partially soft metal). Flattening and polishing the back revealed just how hard the edge-steel is.

On a historical note, Record went back to their laminated blades in their short lived cs88 model, and Roger Buse did a "tuned bailey" plane with a laminated blade in the mid 80's.

BugBear


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## Vann (24 Jan 2012)

Jacob":1lj5yx3w said:


> Pointless really. .... No point in paying £40 to replace a blade which came free with your plane, unless there is a tangible quick return.


Or you've bought a second hand plane with pitted/worn-out iron that needs replacing anyway...

Cheers, Vann.


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## Jacob (24 Jan 2012)

Vann":3pwxitfe said:


> Jacob":3pwxitfe said:
> 
> 
> > Pointless really. .... No point in paying £40 to replace a blade which came free with your plane, unless there is a tangible quick return.
> ...


Buy another one - still cheaper than a smoothcut blade.

The thing about "holding an edge better/worse" I've never been able to find. If I sharpen any two blades the same way and for long enough then they seem always to be equally sharp, at first at least. 
What I have noticed (I think) is that harder edges will chip sooner. Quite quickly in fact - but sometimes leaving hardly any visible sign but just that slight feeling of fine ridges when you slide a finger over the wood.
I just verified this once again, this morning. I've been wondering which of two 5 1/2 planes to sell. One has an old Millers Falls blade . It was chipped when I got it so I ground it back and it was obviously harder than a standard Record blade. But it chipped again in normal use on a hard bit of sycamore. Very fine chips. It's gotta go!


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## Benchwayze (24 Jan 2012)

Why not just buy a new blade Jacob? A sharp 5 1/2 is always useful to have at hand. :?:


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## Jacob (24 Jan 2012)

Benchwayze":eegb4kxd said:


> Why not just buy a new blade Jacob? A sharp 5 1/2 is always useful to have at hand. :?:


Yes alright then. Except if you buy a 2nd plane you can probably dump the first one on ebay and get your money back.


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## Benchwayze (24 Jan 2012)

Jacob":38x6o7sn said:


> Benchwayze":38x6o7sn said:
> 
> 
> > Why not just buy a new blade Jacob? A sharp 5 1/2 is always useful to have at hand. :?:
> ...




Ahhh! I thought you were considering selling the plane, because the iron was not too good.


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## Jacob (24 Jan 2012)

Benchwayze":3khq7p10 said:


> Jacob":3khq7p10 said:
> 
> 
> > Benchwayze":3khq7p10 said:
> ...


Sorry yes, crossed wires. I am selling the plane. I only want one 5 1/2. I'm doing a bit of a clear out, some 5s as well, and other stuff.


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## Benchwayze (24 Jan 2012)

NP Jacob!

I have a few 5s I ought to offload. Stanleys and Records. It's just getting around to sorting them out! :?


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## János (24 Jan 2012)

Hello,

The fabrication of hardenable steel was a very laborious process before the invention of modern steel furnaces (Siemens, Bessamer etc.). The iron was hand-forged, and heated in coals to absorb carbon, and produce useable steel. The work of XVIIIth century British inventors, like the Cranage brothers and Henry Cort made possible the production of larger batches of quality iron and steel, but cheap cast steels become available only in the second half of the XIXth century. Laminating, forge-welding or even hard soldering steel to an iron backing or tang was a common means of sparing costly steel. 
As a byproduct of lamination, the blades edge could be hardened to a higher hardness, over 60 HRC, without danger of breakage or cracks. In the XXth century the new developments of metallurgy created the different kinds of high alloy tool steels. These steels combined hardness with toughness: laminating a molybdenum or wolfram steel to soft iron would be insane.
Well made modern irons are as good as laminated carbon steel ones. As far as I know that, laminated blades are still produced in Germany and Austria for traditional wooden planes.
And a word about cap/breaker/double irons: the purpose of this invention is the improvement of cutting performance and surface quality left by the blade, through altering/modifying the cutting geometry. A properly set double iron behaves like a higher pitched blade, but the cutting force remains almost the same. Improved rigidity is a mere bonus.

