mortise chisel shape data

Re: mortise chisel shape data

Warren in Lancaster, PA

I wonder if you are really seeing the factory grind. This chisel might be 150 years old, but it looks like either it was in plastic wrap or somebody really worked it over in the last year. Actually if you look at where the shaft meets the bolster, you can see that the guy that cleaned it up had trouble getting in the corners. This suggests abrasive action to remove rust or whatever.

Maybe someone was just very good with a belt sander.

Re: mortise chisel shape data

David Weaver

It's fine to believe that's the case for one or two or five and a hundred that don't show the same thing.

It starts to be a bit of a dream to cling to thinking that's always the case when more than half of the chisels look like that and the ones that have been re-rounded by hand are very obviously reground (They aren't nearly as neat as that, and the varying stone marks can be seen).

It's possible that some were refinished on a leather wheel at some point with abrasive loaded in it and re-sold by a tool vendor. Who knows.

What's not unusual is that there's no rust on the chisel - it's being resold. What is unusual is the fact that it's that old and at some point it didn't get much deeper rust pitting.

I chopped four more deep mortises this week with one of mine that hasn't been modified and the ability of these to bring the last parts of the cut to vertical at the end of a mortise and rotate is far beyond anything with a thinner cross section or a sharp top merger. In order to do that in one pass instead of four, you have to mallet the chisel part of the way into the cut, break the chip, then pull it up ever so slightly (which you can't do if the top of the profile has a hard defined line) and then lever.

It's incredibly fast. It can also be inaccurate if someone is careless, but it is fine if the person doing the malleting is not.

Re: mortise chisel shape data

Bill Tindall, E.Tn.

There are several kinds of marks from manufacturing that assure me that the shaft of this chisel from bolster to near the tip has not been altered since it was first made, except the face. For example there is a slight chamfer made by grinding the softens the edges of the bevel side. They go tip to to the bolster. The face has been been polished along most of its length.

But the shape is clearly what it is. Somebody obviously preferred it or they would have altered it. It sure as hell was not made this way to sell at a tool collectors meeting.

If this is not a superior shape for some kind of mortising how do you account that it is shaped this way? It seems an example of a statement I made before that was met with derision. Given the possible inaccuracy of reporting as well as the possibility that important variables are different, reading how some large shop (factory) did something XX years ago could be a poor guide for how to do it under different shop conditions.