Marking knives are one of those multifarious paraphernalia that have not made it’s merry way to the distant shores of Namibia. Seeing that it is a fairly vital tool in a proper woodworking workshop, I had to make a plan.
First, I set off to find some reasonable steel for the project. I decided to use the blade of an old Bailey no.4 hand plane of my Dad that I am busy revitalizing. There are some Lie-Nielsen custom replacement blades on it’s way to me as we speak to replace this particular blade. Anyway, so the steel was sorted. Then I had a good ferret around for suitable off-cuts of wood for the handles.
Finally, I decided on some Tamboti (Spirostachys africana) and Witels (Playlophus trifoliatus). I only have two very small pieces of Tamboti that have probably traveled more than 2000 km over 15 odd years with my father and already 1800 km over 13 years with me. Maybe it is time to do something with it. The first two pictures below show the old plane blade on the Witels wood. The copper ring you spot is one of those the plumbers use to join copper pipes. Clearly I need to improvise and use what is available.
You will usually find these gargantuan Witels trees in the wettest parts of the forest.
In the next few pictures you can see the small piece of Tamboti. I deliberately chose to cut a blank that contains a bit of sapwood to show off the beautiful colour contrast. These blanks were so small that I had to improvise again in order to fit it on my antediluvian lathe. You can see the plywood wheel with a recessed area accepting the blank that is screwed to a bigger piece of hardwood. Yes it is fiddly to say the least.
Here you can see the turned Tamboti handle. The sapwood really adds some je ne sais quoi, don’t you think? You can also see the part of the blade allocated to this particular knife. The front part of the handle is turn to be a fraction bigger than the hole through the copper ring, but with absolute end slightly smaller to get it going when tapping it over with the blade in place. A take-home message from turning this blank, is to look for wood that has fairly straight gain throughout. The haphazard gain pattern on the front of this blank looks nice but does compromise it’s strength somewhat.
Below you can see the Witels blank being shaped on the lathe. This was the first time I have turned Witels and only the second time I have worked with it at all. In hindsight it is probably not the best wood for this application as it is very porous and softer than what I am used to if compare to Assegaai (my go-to wood for tool making). Nonetheless I do not think there are too many people with Tamboti and Witels marking knifes.
Unfortunately I did not take pictures of how I shaped the the blade or the internal design of how it was fitted to the handle. Therefore I made some crude Sketchup drawings to give you an idea.
You can clearly see the shape of the blade. It has a thin shaft that was inserted into the hole drilled down the middle of the handle. That part of the shaping was done by cutting it roughly to size with a grinder and finished off with hand files. The front of the blade however took ages as I did not want to overheat the steel and lose the temper. Therefore it was done slowly over hours with water stones and wet-and-dry sanding paper. Part of the blade was seated inside a slot cut into the front part of the handle, which clamped down on it when the copper ring was tapped over that section of wood. I also use epoxy to help fix the blade to the hilt (if you pardon the pun). It was inserted down the shaft’s hole, as well as inside the slot. Something that worked very well was the epoxy on the wood that came into contact with the inside of the copper ring reduced the friction significantly while tapping it over.
Here you can see the final product. The Tamboti knife has a fairly short blade for all the run-of-the-mill work. The Witels knife has a blade almost double the length of the first and also sports a slightly more Brobdingnagian handle.