Flush Cut Saw

Flush cut saw

I have a list of tools that I want, but don’t need; basically things I’d use occasionally, but not enough to justify buying them. From there I just pay more attention when I’m at flea markets and thrift stores, or eventually get to a point where I’ve “needed” it enough to justify buying a new one. A flush cut saw is on the list, but so is a double-edged Japanese saw, so buying a new flush cut saw is pretty much off the table for me.

Design Process

Growing up poor, I learned a lot about how to fix things and use what I already had to make new things. Last time I found myself needing a flush cut saw I looked around and grabbed a spare hacksaw blade – it worked great! Suddenly I had a flush cut saw and a very simple need: protect my hand from the blade by making a handle.

Handle Selection

I had a nice-looking piece of wood that was handle-sized, and there was a neat little bump at one end that would keep my hand from sliding off, so now I had a blade and a handle: I needed a way to attach them.

Borrowing from Knife-Making

I make knives: typically it involves inserting a blade into a handle and attaching it with metal pins and glue. Hacksaw blades have holes in both ends, and that’s what made the design for me: I realized I could hide half of the blade in the handle and bolt it from the bottom, letting me use each blade twice. I made a kerf down the handle, drilled a hole for the bolt, and gave it a “dry” assembly: all good!

Functional Aesthetics

The one thing left was a non-temporary way to hold the blade in the kerf. A hose clamp worked, but really distracted from the look and didn’t “feel” right. It also needed a shim to cover the ~2mm of space in the kerf. The wood is fallen forest wood, the bottom bolt is a bit big, the blade was 19c: it was developing into something very charming and functional, and a hunk of steel at the end wasn’t the right design decision. My design need had changed from the functional “protect my hand” to the aesthetic “finish the theme with elegance,” and it let me switch from “use what I have” to “use the right thing.”

With metal and glue out of the picture, tape not even an option, I grabbed some twine. It would fill the kerf and create the pressure needed to keep the blade in place, I could easily remove it, and it felt “right.” As a bonus it doubled as grip. I thought about how I needed to knot things and made a video, changing my mind on how to string it up after I hit the record button.

It works a lot better than expected so I couldn’t be happier. I think it looks great and fits in with tools I’ve made, and the twine’s added grip makes it feel really good in my hand. I finished up the project I was working on and added it to my tool collections – flush cut saw was now off the list!

The Aftermath

I used it quite often over the next few days – the flexibility of the blade was perfect for something I was working on so I used it more as a flexible saw than a flush cut.

I didn’t design a flexible saw. It broke.

Broken saw

Redesigning and Moving On

The blade breaking wasn’t surprising. Looking at where it broke, it’s pretty obvious it was my fault for making it flex so much. Having a flexible saw was unexpectedly handy, so I think flush cut is going back on the list. I’ll be getting a stronger blade and rounding the area where it inserts into the handle to accommodate movement.

The value I got from this project was huge; 19c for the amount of work I did is tremendous. I learned a lot about the required structure for a flush cut saw, and unexpectedly learned how to make a flexible saw. I get to add twine as a functional design element to my series of hand-made tools. None of the parts I made broke, so it’s positive reinforcement. And as a final silver lining, making the video was a ton of fun!