John,

Scooby is correct. If you dont have a full 50mm overlap in the cloth at the only horizontal seam the sail will not last long at all. Trust me I can tell you by experience.!!! Mylar sails can take some high loads depending on the fibre configuration, but stitching across the load of the panel will just pull through the fabric with out the assistance of some sail number ( or sticky back) to help hold the mylar together. If you look at some sail with a similar panel layout you will notice up to 5 runs of stitching just to keep the seam together.!!

While on this subject it will be interesting to see how many sailmakers will succeeed with the new contender "Maxx" fabric, as all seams will be cross cut & subject to high loads. Rolfe may be able to give all an idea on how he has approached this issue.??

A fellow had one made here ( a cross cut mylar sail with contender maxx febric)in Adelaide by a reputable sailmaker & against my advice he did not treat the cross seams with respect & the sail became flatter & flatter each time he sailed as the tapering in the seams were "straightening out" & the sail was a board & inverting in meduium to high winds. Needless to say the sail was only used 5 - 10 times & now useless.



Regards

Marcus