flattening chisel backs with lapping film

[János]

Hello,

Dear Jacob, for an example of a paring guide/saddle template take a look at this:
http://wangebote.de/251056114995/gehrun ... Flade.html

This is the type of tool BB has mentioned, I guess.

Have a nice day,

János

 

[bugbear]

Hello,

Dear Jacob, for an example of a paring guide/saddle template take a look at this:
http://wangebote.de/251056114995/gehrun ... Flade.html

This is the type of tool BB has mentioned, I guess.

Fancy!

Here's the traditional (and simple) form:

http://www.finewoodworking.com/workshop ... iters.aspx

Even the Japanese use them:

They crop up in old toolboxes rather commonly, being useful and easy to make.

BugBear

 

[Jacob]

Yes OK. A "normal" flat chisel would do. Any one out of my box. No special flattening required!

 

[riclepp]

Hello,

Dear Jacob, for an example of a paring guide/saddle template take a look at this:
http://wangebote.de/251056114995/gehrun ... Flade.html

This is the type of tool BB has mentioned, I guess.

Fancy!

Here's the traditional (and simple) form:

http://www.finewoodworking.com/workshop ... iters.aspx

Even the Japanese use them:

They crop up in old toolboxes rather commonly, being useful and easy to make.

BugBear

I got my late fathers one of these made out of mahogany

 

[GazPal]

Hello,

Dear Jacob, for an example of a paring guide/saddle template take a look at this:
http://wangebote.de/251056114995/gehrun ... Flade.html

This is the type of tool BB has mentioned, I guess.

Fancy!

Here's the traditional (and simple) form:

http://www.finewoodworking.com/workshop ... iters.aspx

Even the Japanese use them:

They crop up in old toolboxes rather commonly, being useful and easy to make.

BugBear

Perhaps from your standpoint, but they're not too uncommon in newer toolboxes either and I have one among my kit that sees use fairly regularly. My son also uses a mitre saddle/template. It's a simple enough paring guide and there's no need for higher than necessary levels of flat or polish in chisel blades when dealing with average sized work pieces.

Much the same can be said when considering the use of paring chisels in most context, as full blade length seldom becomes involved in a straight paring cut - unless patternmaking - or where accuracy is better served via the use of a handplane.

Surely it says a lot of the method or technique if flattening any surface takes longer than realistically practicable. Anything beyond five minutes spent on flattening a single chisel/plane blade is IMHO beyond reason and other methods should be sought and used before moving on to stones as a means of finishing the resulting surface.

 

[bugbear]

Hello,

Dear Jacob, for an example of a paring guide/saddle template take a look at this:
http://wangebote.de/251056114995/gehrun ... Flade.html

This is the type of tool BB has mentioned, I guess.

Fancy!

Here's the traditional (and simple) form:

http://www.finewoodworking.com/workshop ... iters.aspx

Even the Japanese use them:

They crop up in old toolboxes rather commonly, being useful and easy to make.

BugBear

Perhaps from your standpoint, but they're not too uncommon in newer toolboxes either and I have one among my kit that sees use fairly regularly. My son also uses a mitre saddle/template. It's a simple enough paring guide and there's no need for higher than necessary levels of flat or polish in chisel blades when dealing with average sized work pieces.

Good lord, yes. The only thing to avoid is a back bevel, which would make the chisel cut climb away from the desired line.

BugBear

 

[János]

Hello,

To call the back/front (the name depends on your perspective, so to speak) side of a chisel or plane blade flat is a misnomer, as it should be plane, and not flat. The back/front sides of Japanese cutting tools are hollow, not flat, but plane. You understand what I mean, don't you?
The paring chisels are used differently, than carving tools. A single bevel and a plane face/back is a necessity, otherwise you will be forced to use the tool like a carving chisel, and that is not the most efficient way of doing paring cuts. The paring chisel "jigs itself", thus requires much less effort to control the cut, a carver uses his hands and muscles to control and "jig up" the tool, to accomplish the cuts, as the tool - resting on the small surface of the bevel - is unstable, and prone to catch, run over, or dig in.

