Do you always fold up your glider in exactly the same way? Something to do with how we fold our wings was brought to my attention recently after testing a relatively new zulu for porosity. Ninety nine percent of the wing was in excellent condition, yet sadly one small part of the leading edge failed the test quite badly! So how can it be that most of the wing was in great shape whilst the most important part of the wing was not safe? The answer is quite simply to do with how it’s owner put his little flying machine away each day. Too many people always fold the wing in exactly the same way. I always tell people to fold up differently. If you fold your wing from the wing tips to the center and then fold it up all along the center the tissue will always get creased in the same places resulting in the centre of the wing loosing it’s enduction much faster than the rest of the material. Another thing that I see people to do is that they fold to the center and whilst sitting on the ground they pull the wing towards them which each fold, dragging the center of the canopy across the grass with each pull. Again, with time, this constant dragging of the nylon across the ground will wear out the coating and cause the porosity of your cherished glider to drop dramatically.
Whilst on this note, it’s also a good idea to concertina the leading edge if you can in an attempt to prolong the life of your stiff mylar cell walls. Maintaining the rigidity of the cell walls is especially important for the take-off characteristics of your wing.