Mortise bit sharpening questions

[Selwyn]

Ok I've been trying to sharpen my collection of mortise chisels and bits. Been following youtube and have cone sharpened the chisel internall and taken off the burr.

On some the the chisel bits some of the don't seem to a have a point - just two spurs. And others have one point and one spur. I'm presuming the ones with one spur and one point are english pattern and the other is japanese?

I'm finding the one with two spurs is a bit useless - is it meant to have a point which has broken off or not?

What file do you use for sharpening the bit - some sort of needle file?

 

[Beau]

Always used a set like this http://www.amazon.co.uk/Cutting-Edge-Cl ... B00IEI2QV6 No way I paid that kind of money though.

 

[Selwyn]

Always used a set like this http://www.amazon.co.uk/Cutting-Edge-Cl ... B00IEI2QV6 No way I paid that kind of money though.

Thanks I'm using an axminster cone for £3 for that bit.

I still feel its not cutting well but I didn't polish the sides of the chisel, the bit seems to be making a hell of a noise too and I suspect the spurs on the bit aren't sharp enough.

 

[Phil Pascoe]

A needle file (or anything small enough, really) will do the bit. If it's making a hell of a noise you may have the bit set up too close to the chisel. You need a little more clearance than you'd think.

 

[Selwyn]

A needle file (or anything small enough, really) will do the bit. If it's making a hell of a noise you may have the bit set up to close to the chisel. You need a little more clearance than you'd think.

Ah ok thanks. Another question - can I use a metric bit in an imperial chisel or not?

On second thoughts a chainsaw file would probably do the bit

 

[Phil Pascoe]

If the bit were too large the chips would jam, if too small you have a job to plunge the chisel in - but within reason I don't suppose it would make too much difference. There's an easy way of finding out ...

 

[custard]

Ok I've been trying to sharpen my collection of mortise chisels and bits. Been following youtube and have cone sharpened the chisel internall and taken off the burr.

On some the the chisel bits some of the don't seem to a have a point - just two spurs. And others have one point and one spur. I'm presuming the ones with one spur and one point are english pattern and the other is japanese?

I'm finding the one with two spurs is a bit useless - is it meant to have a point which has broken off or not?

What file do you use for sharpening the bit - some sort of needle file?

It's the reverse, English pattern is two spurs and no point, Japanese pattern is one spur and a point. Actually the differences go quite a bit further. Japanese pattern generally has a different flute geometry that will clear the chips faster, plus a much more acute angle on the chisel, and the chisel width is deliberately relieved immediately behind the cutting edge to a much greater degree than English pattern. Maybe this reflects more softwood use, I don't know? You need a different cone for sharpening Japanese and English chisels even if they're the same size (or at least you do if you want to preserve the chisel angle).

I've spent forty years as a die hard English pattern user. But with the demise of Clico I've looked again at Japanese pattern chisels and I think my prejudices may have been overstated. I still prefer English pattern for really hard woods, say tougher Oak and Beech, and certainly for the exotics. But for Cherry, Brown Oak, and Walnut for example the top of the range Japanese chisels probably have the edge.

I sharpen the auger with a triangular saw file. The same rules apply for mortice chisels and augurs as most other tools, if you haven't raised (and subsequently removed) a burr then you haven't actually sharpened the tool.

Cheap mortice tooling, Japanese or English, is generally pretty nasty stuff.

If you're unhappy with the performance I'd suggest you're struggling with blunt tooling, cheap tooling, or the mortice machine isn't properly set up.

 

[Guggs]

Aim to get a nice small even burr on the chisel . It takes practice but it's well worth it .
Once the chisel has a small burr on the four outside faces DO NOT hone these off . Time and time again you see chisels honed up !
Wrong !
Leave the burr on as this helps with the cutting also over honing can cause the chisel to 'narrow' down at the working end this , in some extreme cases can lead to the chisel sticking in deep stock .
Also make sure the auger wings are slightly proud of the chisel body again this all adds up to a really effective and efficient morticing .

 

[custard]

I always hone the burr off!

On English pattern I also hone the four flats to a mirror polish precisely in order to prevent sticking. On Japanese pattern, with their more pronounced relief above the chisel's actual cutting edge, I just knock off the wire edge with a quick swipe on a very fine stone. I work on the basis that sharpening every other tool requires the wire edge to be removed, so why should mortice chisels be any different?

But hey, that's why the internet is a lousy substitute for face to face learning, if you get five replies then you'll have at least six different opinions, but of course none of them will carry any actual responsibility for helping you progress!

 

[Selwyn]

I always hone the burr off!

On English pattern I also hone the four flats to a mirror polish precisely in order to prevent sticking. On Japanese pattern, with their more pronounced relief above the chisel's actual cutting edge, I just knock off the wire edge with a quick swipe on a very fine stone. I work on the basis that sharpening every other tool requires the wire edge to be removed, so why should mortice chisels be any different?

But hey, that's why the internet is a lousy substitute for face to face learning, if you get five replies then you'll have at least six different opinions, but of course none of them will carry any actual responsibility for helping you progress!

Whilst I'm grateful for all the advice I agree that the internet can destroy the confidence when trying to get head around something new to me!