flattening chisel backs with lapping film

[bugbear]

So we've laid to rest the flattening myth pretty convincingly.

We've shown that flat chisels are needed for accurate straight cuts.

BugBear

 

[Phil Pascoe]

BB- you got the wrong word - it's now "co-planar" not "flat".

 

[Dangermouse]

So we've laid to rest the flattening myth pretty convincingly. This should save woodworkers millions of hours! Should there be an official announcement of some sort?
quote]

It would save woodworkers millions of hours too, if they all stopped typing hundreds of posts about flattening chisel backs and just got on with it. :shock: (hammer)

 

[marcus]

So we've laid to rest the flattening myth pretty convincingly.

At first I thought that arguing with Jacob was like taking candy from a baby. Then I realised it's not as interesting as that. It's like taking candy from a baby who's incapable of realising that the candy's gone.

 

[marcus]

And while I'm on the subject of childishness....

What is the point in discussing with someone who is repeatedly shown to be making factual errors, but every time this happens diverts attention by raising an unrelated point? Who seems unable to accept that different approaches and motivations exist to his own? Or who can have a long conversation that shows quite clearly that there are other points of view as valid as his own, but then waits a bit and comes banging back with exactly the same statements made at the beginning as if the entire conversation hasn't happened? Or who seems unaware that one point of dialogue is to expand and deepen ones viewpoint rather than endlessly repeating it? Or who either can't or won't come to the point where people say 'live and let live', and let things drop.

Obviously it's a waste of time and energy. I can't work out if he is trolling for fun or actually means what he says, but every time I engage I regret it. You just can't have a meaningful conversation with a person who seems to be inherently incapable of compromise and who needs to be right this badly.

 

[bugbear]

..I can't work out if he is trolling for fun or actually means what he says...

I've never been able to answer that one either. I think it's quite a lot of both.

BugBear

 

[Paul Chapman]

Obviously it's a waste of time and energy.

Which is why so many people don't bother posting on here any more.......

Cheers :wink:

Paul

 

[GazPal]

We've shown that flat chisels are needed for accurate straight cuts.

BugBear

How on earth they managed to build the Egyptian pyramids, Mayan temples, Parthenon and Harrison's wooden timepieces without perfectly flat chisels I'll never know. :roll:

Chisels have limitations when put to use and this gave rise to the development of the hand plane, abrasive papers, etc., etc.. Whilst the reach of a paring chisel is handy, the tool itself is not necessarily an accurate tool, as it's blade - by nature - is flexible and can distort during use. Especially so when it encounters grain travelling in contrary directions. This makes it necessary for one to constantly relax/increase downward pressure on the blade with one hand whilst the other steers via the handle. We don't introduce it's edge to the material and trust it will travel straight and true when driven forward primarily because it won't. Again, more emphasis needs to be placed upon tooling technique, because finite degrees of accuracy within a tool's manufacture are not the sole factors dictating accuracy in the cut. Shift focus on to chisels driven via maul or mallet and the pursuit of a perfectly straight blade becomes pointless as the steel shifts beneath each strike and wanders freely in the cut unless guided by hand and eye. Our senses play a much greater part in the ability to cut straight and true than seems accepted.

Books don't tend to teach this and a scientific approach toward chisel use tends to prove inappropriate unless every eventuality can be calculated with provision for formulae and converted to describe the physical reactions of materials, tools and tool user. But then we'd need to shift a proportion of focus away from crafting and on to calculus and translating scientific results into actions belonging in the realms of the machine driven world.

How long is a piece of string/How accurately ground should a blade be along it's length? It depends...... I mention this is because much depends upon cut dimension (Reach & breadth), blade flex and potential user error. Accurate tools are a real and genuine necessity, but - even with laser-like precision - more emphasis needs to be placed upon tooling practices than the tools themselves. Otherwise we become tool owners and not tool users and run the risk of losing sight of the skill sets developed over the ages for manipulating timber into various forms.

I tend to err on the side of accurate layout, sound technique and matching a tool to it's given task as being necessary for one to achieve accurate work. Straight or curved. Pinpoint accuracy in woodworking is perfectly possible without any need for engineering tolerances in the tools we use and this fact has been proven/borne out time and time again for millennia.

 

[DMF]

For what its worth i for one have loved these threads! As i'm right at the start of all this i've had nothing to add to the discussion so far but i would like to say that it's nice to find a place where there is a group of people who all clearly care about these subjects and i have to say overall i think the manner in which they have been discussed is a credit to this site.

