Mortise chisel angles.

[garywayne]

I picked up a mortise chisel at the car boot sale.

Do I sharpen it with the same angles as other chisels, or, do they have an angle all there own?

 

[Philly]

Gary
Normally you grind them at a higher bevel angle-try 30 degrees or higher.
Hope this helps
Philly

 

[garywayne]

Thanks Philly.

That is a big help.

I didn't want to go by the angle already on the chisel, because you don't know if who had it new what they where up to.

Also, I have never seen anything regarding the grinding angle of mortise chisels.

Thanks again.

 

[Anonymous]

You must enter a message when posting

 

[Joel Moskowitz]

THe historical standard on Ehglish oval bolstered mortice chisels is to grind the primary bevel at 20 degrees - this gives you penetration. Then put a small secondary bevel at 35 or so degrees. This gives you strength.

A single bevel at either will either not have the penetration or be too weak.

TYpcially the primary bevel was hollow ground on very large diameter wheels - but I have done it on regular 6" wheels. it all works but of course without the secondary bevel the chisel will bend or snap.

- I should mention that sash mortise chisels - which are considerable lighter in duty are mostly sharpened with a single bevel at about 35 degrees. But being sash mortise chisels they originally were designed for chopping mortises in window sashes -(shallow and softwood) - the the penetration angle isn't needed.

 

[Philly]

Joel
Welcome to the Forum!
Philly

 

[Alf]

Welcome, Joel. Good to see you here.

Cheers, Alf

 

[Anonymous]

You must enter a message when posting

 

[garywayne]

Thank you people, for your response.

Joel, (welcome to the forum), and Jacob, I think that I will give both of your ways a try, and see which one feels right for me, and go from there.

Thank you all again for your input.

 

[bugbear]

A rounded bevel all the way from shaft to edge is discussed in reasoned detail in Leonard Lee's book (IIRC)

BugBear

 

[Joel Moskowitz]

I was taught to hone at 30 deg (on an oil stone) ......
I always assumed "sash" mortice chisel meant a 1/2inch chisel, this being the most common size of a sash mortice and hence the one most used mortice chisel in general. . I wonder if they were termed "sash" chisels and intended for mortices in glazing bars, where a heavy firmer chisel is better for the job - the OBM being too thick for the hole.

cheers
Jacob

I think 30 degrees is way to high a primary bevel - but many people do use the rounding motion you describe ona much lower primary bevel. Sash Mortice chisels were specfically designed for shallower mortices in windows and have usually a single bevel and parellel sides. THe window making market was huge and much bigger than the cabinetmaking market

 

[Anonymous]

You must enter a message when posting

 

[Joel Moskowitz]

This would be the answer to the question of why tool makers make heavyish firmer chisels and call them "mortice" chisels; they are actually "sash" mortice chisels designed for the smaller mortices i.e. not always shallower, but smaller cross- section. Just an idea.

cheers
Jacob

It's not the tool makers who mis-name the chisels. As far as I know every maker of registered chisels calls them just that. Sash Mortise chisels look different. It's the tool retailers some of them mis-label registered chisels as "registered mortise chisels" so they have a cheaper lighter duty thingie that people can sort of use for mortising. But it' s a recent phenomena - you don't see it in pre-1970 or 80 catalogs.

Sorby I tihnk is the only current maker of real sash mortise chisels. They also make registered chisels, and heavy duty sash mortise chisels. They got the names all right in their catalog. It's some retailers who cause the confusion. Heavy duty sash mortise chisels are used for regular mortising but really come from the European tradition, not the English tradition which use Oval Bolster chisels for the purpose.

 

[Anonymous]

You must enter a message when posting

 

[JesseM]

Sorby I tihnk is the only current maker of real sash mortise chisels. They also make registered chisels, and heavy duty sash mortise chisels. They got the names all right in their catalog. It's some retailers who cause the confusion. Heavy duty sash mortise chisels are used for regular mortising but really come from the European tradition, not the English tradition which use Oval Bolster chisels for the purpose.

So I have a set of Sorby mortise chisels with the boxwood handles. I looked at the website I ordered them from a long time ago, and they still have them, but they are not labeled registered or sash. Are these the heavy duty sash mortise chisels?

 

[Joel Moskowitz]

Boxwood handles means that they are probably the sash mortise chisels.

the Sorby heavy duty mortise and their registered chisels have ash handles.

 

[Frank D.]

In France mortise chisels are usually ferruled. Bolstered chisels are typically English. Here's a typical French mortise chisel, quite like German pattern chisels:

 

[JesseM]

The Sorby's don't have ferrules which would make think they are not heavy duty, but the LNs don't have them either. Would the LNs be considered sash mortise chisels?

 

[Anonymous]

You must enter a message when posting

 

[Scrit]

The ones I saw in a market in Vaison la Romaine were most definitely the ordinary OB or pig sticker pattern. Of course I don't know how they got there - could have been abandoned by a wandering Brit joiner but they sort of looked local.

The Sheffield firms were early off the mark in the export market (Mathiesons, for example, was very active in South America of all places according to some of their catalogues), so they might have been Sheffield-made, or local copies of Sheffield-style tools. The "English" pattern hand saw, for example, has become pervasive in many parts of the world (or at least Europe), after all, and many European firms copied later American designs such as the Stanley Bailey plane. Or was it perhaps "war booty" from the 1940s?

Scrit