Have a nice day,

János

 

[Jacob]

Hello,

To call the back/front (the name depends on your perspective, so to speak) side of a chisel or plane blade flat is a misnomer, as it should be plane, and not flat. The back/front sides of Japanese cutting tools are hollow, not flat, but plane. You understand what I mean, don't you?

Yes. By "plane" you mean "co-planar".
I (and many others) call the flat co-planar side the face. Easy to remember and logical; flat = face, bevel = back

 

[Jacob]

......The paring chisel "jigs itself", thus requires much less effort to control the cut,

Yes in theory in ideal circumstances. If you float a paring chisel face down over a flat surface it will neatly trim off any bumps it encounters.* But surfaces are rarely like that (mostly flat with isolated little bumps) and in reality paring becomes just another mode of carving

a carver uses his hands and muscles to control and "jig up" the tool, to accomplish the cuts, as the tool - resting on the small surface of the bevel - is unstable, and prone to catch, run over, or dig in.

Have a nice day,

János

*A paring chisel will also dig in if it hits a big enough bump!

 

[Phil Pascoe]

Jacob - Co planar with what? Surely there is nothing on a chisel that is co planar with anything else?

 

[János]

Hello,

Dear Jacob, thank you for your help.
In my country and my mother tongue the naming is not as simple. In a cutting blade we call that side the "face" which will face the direction of cut in actual use. This convention helps in the discussion of cutting geometry. Yes, it is centered on machine tools, and does not account for single bevel chisels... And we call a bevel an "edgeband". :shock:

Have a nice day, :wink:

János

 

[bugbear]

Yes in theory in ideal circumstances. If you float a paring chisel face down over a flat surface it will neatly trim off any bumps it encounters.* But surfaces are rarely like that (mostly flat with isolated little bumps) and in reality paring becomes just another mode of carving

When doing final paring of a dovetail, the chisel edge is simply placed in the gauge line, the chisel (blade) set perpendicular to the workpiece, and the chisel pushed forward on its axis, remaining perpendicular to the workpiece.

Any chisel that needs to be held up at some angle to compensate for a back bevel would be a right pain.

Not sure who mentioned flat surfaces with little bumps.

BugBear

 

[Jacob]

Yes in theory in ideal circumstances. If you float a paring chisel face down over a flat surface it will neatly trim off any bumps it encounters.* But surfaces are rarely like that (mostly flat with isolated little bumps) and in reality paring becomes just another mode of carving

When doing final paring of a dovetail, the chisel edge is simply placed in the gauge line, the chisel (blade) set perpendicular to the workpiece, and the chisel pushed forward on its axis, remaining perpendicular to the workpiece.

Usually tilted in to undercut very slightly

Any chisel that needs to be held up at some angle to compensate for a back bevel would be a right pain.

I wouldn't recommend it particularly but I'm certain that if all you had were chisels with double bevels would get used to them in no time. Given a flat faced chisel you'd probably want to add another bevel immediately!

 

[Jacob]

Jacob - Co planar with what? Surely there is nothing on a chisel that is co planar with anything else?

:shock:
I suppose the edge itself and all the other extremities of the flat face should be roughly co-planar.

 

[bugbear]

Yes in theory in ideal circumstances. If you float a paring chisel face down over a flat surface it will neatly trim off any bumps it encounters.* But surfaces are rarely like that (mostly flat with isolated little bumps) and in reality paring becomes just another mode of carving

When doing final paring of a dovetail, the chisel edge is simply placed in the gauge line, the chisel (blade) set perpendicular to the workpiece, and the chisel pushed forward on its axis, remaining perpendicular to the workpiece.

Usually tilted in to undercut very slightly

Any chisel that needs to be held up at some angle to compensate for a back bevel would be a right pain.

I wouldn't recommend it particularly but I'm certain that if all you had were chisels with double bevels would get used to them in no time. Given a flat faced chisel you'd probably want to add another bevel immediately!

Perhaps, but it sounds doubtful. A straight cut with a flat chisel is simplest and best.

BugBear

 

[Jacob]

....
When doing final paring of a dovetail, the chisel edge is simply placed in the gauge line, the chisel (blade) set perpendicular to the workpiece, and the chisel pushed forward on its axis, remaining perpendicular to the workpiece.

