Jay: Back in my wooden kayak building days, I made some very light and very cheap paddles starting with a 1 x 2 from Home Depot and the same 1/8″ 3-ply “door skins” I built the boats from, plus some epoxy to join them and varnish to coat them. For ultimate low cost and lower than commercial paddle weight, I’d again start with a knot-free 1 x 2, jigsaw a curve for each blade, round the edges, and affix corrugated plastic sign material (“Lose 30 pounds in 30 days!” or from your least favorite political candidate) for the blades themselves. About $3 of parts.
I prefer a more “Aleut” style of paddle with longer narrower blades for flat water. They have plenty of propulsion once under way, although not as much initial thrust (which is important for white-water kayaks)
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