Have a nice day,

János


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## Jacob (24 Jan 2012)

János":2wsqcjd7 said:


> ..........
> And a word about cap/breaker/double irons: the purpose of this invention is the improvement of cutting performance and surface quality left by the blade, through altering/modifying the cutting geometry. A properly set double iron behaves like a higher pitched blade, but the cutting force remains almost the same. Improved rigidity is a mere bonus.
> 
> Have a nice day,
> ...


So would a cap iron improve the cutting performance of a bevel up plane, through altering/modifying the cutting geometry? And if not, why not?
NB it's not "rigidity" that's the issue IMHO. It is the firm grip near the edge, pinning the blade to the frog and back of the mouth. Amounts to the same thing I suppose.


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## bugbear (25 Jan 2012)

Jacob":3tq93bu6 said:


> János":3tq93bu6 said:
> 
> 
> > ..........
> ...



I don't immediately see any way to get the cap-iron to sit ON THE BEVEL to get it close enough to the edge to effect cutting.

And (God forbid) such a design would appear to require a consistent bevel over time. :wink: :wink: :wink: 

BugBear


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## Jacob (25 Jan 2012)

bugbear":17xs9n85 said:


> Jacob":17xs9n85 said:
> 
> 
> > János":17xs9n85 said:
> ...


Same as an ordinary one but with bit of an extra long curl at the end?
My point was that I don't think it'd have any effect and Janos's theory is wrong. 

Confident statements abound, in woodwork fora as elsewhere. They should be received with some scepticism. I've just been googling "cult of expertise". :shock:


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## Corneel (25 Jan 2012)

I have some older woodies with a single blade, bedded at 45 degrees. They are definitely more tearout prone then the other planes with chipbreaker. At the other hand, for me, the chipbreaker isn't the end-all solution against tear out. A higher pitched blade works better in that area.

So for smoothers a 50 degree bedded plane is a good investment ( I paid about 10 euro for my Ulmia Reform smoother). The real problem is with the other planes like the jacks, fores and jointers. A 45 degree angle is very nice to have, because it takes less energy to push the plane. And higher pitched ones are very rare or very expensive. In that kind of plane a chipbreaker helps to reduce the amount and depth of the tear out, making it easier to get the board smooth with the smoother. 

Cambered blades aand chipbreakers are another problem. So i'm thinking about making a nice wooden jackplane with a single blade and 50 degree angle.


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## bugbear (25 Jan 2012)

Jacob":1m7zjx2x said:


> János":1m7zjx2x said:
> 
> 
> > ..........
> ...



The effect of cap irons on cutting geometry (and results) has been confirmed experimentally (by an diligent and careful Japanese scientist), although the distance from the cap iron to the cutting edge needs to be rather small.

BugBear


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## Jacob (25 Jan 2012)

bugbear":ar66mj2n said:


> .....
> The effect of cap irons on cutting geometry (and results) has been confirmed experimentally (by an diligent and careful Japanese scientist), although the distance from the cap iron to the cutting edge needs to be rather small.
> 
> BugBear


Link?
This sort of idea? http://www.leevalley.com/en/shopping/in ... px?p=48492
So would it work on a BU plane (yes it'd have to be turned a bit to sit on the bevel in an equivalent position)?
I guess it might, but that for most planes it is set back too far and it's primary purpose is the edge hold down, not needed so much on a heavy bladed steel BU plane.
When I've tried a very close set cap iron it has hindered rather than helped. To be realistic it'd have to be not only close but also very carefully shaped and fitted to match the curled turned edge of a scraper blade. IOW a perfect detail, hypothetical possible, not practical.
Having said that I'll try again!


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## bugbear (25 Jan 2012)

Jacob":6ace6k94 said:


> it'd have to be not only close but also very carefully shaped and fitted to match the curled turned edge of a scraper blade.



The angle you're thinking of (to turn up and break the shaving) is made between the edge of the cap iron and the back of the blade in a BD plane.

No fancy shaping is needed.

Edit; here's my "how to tune a cap iron" picture again:







Top image shows clearly shows how the cap iron would turn the shaving up at a steeper angle than the blade.

