Sawfish Foam Kayak

instructables.com article Sawfish, an unsinkable, lightweight, foam kayak (23 lbs). Free DIY kayak plans, the hardware store boat by rowerwet in outsideboats

To build a sawfish you will need: one 4x8 sheet of 2” XPS, one 2x8 sheet of 2” XPS, and one 2x8 sheet of 1” XPS. (three sheets of 2x8 2” XPS will also work, or even seven sheets of 2x8 1” XPS)

$33 at homedepot.com 2 inch 4x8 sheet

FOAMULAR 250 2 in. x 48 in. x 8 ft. R-10 Scored Squared Edge Insulation Sheathing

FOAMULAR Extruded Polystyrene (XPS) Rigid Foam Insulation

$22.25 at homedepot 2 inch 2x8 sheet tongue and groove.

FOAMULAR 250 2 in. x 2 ft. x 8 ft. Tongue and Groove R-10 Insulation Sheathing

FOAMULAR Extruded Polystyrene (XPS) Rigid Foam Insulation

Stephen Pirsch - POLYSTYRENE

surfersteve.com/polystyrene How to Build Your First Surfboard - by Stephen Pirsch - POLYSTYRENE

When using polystyrene foam epoxy resin must be used to saturate the fiberglass cloth (laminate layer) (most surfboards have 3 resin layers; the laminate coat, hot coat, and gloss coat). Epoxy resin is necessary because polyester resin has styrene in it and will dissolve the styrene in polystyrene foam. Epoxy resin is roughly twice as fracture resistant as polyester resin (not twice as strong) and a little more than twice as expensive. Consider that besides the extra labor, much of the money you saved on polystyrene foam will be lost on the extra cost of the epoxy (See EPOXY).