Talking further upon the recent thread about bench chisels being just as good (or often claimed to be better for mortises), I've cut 16 mortises in door stiles the last couple of weeks. If it weren't for actually making all of the doors and fitting miters, I would've just cut them all in one day (because it's fun).
I'm testing a modified sharpening method (shallower angle, but buffer at the edge of the chisel, so I wanted to try it on a bench chisel and cut 12 of the mortises with a bench chisel (not interested in making a tall cross section mortise chisel have a really long thin primary bevel). The bench chisel held up well, and it's a low quality chisel, so the sharpening method works well, but..
...I cut the mortises for the last door yesterday (1/4" wide, 1 3/4" long and 1 1/2 inches or so deep) with an unusual socket mortise chisel, and the time spent on those was 3 minutes per (thanks to the magic of stopwatches on cell phones, I could figure that out easily). I didn't time the bench chisel mortises, but I fought with them and had to go to greater length to get chips out, they were probably closer to 5 minutes, but much less controlled.
With a mortise chisel, if you ride the bevel into the cut, the chisel cross section makes it so that at the bottom of the cut, you push the chisel forward, and the chip and some other stuff anywhere near it is cleaned from the bottom of the cut and you can just flip it out of the mortise.
The sellers video that everyone refers to shows this, but it's an easy thing to do when wood is attached only on one side. In cherry with a bench chisel (and a mortise attached at both sides), it doesn't happen so well.
With the mortise chisel, the mortise is cut faster (see the picture - the chisel in the back here is the one I'm talking about - these mortises are a bit small for a giant pigsticker, though they're long enough), the alignment is better and the chip clearing is far better - you can just hammer until you're done and then turn over whatever is being mortised when done.
https://i.imgur.com/4OW6iax.jpg
What's the point? If you're relatively new, don't rely on gimmick internet videos to make decisions. If bench chisels were better for cutting mortises, nobody would've been able to sell mortise chisels when there was little spare cash. you can test this kind of thing on your own relatively cheaply (just buy a used chisel like I've got here. The dealer for this chisel did make me pay a princely sum - something like $19, but it's a nice size for cabinet mortises in the size that I use a lot (1/4")
There is a type that also works better than anything made now, but you won't easily find them - I believe they're an artifact of hand making of tools - mortise chisels that taper slightly along their length. Not only do they have a tall cross section, but the bits of the chisel up from the edge don't get stuck in the cut easily, and the tool rotates and cuts more easily. The slight taper makes no real difference in cutting the mortise (in terms of accuracy). Why suspect it's an artifact of hand making? If you're forging a chisel by hand and have two targets to aim at - perfectly parallel or slightly biased to taper in width, the latter is far easier to make without causing a toxic problem (a chisel with spots wider than the cutting edge is toxic in a mortise, even if the error in making is small - I had a japanese chisel that wasn't quite right - it was like that, and it would stick so hard in normal mortise cutting that it broke).
I'm testing a modified sharpening method (shallower angle, but buffer at the edge of the chisel, so I wanted to try it on a bench chisel and cut 12 of the mortises with a bench chisel (not interested in making a tall cross section mortise chisel have a really long thin primary bevel). The bench chisel held up well, and it's a low quality chisel, so the sharpening method works well, but..
...I cut the mortises for the last door yesterday (1/4" wide, 1 3/4" long and 1 1/2 inches or so deep) with an unusual socket mortise chisel, and the time spent on those was 3 minutes per (thanks to the magic of stopwatches on cell phones, I could figure that out easily). I didn't time the bench chisel mortises, but I fought with them and had to go to greater length to get chips out, they were probably closer to 5 minutes, but much less controlled.
With a mortise chisel, if you ride the bevel into the cut, the chisel cross section makes it so that at the bottom of the cut, you push the chisel forward, and the chip and some other stuff anywhere near it is cleaned from the bottom of the cut and you can just flip it out of the mortise.
The sellers video that everyone refers to shows this, but it's an easy thing to do when wood is attached only on one side. In cherry with a bench chisel (and a mortise attached at both sides), it doesn't happen so well.
With the mortise chisel, the mortise is cut faster (see the picture - the chisel in the back here is the one I'm talking about - these mortises are a bit small for a giant pigsticker, though they're long enough), the alignment is better and the chip clearing is far better - you can just hammer until you're done and then turn over whatever is being mortised when done.
https://i.imgur.com/4OW6iax.jpg
What's the point? If you're relatively new, don't rely on gimmick internet videos to make decisions. If bench chisels were better for cutting mortises, nobody would've been able to sell mortise chisels when there was little spare cash. you can test this kind of thing on your own relatively cheaply (just buy a used chisel like I've got here. The dealer for this chisel did make me pay a princely sum - something like $19, but it's a nice size for cabinet mortises in the size that I use a lot (1/4")
There is a type that also works better than anything made now, but you won't easily find them - I believe they're an artifact of hand making of tools - mortise chisels that taper slightly along their length. Not only do they have a tall cross section, but the bits of the chisel up from the edge don't get stuck in the cut easily, and the tool rotates and cuts more easily. The slight taper makes no real difference in cutting the mortise (in terms of accuracy). Why suspect it's an artifact of hand making? If you're forging a chisel by hand and have two targets to aim at - perfectly parallel or slightly biased to taper in width, the latter is far easier to make without causing a toxic problem (a chisel with spots wider than the cutting edge is toxic in a mortise, even if the error in making is small - I had a japanese chisel that wasn't quite right - it was like that, and it would stick so hard in normal mortise cutting that it broke).
