Sargon, I built my two kayaks almost exactly like you built your pontoons except the inside frame stations are taken out. First the hull is stripped, sanded and fiber-glassed. Then turned over and the deck is built the same way. Then the hull and deck are separated, the stations taken out and the insides are sanded and glassed. Then the hull and deck are mated without the frame stations which make the boat lighter. I could see building just one pontoon like yours for a south sea type outrigger for my longer kayak.
John