I've been learning loads of you lot, of course we all have our own ways of doing things in life but it's down to me to choose my own way, this forum has provided people like me with the opportunity to hear from lots of different people with lots of different views, pretty handy really considering the many different scenarios i'm going to be coming across when i get going!

Basically it sounds like i need a few bashers (firmers as i now know) and a few tarty ones of some description :lol:

Anyway i'll go and hide again, thanks!

Dean

 

[marcus]

more emphasis needs to be placed upon tooling practices than the tools themselves.

The best craftspeople I have met, ie the ones producing the finest work have, without exception, cared a great deal about both. I think it has probably always been that way. I'm one hundred percent sure that the best and most skilled stone age wood carvers were the ones with the shiniest flints — and the best hand skills.

Also, how do you know that someone who posts about ways to make a chisel sharper isn't also making things? I'm sure there are a few people who do just sharpen tools and not making anything (which is their right if they enjoy it), but it's an unjustified assumption that because people are interested in tool sharpness they are not also producing work with those tools.

 

[bugbear]

We've shown that flat chisels are needed for accurate straight cuts.

BugBear

How on earth they managed to build the Egyptian pyramids, Mayan temples, Parthenon and Harrison's wooden timepieces without perfectly flat chisels I'll never know. :roll:

Chisels have limitations when put to use and this gave rise to the development of the hand plane, abrasive papers, etc., etc.. Whilst the reach of a paring chisel is handy, the tool itself is not necessarily an accurate tool, as it's blade - by nature - is flexible and can distort during use. Especially so when it encounters grain travelling in contrary directions. This makes it necessary for one to constantly relax/increase downward pressure on the blade with one hand whilst the other steers via the handle. We don't introduce it's edge to the material and trust it will travel straight and true when driven forward primarily because it won't. Again, more emphasis needs to be placed upon tooling technique, because finite degrees of accuracy within a tool's manufacture are not the sole factors dictating accuracy in the cut. Shift focus on to chisels driven via maul or mallet and the pursuit of a perfectly straight blade becomes pointless as the steel shifts beneath each strike and wanders freely in the cut unless guided by hand and eye. Our senses play a much greater part in the ability to cut straight and true than seems accepted.

Books don't tend to teach this and a scientific approach toward chisel use tends to prove inappropriate unless every eventuality can be calculated with provision for formulae and converted to describe the physical reactions of materials, tools and tool user. But then we'd need to shift a proportion of focus away from crafting and on to calculus and translating scientific results into actions belonging in the realms of the machine driven world.

How long is a piece of string/How accurately ground should a blade be along it's length? It depends...... I mention this is because much depends upon cut dimension (Reach & breadth), blade flex and potential user error. Accurate tools are a real and genuine necessity, but - even with laser-like precision - more emphasis needs to be placed upon tooling practices than the tools themselves. Otherwise we become tool owners and not tool users and run the risk of losing sight of the skill sets developed over the ages for manipulating timber into various forms.

I tend to err on the side of accurate layout, sound technique and matching a tool to it's given task as being necessary for one to achieve accurate work. Straight or curved. Pinpoint accuracy in woodworking is perfectly possible without any need for engineering tolerances in the tools we use and this fact has been proven/borne out time and time again for millennia.

Everything you say is true, but (I believe) addresses a broader question (and context) than the one I was positing, which was the specific act of paring (which does not require a long, patterning maker's paring chisel).

It is (I thought) fairly obvious that a flat backed chisel, taking a fine paring cut, will pretty much continue in a straight line for a short distance, which is what most joints involve. Conversely, a curved or back bevelled chisel will require a great deal more input and control from the operator for the same operation.

Flat does not have to mean polished, of course.

BugBear

 

[Jacob]

..I can't work out if he is trolling for fun or actually means what he says...

I've never been able to answer that one either. I think it's quite a lot of both.

BugBear

Of course I mean what I say. Do you think I am furtively flattening my chisels in secret?
There is a vast amount of silly misinformation doing the rounds which wastes a lot of time and resources. It's often very plausible on paper or on video and many of the perpetrators seem to acquire guru status, esp with novices. But in practice it's often worthless, and they should be ignored.
I came to this conclusion after getting more interested in hand tools over the last few years and doing a lot of fiddling about trial and error. Before that I even used to use a honing jig! Silly me! And I have been making wooden stuff all my life and earning a living from it, starting in 1969 selling wooden toys to Carnaby Street shops. Anybody remember "Gear" and next door "Kids in Gear"?

