Halloween has been a pirate theme around here for a while. I had the sword, I had the treasure chest, I needed a cannon. More than just a prop, this cannon will fire a potato slug a couple of hundred yards. For Halloween we dialed back the psi and shot harmless "cannonballs" made from tissue paper filled with baby powder. The result was a VERY popular addition to the pirate party we had.
Step 1: Build the Jig
The jig is made from 2X4 and MDF. First I determined the diameter of the front and rear of the finished cannon and the overall length I wanted. I then drew the profile out on a sheet of MDF and cut the profile out with a jigsaw.
Then I split the profile in half to attatch to the sides of the jig. This profile would provide the template I would use to carve out the material.
A piece of 1.5 inch Schedule 40 PVC is used to lay up the layers of foam and will also act as the barrel.