One of the first things, they did after Landing was started was to start making carbon Based Plastic, which Pol Nietro, noted that Thread has effected the first building they put up, but not the silica based ones that were put up later. The ships that were brought to Pern where made of silica plastic, in number parts, like Jim Tillek's Southern Cross as an example, during the Second Crossing, the fire lizards protected the deck of his ship that had imported teak wood as part of his weight allows as captain, Thread would melt and gorge thinner plastic.