I just got married, and as is tradition I needed gifts for my groomsmen. I didn’t have the time to get fancy, but I wanted to give my guys something that felt like I was thinking of them when I bought or made it.
I decided to buy a small gag gift and an engraved pocket knife, and present it hidden away in a secret compartment book (or hidden compartment book, or “you put your weed in here” book) that I chose specifically for each of them. I’ll be uploading the video and instructions for that shortly.
Most instructions for making a secret compartment book recommend hollowing out the chamber with an Xacto knife. The process is slow but it’s accurate. The claim is that using any other tool–particularly a power tool–would be too imprecise and leave a ragged edge on the paper. Those folks just haven’t found the right tool yet! My solution was to make a custom blade for my oscillating multi-tool that would handle the task.
What You’ll Need
- An oscillating mutli-tool
- A (preferably old/dull/damaged) oscillating multi-tool blade
- A bench grinder
- Optional: sharpening tools or flat blocks and sandpaper for the “Scary Sharp” sharpening system
Make the Secret Compartment Book Cutting Tool
Making a tool for hollowing out a secret compartment book is pretty easy if you have the right tools, and should take you no more than ten minutes.
Step 1: Grind off the Teeth
The first step is to use the coarse wheel on your bench grinder to knock the teeth off the edge of your blade, and create an edge that’s as close to straight as you can. Be safe!
Step 2: Grind the Edge Smooth
We’re only concerned with the flatness and sharpness of about the last 1/16″ of the blade. Move to the finer wheel on your bench grinder and continue to grind your blade flat. Be sure to check it for straightness before you finish the grinding step! You don’t want to make a blade with peeks and valleys, or it won’t evenly cut your book.
Step 3: (Optional) Sharpen the Edge with a Traditional Sharpening Method
At this point your blade is sharp enough, but you’ll get far better results if you use a traditional sharpening method to bring the cutting edge to a razor-sharp finish using a traditional sharpening method. I use the Scary Sharp method, since it doesn’t require a lot of expensive tools to get started. All you need is a flat surface and a few sandpaper grits from 200 – 1,500 or higher.
Secure the sandpaper to a flat surface. Wet the paper with a spray bottle, then proceed to work the tip of the blade on each successive grit. The end result you’re looking for is a tip with a mirror finish that cuts the hairs on your arm.
Step 4: Make a Secret Compartment Book
Now that you’ve made the blade, you’re ready to use it to make a secret compartment book. That process is worth its own article, so stay tuned! But your new blade will slice through paper like a warm knife through butter, saving you hours of tedious work with an Xacto knife.