BugBear


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## Corneel (25 Jan 2012)

Yes it's finicky. But it saves energy when pushing the plane and it leaves a nicer finish.

Regarding the finickyness, it helps to set the capiron a bit further from the edge, fasten the screw and then set the capiron to the required position with a small hamer.


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## Jacob (25 Jan 2012)

bugbear":1nnr5aln said:


> Jacob":1nnr5aln said:
> 
> 
> > it'd have to be not only close but also very carefully shaped and fitted to match the curled turned edge of a scraper blade.
> ...


My point was that to fit a cap iron to a BU blade you would need to shape it to reach over the bevel to the edge. I doubt anybody would bother, even in the interests of plane science! But if it works for a BD blade it should work the same for a BU blade, the EP angle being the same in each

I've just had a go with a closely set cap iron <0.5mm on a BD plane. It doesn't _improve_ the cut particularly it just changes a fine cut into something approaching a scrape, which is what you'd expect. It also makes a deep cut much harder work. No point really. The normal 1/16" is fine.

PS I get the opposite effect that Corneel gets i.e. more work not less. :shock:


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## bugbear (25 Jan 2012)

Jacob":3nivo6qf said:


> I've just had a go with a closely set cap iron <0.5mm on a BD plane. It doesn't _improve_ the cut particularly it just changes a fine cut into something approaching a scrape, which is what you'd expect. It also makes a deep cut much harder work. No point really. The normal 1/16" is fine.



Any of the old texts will point out that a cap iron very much closer than the shaving thickness will cause trouble, probably jams. Adjusting cap iron gap appropriately is part of correct plane setup.

The close fits are for tear out reduction when taking fine cuts on tricky wood - it's a cost-benefit thing, since getting everything working with a close fit cap iron is finicky.

Horses for courses.

BugBear


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## János (25 Jan 2012)

Dear Jacob,

You misunderstood something: I have never ever seen a bevel up plane with cap iron. In metallic bevel up planes there is a so called lever cap, but that is not the same thing (as you surely know that :wink: ). The development of double irons in traditional, bevel down planes is far from being well documented, but the bevel up plane configuration itself was a late XVIIIth, early XIXth century development. 
The effect of chip breakers in woodcutting tools was researched and documented by German, Russian and American scientists of the late XIXth early XXth century. Unfortunately, my books on woodworking tool theory are in my native language. 

A fast search of the web resulted in this:

http://ir.library.oregonstate.edu/xmlui ... sequence=1
http://woodtools.nov.ru/mag/understandi ... ood_id.htm

And Holtzapffel mentioned double iron planes in his magnificent opus:

http://www.wkfinetools.com/hUK/Holtzapf ... -Vol.2.pdf

The name “chip breaker” is a misnomer, tough: it was borrowed from metalworking terminology. In a handplane the breaker iron seldom breaks the shaving into chippings (a very heavily set /2~3 mm cutting depth/ plane can produce these fragmented chips, however) but abruptly bends it over instead, crushing the internal structure of cellulose fibres forming the cell walls.


Have a nice day,

János


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## Jacob (25 Jan 2012)

János":qt8hvlc4 said:


> Dear Jacob,.......I have never ever seen a bevel up plane with cap iron.
> ........


Nor me. But if it works for a bevel down plane (improves cutting, nothing to do with rigidity etc) it should work the same for a bevel up plane (with the same effective angle). So why is it not done?
Don't think I've misunderstood anything so far!


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## János (25 Jan 2012)

Dear Jacob,

Perhaps, because it would be quite pointless and impractical, I think, just like welding a hardtop to a Ferrari spider. But in theory, it would work flawlessly. 

Have a nice day,

János


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## ali27 (25 Jan 2012)

Thank you everybody for the responses. 

I think I have seen quite a few expensive BD infill planes without
chipbreaker that work excellently, which shows that the chipbreaker
is not needed.

For me an ideal plane blade is lamnated and is rigid enough
to not need a chip breaker. 

