Arne wrote:
Asmat,
I would not blame the sailcloth here. To me it appears that the boltrope at the leech has been way too weak, or even non-existing. This has pulled the shape out of the panels, in particular on the upper ones, where the loads are highest. I once wrote a note on that when I discovered that the webbing for my Johanna’s sail stretched too much. The remedy was to hand-stitch on a second boltrope (a length of old halyard.).
Arne
Yes, I'm seeing a stretched leech in the upper four panels, but also poor shaping of the lower panels with the draught too far aft, and stretch in the body of the cloth of the top two panels. There could have been a little more tension on the THP to get rid of the diagonal wrinkles, but this would not have made the sail look as good as it should - it's clearly stretched out of shape. I lay the blame chiefly on the cloth, with its loose weave and large proportion of filler resin, but partly on the design and construction of the sail.
I think I remember that Donald Ridler crossed the Atlantic with JR sails made from old bed sheets, so poor quality cloth can be used, but really needs to be paired with good sailmaking technique, laying the cloth in the correct direction with warp/weft in line with the loadings, and adding patching and reinforcing where needed. The latter would include a wide doubler down the leech and multiple patches at corners and batten ends.
All in all, Odyssey doesn't seem to be a good choice, amongst the cover-type materials. The slightly heavier ones, Weathermax, Top Gun 9, Top Notch 9, Surlast etc seem to be more firmly constructed.
Scott, that Polyester Ripstop that you found is unbeatable on price. It could be used, but only with due regard to design and construction, as noted above. It won't make a world-girdling sail, but should be good enough for light duty summer leisure sailing.