I needed to develop a plan to foamsmith flatblade boffers that I could teach other kids to do, that could be completed in a single workshop, and that used affordable materials. My final plan is detailed below (draft version — I am adding good photos from the design process).

Supplies

• • • scrap cardstock for templates
    • blue foam camp mat —½-sheet per boffer
    • ½-inch CPVC pipe — 40 inches per boffer
    • ¾-inch CPVC pipe — 8 inches per boffer
    • 1-inch washers — 2 per boffer
    • Liquid Nails adhesive
      • This was a disappointment as it simply would not dry. If I was to do this workshop again, I would find an outdoor space or well-ventilated indoor space and use contact cement. I chose Liquid Nails because we were foamsmithing in a church basement with limited ventilation options and Liquid Nails has Greenguard Children & Schools Certification. It is VOC-compliant with no harmful fumes. It seemed a safe choice. 
    • duct tape, basic grey and assorted patterns
    • open cell sponges — 1 per boffer
    • electrical tape in assorted colors

Tools

• • yardsticks — 8 per boffer (I happen to own a lot of yardsticks; you can probably use something else is step #29)
  • clamps — 4 per boffer
  • markers (the basic black Sharpie works well) — 1 per maker is useful
  • scissors (for cutting medium density foam rubber)— 1 per maker is useful
  • tape measures (sewers aka soft) — 1 for every 2 makers is useful
  • rulers (the yard sticks will do, but shorter rulers are handy if you have them) — 1 per maker is useful

Instructions

• 1. Choose your blade width.
     • A minimum blade width of 3 inches is required for safety.
     • You can change your mind about this later, but you need a basic idea to do Step #2 well.
  2. Using the width of your blade, design your crossguard (also called your quillons) and make a template on scrap cardstock.
     • A good overview of crossguard styles is at “Ewart Oakeshott: The Man and his Legacy: Part IV,” an article by Chad Arnow, Russ Ellis, Patrick Kelly, Nathan Robinson, and Sean A. Flynt, compiled and produced by Nathan Robinson on the myArmoury website.
     • “How to Make Glamdring from Lord of the Rings – Gandalf’s Sword” from Storm the Castle includes a template for Glamdring’s crossguard. The template is intended for a foamboard prop, but it will work for your boffer. I used this template for my first boffer. I also made the foamboard version of Glamdring: 
     • The stock or head of the T-square makes a simple sturdy crossguard.
  3. Measure your crossguard height (from grip to blade). You’ll need to know this for determining the length of you core.
  4. Design your pommel and make a template on scrap cardstock.
     • Pommel strikes are not allowed in boffering, but pommels must be padded for accidental hits.
     • The end of your pommel should not be able to pass more than a ½ inch through a 2-inch round hole (that is, an eye socket). 
     • A good overview of pommel types is at “The Sword Typology of Alfred Geibig,” an article by Christopher L. Miller on the myArmoury website.
     • While you can get fancy, three layers of a simple 2½-inch to 3-inch circle of blue foam camp mat will work fine.
  5. Choose your grip length
     • Grips are generally 4 to 6 inches, depending on your hand size.
     • Grasp a yardstick or ruler to measure your grasping hand and add about an inch for comfort. I have a 4-inch grasp, so I want to cut a 5-inch grip. 
     • Double check your measurement!
  6. Work with a partner to measure each other’s leg length from heel to hip.
     • Double check your measurement!
     • Your boffer length from point to the start of the pommel shouldn’t exceed your leg length, and shorter is not a bad idea for better balance.
       • Your pommel may be extended for balance.
  7. Using your leg length as a guide and knowing your grip length, and your crossguard height, choose your blade length.
  8. Add your blade length (from step #7) to your grip length (from step #5) plus your crossguard height (from step #3) and subtract 4 inches (for a soft blade point) to determine your core length.
  9. Mark a ½-inch CPVC pipe with your core length.
     • This is the danger point where mistakes are made! Pay attention to step #8! You are not cutting your blade length, but your core length.
     • Your core supports your grip, crossguard and most but not all of your blade.
     • The final 4 inches of your blade will be 1 inch of blue foam camping pad plus 3 inches of soft sponge to ensure a safe point.
  10. Cut your 4-inch to 6-inch grip from one of the ¾-inch CPVC pipes.
  11. Attach a 1-inch washer to one end of ½-inch CPVC core:
      • Rip a 6-inch length of ordinary duct tape.
      • Rip that in half lengthwise to make two narrow strips.
      • Place one strip over the other to make a cross.
      • Center your washer in the center of that cross.
      • Center one end of your core on the washer.
      • Use the duct tape to secure the washer to the end of the pipe, pressing the duct tape flat over both washer and core.
      • This will provide support for your grip and prevent the sharp edges of the CPVC from cutting through the foam of your pommel.

        

  12. Slide your ¾-inch grip over the uncapped end of the ½ core and snug it up against the washer.
  13. Secure your grip on both ends by wrapping once with ordinary duct tape. 
  14. Now attach another 1-inch washer to the other end of your core, using the same method as in step #11.
  15. Cover the entire length of your core in ordinary duct tape, using a single lengthwise piece of tape or two
      • Do not spiral the tape around and around the core.
      • This is to help prevent splintering should your boffer break in combat.
  16. Take a break! Clean up your workshop, wash your hands, and eat lunch.
  17. Study the Blue Foam Camp Pad Layout.
      • This step is critical. Have a plan before you trace. Be sure you have a complete plan before you cut!