Ali


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## Corneel (25 Jan 2012)

JacobI've just had a go with a closely set cap iron <0.5mm on a BD plane. It doesn't [i:1i73zdnz said:


> improve[/i] the cut particularly it just changes a fine cut into something approaching a scrape, which is what you'd expect. It also makes a deep cut much harder work. No point really. The normal 1/16" is fine.
> 
> PS I get the opposite effect that Corneel gets i.e. more work not less. :shock:



I wonder at what angle the front of your chipbreaker is? If that is too steep I can also imagine the results you got.

But I won't argue too much because I am absolutely no chip breaker expert. I just feel that a close fitting chip breaker gives better results without increasing the workload.


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## bugbear (26 Jan 2012)

Jacob":2ex4apwg said:


> János":2ex4apwg said:
> 
> 
> > Dear Jacob,.......I have never ever seen a bevel up plane with cap iron.
> ...



Because nobody's come up with a way to fit one that works well enough to justify the cost and effort. In any case, with a BU design, it's easy to increase the effective pitch, which achieves a similar end result.

BugBear


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## Jacob (26 Jan 2012)

bugbear":3m00zc2a said:


> Jacob":3m00zc2a said:
> 
> 
> > János":3m00zc2a said:
> ...


Easy peasy - they just haven't tried. 
Mainly because there would be no point - BU blades are always heavy and firmly held down so they don't need the extra hold-down effect of the cap iron.
There would be a point if the cap iron actually did improve cutting in other ways as Janos says they do, but they don't.


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## bugbear (26 Jan 2012)

Jacob":3p7y7vd5 said:


> Easy peasy - they just haven't tried.
> There would be a point if the cap iron actually did improve cutting in other ways as Janos says they do, but they don't.



If you have an idea to make such a cap iron, put up a sketch - I've already explained why it isn't done in practice, the cost-benefit doesn't work out.

Evidence in favour of the cap-iron effect on cutting has already been cited.

BugBear


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## Vann (26 Jan 2012)

Jacob":2f1orjms said:


> ...*BU blades are always heavy *and firmly held down so they don't need the extra hold-down effect of the cap iron.


Not so. My Stanley and Record block planes (#110, #0120) are bevel up, and have irons as thin as, or thinner than, my bevel down planes from the same makers. I.e. less than 2mm thick.

Cheers, Vann.


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## dunbarhamlin (26 Jan 2012)

Given the plethora of weird and wonderful plane related patents, I'd be surprised if a chip breaking cap iron hadn't been devised for a BU plane - there's a fellow who posts on WoodNet who's catalogued a lot of these - could anyone summon up the energy, could be worth posting there (with patent in the subject to attract the fish  )


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## Richard T (26 Jan 2012)

I think it is to do with the low angle of the BU iron. Just by its lower angle it is much less likely to chatter than a BD at its steeper frog angle. 
Even though (Jacob wrote) "the EP angle being the same in each". - you can pare with a chisel BU no probs but you'd have a game trying to pair with one BD .... at least I would ... couldn't hold it. And the plane has more trouble holding it too. A BU iron has its flat side drawn into the wood, pulling it tightly against the inside of the plane sole, like any sided blade pulls in. The BD is apt to bounce. 
I guess this is why there has always been the greater need for extra support for a BD; be it a thicker iron, a cap iron, a lever cap etc; regardless of what possible extra benefits such upward curve on the secondary iron may have been found to have since. 

Huh? Huh? Etc..


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## Jacob (26 Jan 2012)

Vann":3yj0hgfw said:


> Jacob":3yj0hgfw said:
> 
> 
> > ...*BU blades are always heavy *and firmly held down so they don't need the extra hold-down effect of the cap iron.
> ...


Oh yes except for block planes! :roll: 
But IMHO they are hopeless for full width normal planing and are used for trim, small stuff etc. so don't count.
No doubt someone will say differently!


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## bugbear (26 Jan 2012)

In the context of a thread that wandered off into entirely hypothetical plane components, I see no reason to have assumed that block planes "don't count"

BugBear


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## bridger (26 Jan 2012)

two things here. bevel up planes like block planes can be supported by the frog a lot closer to the edge which lends them stiffness. they almost always are bedded at lower angles than bevel down planes which means that the body of the blade is closer to being in line with the cutting force.


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