Swan-Necked Chisels - how useful?

[Andy Kev.]

Swan-necked chisels (fourth item down on the link) https://www.classichandtools.com/acatal ... isels.html are designed for tidying up the bottoms of mortices. The bottoms of my mortices tend to end up a bit ragged which has never bothered me too much as I think that flat and square sides should surely be of more importance. Given that swan-necks are meant to be levered and not struck, do they also help sort out the sides? More fundamantally, are they worth the money? I'd be happy to get one if it would improve the chances of producing more consistently good mortices and by "good" I mean mortices which require less fiddling about with to get a good fit for the tenon.

Any views?

 

[Rorschach]

I am guessing they are really only useful (and needed) on very shallow mortices.

 

[AndyT]

They are also called lock mortice chisels, which I think is a better name, as it identifies the one special case where they are useful.
If you look at Victorian doors you'll often see a broad lock rail where a round knob is fitted to a mortice lock, set well back from the edge, so your hand doesn't scrape on the doorstop. This backset can be about six inches or more.

So, to fit the lock, you need to cut a mortice about 5/16" wide, 4" long and 6" deep. At those proportions, the hole is too deep to make a cut along the bottom with an ordinary chisel.

Does it matter? I expect the majority of doors have ragged bottomed mortices mostly bored out with an auger bit. As long as you don't destroy the integrity of the joint, it really doesn't make a difference.

On modern work, the lock or latch will probably only need a simple drilled hole.

When it comes to smaller sizes of blind mortices in furniture work, I don't see a need either. Especially if the mortices are cut with a router or a Domino!

 

[Argus]

Interesting question...............

As Andy said, old doors had different dimensions to modern ones to accomodate the deeper locks of the period.

These chisels are still plentiful on the second-hand market and I bought a few about 20 years ago when I was doing a lot of deep mortises (not locks) in frames and they definitely did a good (and quicker) job of hacking out flat bottoms that were too deep for a power router to reach.
I don't do that sort of stuff any more and they've been in a drawer for years.
They need an entirely different approach to sharpening.

I believe that the Japanese have a tool for raking the bases of mortises that consists of a cutting edge at right angles to the deep shank of the chisel...... I have picture somewhere in a book. Different shaped tool - same application.

 

[Racers]

Interesting question...............



I believe that the Japanese have a tool for raking the bases of mortises that consists of a cutting edge at right angles to the deep shank of the chisel...... I have picture somewhere in a book. Different shaped tool - same application.

Bottom cleaning chisels if I remember correctly :shock:

Pete

 

[Doug71]

Bought one about 15 years ago and have never used it.

Doug

 

[Andy Kev.]

Interesting replies, especially about Victorian doors.

Do they have no effect on the side walls of the mortices then? In my opinion, they are more important to get right i.e. flat and square, than the bottom.

 

[custard]

They are also called lock mortice chisels, which I think is a better name, as it identifies the one special case where they are useful.
If you look at Victorian doors you'll often see a broad lock rail where a round knob is fitted to a mortice lock, set well back from the edge, so your hand doesn't scrape on the doorstop. This backset can be about six inches or more.

So, to fit the lock, you need to cut a mortice about 5/16" wide, 4" long and 6" deep. At those proportions, the hole is too deep to make a cut along the bottom with an ordinary chisel.

I didn't appreciate doors had mortices that deep, you'd struggle to cut those with the Sedgewick or Multico machines that you see in most small furniture workshops.

I always think of a "lock mortice chisel" as something different to a "swan neck chisel", in my mind it's a much smaller tool with a very specific job. Say you're fitting a lock on a drawer or on the fall front of a bureau. You can conveniently cut the larger mortice for the lock plate while you're still at the component stage, but you often have to adjust or even cut the mortice for the lock's bolt when the piece is finally assembled and glued up. Which means you need a tiny, handy little tool that'll get you into confined spaces. Maybe I'm calling it by the wrong name but that's the tool I think of as a "lock mortice chisel".

 

[AndyT]

Tool naming is never hard and fast. Salaman's dictionary calls the smaller, useful tool with the right angle bend a drawer lock chisel, or bolt chisel, or bolting iron, or lock bolt chisel.

And afaik, the swan necked chisel would only be used to clear out the bottom of a mortice previously cut with an ordinary chisel, or bored and pared.

Practically speaking, it is only the sides that matter, where the glue goes.

I do have a swan necked chisel and actually used it quite recently when I was upgrading a lock and needed to slightly deepen the hole. I'm sure I could have managed without, but there was precious little wood left by the time I had finished.