This is my first attempt at submitting an Instructable. I decided to go with this super simple, super cheap, and extra tough pumpkin carving tool.

Step 1: Gather the Parts

The parts list is really simple:
2-4" long piece of copper tubing (I used 1/2")
Course toothed Jigsaw blade

Step 2: Clean Inside of Tubing

I cleaned the inside of the tubing with a small wire brush. This facilitates sweating a little solder in later to firm up the assembly

Step 3: Mark the Blade

Put a mark on the blade to show that it is sufficiently installed. I made sure to go a couple of teeth down. This makes the teeth dig into the couple and made for a stronger joint. You can see my red mark in this picture.

Step 4: Squeeze the Copper

Mount the copper tubing in a vise by about 1/2". Squeeze the jaws down until there is just enough room to insert the blade. Then insert the blade to your mark and squeeze the copper the rest of the way down around the blade. I positioned the copper in the vise a couple of times to crimp just off the edge of the blade to get a tight grip on the blade.

Step 5: Sweat the Opening

Using traditional soldering techinue, I sweat some solder into the joint. This keeps it from working open and loosening around your blade. My first attempt did not include cleaning the inside of the copper, so this step wasn't possible. It probably isn't totally necessary. You can always tighten it back up in the vise if it works loose.