Raingutter Boat Racing - How To Make A Fast Regatta Boat

Making Foam Raingutter Boat Kits

These instructions are for putting foam boat kits together. It takes only a couple of hours at most. Though these boats are simple, they are much better than Boy Scout kits and cost a lot less (15 to 25 cents each). One seven dollar sheet of foam makes over 250 hulls. Packing one of each type of hull together makes 120 kits.


Materials Optional Tools
  • 1 piece R3 Residential Sheeting (polystyrene insulation board) 1/2" x 4' x 8'; buy at a home improvement store for about $7 (available in pink or blue)
  • styrofoam cups - one for each boat
  • Water-proof wood glue; about $8 - this is pretty nasty stuff, it is better to offer it at a workshop
  • Snack-size zip lock bags; seal up a small amount of glue for each kit
  • Paper lunch bags (and staples or tape) or regular zip-lock bags
  • Instruction sheets - 5 cents a copy
  • Utility knife (the kind with a thick handle and retractable blade)
  • 4' Long, straight board or edge
  • Ruler
  • Draftsman's triangle
  • Ink pen


All the work is cutting, squirting glue in a baggy and filling a paper bag! You will cut 16 6-inch by 4 foot foam strips; one for every 19 regular and 13 wide hulls respectively.

  1. Place the foam sheet on a hard floor or table with one or two boards under it a few inches from one end (a concrete floor needs no boards). A carpet will work, but make sure it resists damage by the utility knife.
  2. Mark off a 6-inch strip from the end with the boards under it. The line is 4 feet long across the width of the board.
  3. Place the unused board's edge along the line covering most of the strip.
  4. With the knife blade fully extended, score the foam sheet along the board on the line. It is best to hold the knife vertically with a 45 degree forward tilt. Some pressure on the knife blade against the straight edge is required, so hold the board firmly (or get someone else to). A smooth rapid movement produces best results - don't try to cut all the way through yet!
  5. Score two or three times or until the foam strip separates from the rest of the board. It may be necessary to cut the plastic covering on a separate pass if your blade is dull.
  6. If the cut is straight, use the foam strip to mark another 6-inch line from the same end of the foam sheet.
  7. Repeat the steps above until you have cut all the 6-inch strips you want. One board makes 16 strips at most. The following assumes 16 strips were made.
    Left over board can be used to make decorations for the regatta, especially if the foam sheet is blue.
  8. For 6 of the strips, mark off 2.5 inch blocks. There should be 19 hulls plus 1/2 an inch left over for each strip.
  9. For 10 of the strips, mark off 3.5 inch blocks. There should be 13 hulls plus a 2 1/2 inch hull left over for each strip.
  10. Use the triangle as a cutting guide. 2 or 3 slices with the knife should liberate each hull.
  11. Pour a small amount of glue into each snack-size baggy. You may wish to omit this step.
  12. For each kit, stuff one hull of each size, one styrofoam cup, one glue packet and one instruction sheet in a bag and seal.
  13. Place all kits in grocery bags or large boxes for transport.
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Raingutter Boat Racing - How To Make A Fast Regatta Boat
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