Reply To: What 2 hand planes to start with.

#779770
Tom Wright
Participant

Thank you Sven-Olof,
Thank you for adding this relevant information!
Along these lines, I learned that chopping end-grain with a chisel has complexities around the type of wood.
I once chopped end-grain on a dried beam of Douglas Fir that I assumed would be easy on my chisel. Instead, to my alarm, the confident first chopping quickly folded said chisel edge in certain areas. Areas that I think corresponded to the harder portions of the growth rings – that were surrounded by spongier, softer wood. The chisel was fairly damaged in fact. This chisel was not a Japanese chisel with a very hard cutting edge smithed to a softer body. It was a generic Western-type chisel with consistently softer steel through the blade.

I learned that day that the homogeneity or lack thereof in wood may really affect a chisel’s capability while chopping end-grain. If a wood is hard or soft, but highly homogenous in density and resistance to the severing of its fibers, a chisel is more evenly “supported” by surrounding wood during the blow of a mallet. In other words the chisel meets with relatively even stresses along its cutting / severing edge.
Then take the highly un-homogeneous wood. And assume that the chisel meets the growth rings at a nearly parallel angle as in chopping down the end grain of a quartersawn board, with growth rings pointing upward toward the chisel. The chisel is struck, and the stresses upon the blade’s edge are concentrated where the wood’s harder strands lie. And the chisel is more prone to deformation of edge.

This description is still a simplification of what is happening. The bevel angle of the chisel and the chopping depth before relief-cutting also influence how a chisel fares when chopping like this. If heavy chopping is done all at once with no relief to the chisel bevel, I believe that the forces of pressed wood against the bevel “pile up” or pressurize and “try” to deform the chisel edge. And if the harder growth rings pass down the chopping face at any angle, think about how this would further press for deformation of an edge with several heavy blows to a chisel into this wood. This all is the best explanation I have for why a chisel unexpectedly failed in what I thought was soft wood. Perhaps there were other variables and unfortunately I don’t have a fully scientific compilation and report to offer. I hope this may serve as material for thought.

One may suspect that Japanese chisels evolved with this type of material in mind. Material that may be termed softwood but that has exceedingly hard growth rings alongside very soft growth rings. A Japanese chisel is build with the goal of delivering a hard slicing edge on a tool that is not liable to crack from brittleness. Perhaps also, this is the best goal for dealing with any wood. Or weapon such as a sword.

Thanks again for the photo-illustrated discussion of climate and growth rings as related to tool design. It certainly got me thinking.
Sincerely,
Tom
Maryland