Making a Long-Blade Marking Knife

A couple of years ago while working on a chair, I found myself needing to lay out the position of the seat slats on the centre rail, which was basically a cross-lap joint. Normally, I’d use my marking knife for this operation, but due to the thickness of the components, my marking knife wasn’t able to reach.

So I grabbed an old chisel and quickly ground a spear point on the end to make my marks, then proceeded to complete the project.

Recently, Canadian Woodworking & Home Improvement hosted a hand tool build-off on their forum called Building Together: Hand Tools. I decided to make a long-bladed marking knife to complement my two short marking knives (shown on left of photo).

I think that at some point, somebody used the chisel with a steel hammer without a handle in the socket, so the inside taper had a lip. Since I wanted a handle for the marking knife, I started by filing the taper smooth.

I lapped the back on my 120-grit diamond stone, which was my coarsest.

I applied blue layout fluid to the back of the knife and used my regular woodworking tools to lay out the shape of the knife point.

With my bench grinder’s tool rest at 90 degrees, I ground the profile of the knife. Then, I tilted the tool rest and ground the bevels.

I selected a piece of dogwood with interesting grain and mounted it on the lathe.

I turned a taper on the end, and test-fit it frequently with the knife socket.  By rotating the handle in the socket, I was able to see where it was rubbing.  I removed those parts and kept checking the fit until the parts mated well.

I used an existing handle for shaping inspiration.

I shaped the handle and sanded it up to 180-grit on the lathe. At this point, I used a hand saw to cut off the handle and hand-sanded the end.

I applied a coat of oil to bring out the grain.

To complete the knife, I removed tarnish from the blade with a Rust Eraser, lapped the back of the blade to 600-grit, and ground the bevels flat (mostly for aesthetic reasons).  I finished sharpening the knife with a leather strop charged with honing compound.

Links:

• Building Together: Hand Tools