I need to rip vertically a large number of Cherry boards and don’t own a bandsaw or can I afford one. So after some research, I determined that I could make a kerf plane and a frame saw which would allow me to accomplish the task. Of course that would mean lot’s of manually sawing later but that is ok, I need the exercise. The general principle is that the kerf plane makes a narrow cut or kerf in the wood at a set distance from the edge of the board. And when you make cut all of the way around you then create a groove for your handsaw to follow with idea that the blade will follow the path of least resistance.
My initial research came up with a kerf plane by Tom Fidgen of “The Unplugged Workshop” in Toronto. He has a video series on how to make his. A photo of the finished fixed fence version is below.
Beautiful plane, has the traditional western saw handle incorporated into the body and is a fixed distance and a fixed depth. In his book he shows how to make an adjustable fence version as well. But what is interesting is that there is another hand saw that effectively does the same thing but was designed for a different purpose, the Stair Saw.
Stair saws, as the name implies, were originally designed to cut dado joints for stairs, but they are useful for dado joints of all sizes. Below is a patent filed by Charles Lofdahl in 1925 and granted in 1926.
US Patent: 1,607,403
It is a simple wood block with the blade centered in the middle and and the craftsman would use some sort of fence to run the saw against initially to set the first cut into the wood. Some photos of stair saws are below:
An antique stair saw that has seen better days.
The one above was a commercial version from one the most famous hand saw makers of all times “Henry Disston & Sons”. They were based out of Philadelphia and hundreds of saw models with the rip and crosscut saws or panel saws as they are some known as the most well known.
And finally here is an example of a newly made stair saw by fellow modern day craftsman. The wheat grain pattern on the saw is reminiscent of the Disston saws. So to me the Stair Saw and Kerf saw are essentially cousins in the hand tool world.
Now my kerf saw is based more on the japanese model of hand planes, less decoration and basic function.
It’s a simple design, the main rectangular block is to hold the blade and is also the handle and made out of mesquite firewood. The blade sits against the block and an oak spacer sets the fence made out of Sapele at the distance needed. In the above picture the spacers are exaggerated to show more detail. The saw blade itself is specially made by Bad Axe Toolworks and is the one that Tom Fidgen used in his model. Below are some photos of the step by step build sorta. Kind of hard to remember to take photos when you are making something.
A block of Mesquite Firewood about to be sawn in half with the Disston D8 rip saw in the background.
The two pieces and below is the one I chose.
There is a fence is made of sapele and is connected to the main block by brass screws. I made two 20mm oak spacers for between the fence and the handplane. Essentially I cut a rabbet into the side of the mesquite block tall enough to hold the blade with enough depth showing for a decent cut into the wood.
The 3″ brass crews go through the block, the blade, spacers and into the fence. I capped them off with knurled brass nuts but I will be changing them out for brass wing nuts. I can’t seem to get the knurled nuts tight enough and the fence becomes loose with use which isn’t a desired benefit of using the tool.
So this is my first test using the kerf saw, so far so good.
And now the final result below:
Well the kerf saw worked fine other than the fence coming loose because of the knurled nuts I used to tighten. (I’m changing that). My sawing was severely hampered by my malfunctioning vise that kept slipping and letting the wood move when I was cutting it. Only cut my left hand 7 times trying to hold the wood while cutting. (Dummy). I then adjusted the spacing and cut three boards out of one.
Sorry for the fuzzy photo but being able to cut three boards out of one is a first for me and a terrific new capability in the shop. Not a bad little project, give it a try.