 

[marcus]

Conversely, a curved or back bevelled chisel will require a great deal more input and control from the operator for the same operation.

This has been my experience with tasks like trimming tenon cheeks. It's easier, quicker and pleasanter if the chisel is flat. I'm not talking engineering flat. But the point is if you like to keep your chisel backs flat for this reason, and you like the additional sharpness that a polished back brings, then the back needs to be flat enough so that when you rub it flat on the stone the mm or so behind the cutting edge is polished. Which sometimes takes a bit of work when the chisel is new, but in my experience repays you with increased efficiency and enjoyment thereafter. Which is why most of us who do it, do it.

And no I am not advocating engineering tolerances for chisels — just the work necessary to get the result indicated above.

 

[Phil Pascoe]

Right, that's that out of the way, then. I assume we should all flatten the soles of our planes? No!..........no!............don't go there!

 

[Phil Pascoe]

Yes, I meant flat not "co-planar".

 

[Jacob]

Nobody is saying that they shouldn't be flat. But what we are saying is that madge (our OP) is wasting her time - routine flattening of all new chisels is nonsense - most chisels are flat enough for all normal purposes and just need sharpening. That's all!
Not many people have taken much notice of the OP, except some suggestion that Blue spruce chisels shouldn't need flattening. :shock:
What would you say to madge?

 

[bugbear]

Right, that's that out of the way, then. I assume we should all flatten the soles of our planes? No!..........no!............don't go there!

Jacob argued long and loud against that, with his usual vitriol.

Later he sold a plane because the sole wasn't flat enough (although the fault was omittted from the eBay description) , and now advises "sagely" on flattening technique.

BugBear

 

[Jacob]

Talking nonsense and trolling again BB!
What would you say to madge (OP)?

 

[Peter Sefton]

We do have 80 micron (180 grit) lapping films - 100 is pretty coarse for such high quality chisels, the finer the abrasive the flatter it will be and the more imperfections it will highlight on tools.

I have never lapped Blue Spruce but would be reluctant to do so on very coarse abrasives as I would hope the chisels are made to finer tolerances than that. Lapping on glass plate does show up all manufacturing imperfections which you may not show up with other sharpening mediums.

The Op was how to flatten chisels with lapping films but it would be great if Dodge could sort out a tool sharpening day, we could get together and demonstrate some techniques that we use ourselves. I would love to see Jacobs rounded bevel I have heard so much about it! I did and do still demonstrate oil stones but have progressed to other sharpening methods personally, Jacob show what I am missing (don't tell me).
If I am on site or hacking out then the oil stones is fine and an old rounded chisel will do the job but for finer work I work to finer tolerances.

 

[GazPal]

Yes, I meant flat not "co-planar".

But of course :lol:

------------

Back to paring, the area necessary for trimming tenon cheeks and shoulders, etc., flattens during the honing process, as we remove sharpening burrs. The amount of blade flattened varies per user and would often depend on the width of his/her sharpening stones and the scale of work undertaken, but seldom a full blade length and shouldn't involve much initial prep work.

Conversely, a curved or back bevelled chisel will require a great deal more input and control from the operator for the same operation.

This has been my experience with tasks like trimming tenon cheeks. It's easier, quicker and pleasanter if the chisel is flat. I'm not talking engineering flat. But the point is if you like to keep your chisel backs flat for this reason, and you like the additional sharpness that a polished back brings, then the back needs to be flat enough so that when you rub it flat on the stone the mm or so behind the cutting edge is polished. Which sometimes takes a bit of work when the chisel is new, but in my experience repays you with increased efficiency and enjoyment thereafter. Which is why most of us who do it, do it.

And no I am not advocating engineering tolerances for chisels — just the work necessary to get the result indicated above.

I agree and have never disagreed, but there comes a point of diminishing returns where the work invested in polishing ceases to influence end results.

It's often much easier to grind an edge or flat face back mechanically than risk wearing out oil/diamond/water stones unnecessarily. The first few swipes on an oil stone typically lends feedback to the manner of work needed. The edge of a grinding wheel easily restores an off-kilter edge and the side of the grinding wheel is typically sufficiently sound to flatten chisel and plane iron faces to an easily refined level.

N.B. Just be sure to check grinding wheels are sound before use. If a grinding wheel is unsound you need to discard it without further use, as damaged wheels can disintegrate swiftly and violently when under load. Blood is torture to remove from timber and also rusts steel and iron like crazy if left laying around while you're at hospital getting stitches.