Boffer swords take practice to make. The materials can usually be found at any hardware store and are inexpensive. The construction process is simple to learn, but does take some trial and error and experience to master.
Let’s start with the materials:
3/4 inch CPVC pipe (24″-36″ Short Sword / 34″-46″ Long Sword)
Pipe Insulation (minimum of 5/8″ thick)
Open cell foam (~2″ thick)
Duct Tape
Razor or Scissors
Hacksaw
Electrical / Sport Tape
If you can avoid it, don’t split the pipe insulation, as it allows the core to break out and possibly injure someone.
Step One: The Blade First, cut the CPVC pipe 4 to 6 inches shorter than the desired length of the sword, including the hilt. Tape both ends of the pipe to prevent it from ripping the foam later. Slide the pipe insulation on the pipe and secure one end to where the blade will start. Fasten it securely with electrical tape. The insulation should extend past the pipe at least 1/4″ but not more than 1″. Now cut a small piece of closed cell insulation to fill the hole at the tip.
Step Two: Tape Using duct tape lengthwise along the blade, cover the length of the sword. Do not spiral wrap the tape or compress the foam in any way. Lay tape lengthwise only.
Step Three: The Cross-Guard If you want a cross-guard on your sword, you would build it now. Cut a 12″ piece of pipe insulation. There is usually a slit in the foam on one side. Open the split of the foam at the exact middle of the piece, and cut a hole in the opposite side. Then slide the foam up the hilt and secure it in place. Apply tape to the cross-guard similar to Step Two. How to build a larp-safe boffer sword
Step Four: The Hilt Now cut a short piece of insulation, about 3″-4″ in length. Slide this over the bottom end of the sword so that it hangs over by at least an inch, same as the tip, and secure it with electrical tape. Fill the gap with foam and tape it lengthwise, similar to Step Two.
Step Five: The Thrust Tip Next, cut two 2″ sqares of open cell foam. Place one at the tip of the sword and gently lay duct tape over it, securing it to the blade. Take special care to not compress the foam while doing this. Repeat this step with the hilt of the sword. Then, with a pin or needle, punch hundreds of holes in the tips to allow air in and out. When squeezed and released, the tips should spring back into their original shape almost instantly. One way to increase the durability of the foam in the thrusting tip is to wrap the foam in tissue paper before taping it.
Step Six: The Grip Spiral-wrap electrical or sport tape around the the grip of the hilt, covering it completely. You’re finished!
Information from : http://www.friendsliketheseplay.com/project/build-larping-safe-boffer-swords/