Usually tilted in to undercut very slightly

Any chisel that needs to be held up at some angle to compensate for a back bevel would be a right pain.

I wouldn't recommend it particularly but I'm certain that if all you had were chisels with double bevels would get used to them in no time. Given a flat faced chisel you'd probably want to add another bevel immediately!

Perhaps, but it sounds doubtful. A straight cut with a flat chisel is simplest and best.

BugBear

If you pull apart old furniture with hand made DTs you will find that they are nearly always undercut slightly, from both sides, making a very shallow 'valley' in the shoulder of the pin hole. This is because it's easier, quicker, and ensures a tight fit at the visible join.

 

[Phil Pascoe]

Jacob - Co planar with what? Surely there is nothing on a chisel that is co planar with anything else?

:shock:
I suppose the edge itself and all the other extremities of the flat face should be roughly co-planar.

Flat, in other words?

 

[GazPal]

Hello,

To call the back/front (the name depends on your perspective, so to speak) side of a chisel or plane blade flat is a misnomer, as it should be plane, and not flat. The back/front sides of Japanese cutting tools are hollow, not flat, but plane. You understand what I mean, don't you?
The paring chisels are used differently, than carving tools. A single bevel and a plane face/back is a necessity, otherwise you will be forced to use the tool like a carving chisel, and that is not the most efficient way of doing paring cuts. The paring chisel "jigs itself", thus requires much less effort to control the cut, a carver uses his hands and muscles to control and "jig up" the tool, to accomplish the cuts, as the tool - resting on the small surface of the bevel - is unstable, and prone to catch, run over, or dig in.

Have a nice day,

János

I think the word you're searching for is "plain" and yes, the plain side is normally the unmodified flat or face, whilst the back is typically the bevelled side of the blade. Double edged chisels typically consist edge and blade, with neither side referred to as back or front.

When doing final paring of a dovetail, the chisel edge is simply placed in the gauge line, the chisel (blade) set perpendicular to the workpiece, and the chisel pushed forward on its axis, remaining perpendicular to the workpiece.

Any chisel that needs to be held up at some angle to compensate for a back bevel would be a right pain.

Not sure who mentioned flat surfaces with little bumps.

BugBear

Temporarily skipping across to the topic of masonry may help provide a few clues regarding chisel use, as they typically use double bevelled chisels for most of their cutting and dressing work, with the only single bevelled chisels in their arsenal consisting pitching tools and a select few carving chisels. As with carpentry, chisel work is generally thought of as a preliminary step toward final finishing (As well as a means of rapid stock removal). Yes, it is highly desirable for one to obtain surfaces as close as possible to the next level of tooling or desired finishing method, but IMHO more positive feedback can be gained via skill acquisition and tool manipulation than the pursuit of perfect flat.

Returning to carpentry and chisel use, paring differs to bulk removal (Such as dovetailing) as it generally involves surface reduction toward a finish level via the careful removal of minimal stock. Even a double bevelled chisel can be used to trim back to the line when prepping dovetails, because the norm is to slightly undercut the end grain face - at the line - in order to achieve final fit. Yes, we pare back to the line, but the amount of material removal involved is/should be minimal and paring to lines can be carried out using a single or double bevelled chisel without any need to hold the blade perpendicular to the adjacent work surface.

 

[GazPal]

Jacob - Co planar with what? Surely there is nothing on a chisel that is co planar with anything else?

:shock:
I suppose the edge itself and all the other extremities of the flat face should be roughly co-planar.

Flat, in other words?

Yes, flat/co-planar when all four corners and the intermediate surface rest at the same plain. :wink:

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

Past and present practices have proven chisels do not need perfectly flat face behind the cutting edge in order for one to pare straight and true in most instances. Typically because paring tends not to be a final step in the finishing process.

 

[Jacob]

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?
Polishing is another thing. IMHO the benefit of stropping (or buffing on a wheel etc) the bevel and a bit of the face reduces friction and improves the cut. Not something I'd do every time but a quick strop is good. NB Just 20 seconds or so, not hours of obsessive fiddling with graded diamond dust, plate glass, sundry gadgets or other madness!