        

  18. On half of a blue foam camp pad, trace your crossguard template in the lower left corner with the hilt snugging the left edge of your crossguard up to the left edge of the pad.
  19. Center your core over your crossguard outline with the top edge of your grip at the bottom of your crossguard and mark the top edge of your core. Now make a mark 1 inch beyond the tip of your core — this will be the top of the foam portion of your boffer.
  20. Using your blade width from step #1, measure out half the width of your blade from either side of the center of your traced crossguard.
  21. Draw your blade shape.
      • Keep in mind that complex shapes will be harder to cover in duct tape.
      • Use a yardstick edge to make the sides of the blade straight.
  22. Use scissors to out the crossguard-and-blade as a single piece.
  23. Study the Blue Foam Camp Pad Layout and then use your first crossguard-and-blade as a template to trace two more, following the layout above.
      • Measure twice, cut once! Trace both the third and fourth crossguards-and-blades!
      • Take a good look at that Blue Foam Camp Pad Layout again and notice that you’ll also need to leave room for 2 more crossguards and your pommel pieces.
  24. You’ll need a ½-inch channel through the center of one blade-and-crossguard to fit around your core.
      • Study the Blue Foam Camp Pad Layout.
      • Find the center of one blade and measure ¼-inch out from either side of the center.
      • Once again, center your core over your crossguard outline with the top edge of your grip at the bottom of your crossguard and mark the top edge of your core to mark the top of your channel.
      • Use a yardstick to draw a straight line, leaving the 1-inch of pad above the core!
      • Cut out the channel using scissors.
      • You must have at least 1 inch of pad above the core, to be followed by at least 3 inches of soft sponge.
  25. Place the core in the channel you cut and secure it in place with two 4-inch strips of ordinary duct tape on both sides of the pad (using 4 strips of tape).
      • Don’t cover completely with duct tape! Just tack it in place.
  26. Use a scissors to trim the edges of the other two blades into an angle.
      • If you wish, you can draw lines about ¼ to ½ inch from the edges to help you cut straight.
      • This is much easier to do with a hacksaw once all 3 blade pieces are glued together, but I didn’t have enough hacksaws to share and worried about accidents.
  27. Apply a thin layer of Liquid Nails to one side of the pad-and-core piece and another thin layer to inside of one of the angled pad pieces. Wait 3 to 5 minutes, then press the two pieces together.
  28. Turn it over and repeat the thin layer of Liquid Nails on the other side of the foam-and-core piece and on the bottom of the other angled piece. Wait 3 to 5 minutes, then press those two pieces together.
  29. Use 8 yardsticks (two on each edge of each side) and 3 clamps on each edge to hold your pad together over your core. Let the glue set for at least 30 minutes (overnight is better). When the glue is set, remove the clamps and yardsticks. If your glue is not fully dry, use a short strip of ordinary duct tape to secure your pieces together at both the top and near the crossguards. Do not over tape! Just tack it in place!
  30. Clean up your workshop, wash your hands, and go have a snack.
  31. Trace and cut out two additional crossguards. Glue the crossguards in place on your boffer as in step 27, securing with a thin strip of ordinary duct tape.
  32. Trace and cut out at least two pommels. Pommels must be a minimum of 2 blue foam camp pad layers thick, but your design may call for more.
  33. Stack together your pommel pieces, glue as in step 27, and secure them loosely in place at the end of your grip with a couple of thin strips of ordinary duct tape (just like you did the washer).
  34. Design your point. You can make a template on scrap cardstock or draw directly on your sponge.
      • The base of your point should be as wide as the top of your blade.
      • Your point must be at least 3 inches long.
      • The stabbing tip must not be able to pass more than a ½ inch through a 2-inch round hole (that is, an eye socket).
• Use a scissors to snip out the form of your point from your all-purpose sponge.
• Attach your point to the end of your blade with a few strips of tape, being very careful to not wrap tightly so that you do not compress the soft and springy foam!
• Choose your finishing duct tape for your pommel!
  • Secure your pommel to the end of your grip using the same method as in step #11 for the washers.
  • Then cover the entire pommel, using smaller, narrower strips to cover tricky bends and curves and then covering those with larger pieces to keep them from peeling.
  • Take your time, and apply each piece as smoothly as you can.
  • Avoid more than 3 layers of tape if you can avoid it.
  • Do not cover your grip in tape any more than needed to secure your pommel!
• Next to be covered is the crossguard. Choose your finishing duct tape and apply using the same method as for the pommel.
  • Choose your placement carefully and cover the entire crossguard, extending about ¼-inch out onto the blade and grip.
  • Avoid more than 3 layers of tape if you can avoid it.
• Then the blade. Use long lengthwise strips — don’t spiral around and around!
  • To keep your sword soft and safe, avoid layering duct tape more than twice over any area.
  • Avoid compressing the soft foam of the point.
• Last is the grip, using two layers of either duct tape or, preferably, electrical tape.
  • Here you may wrap the tape around and around in a spiral, which creates a nice effect.
• Check your point. If it’s too stiff, use the point of a safety pin to poke a few breathing holes in the duct tape.
• Before you hit anyone else with your boffer, you need to test it on yourself.
  • Take your outside and, with your parent’s permission, whack yourself in the leg so you know how hard you can safely swing your boffer in mock combat.
  • Don’t hit as hard as you can! Just hit yourself as hard as you plan to hit your opponents in mock combat.