I have been planning remaking the sail for the Revolution 1.5 SUL (Super Ultra Lightweight) for some time now as its getting rather old & saggy. So I purchased some Ventex polyester fabric in order to get on & do this - with a nice blue, green, white and orange design in mind. However there was no Ventex in white and I didn't want to pay for icarex (approx. twice the price), and I ordered a very fluorescent orange which would look awful next to the blue and green! So I changed it so it was just green and blue.
Once I had cut the pieces and stitched together (using simple flat seams & glue as usual) I noticed that on one of the panel's I hadn't added the double seam allowance - needed to accommodate the leading edge. The difference was about 1cm - enough to be noticeable.
So what to do?
First thought was to trim down the rest of the leading edge to make it the same. This I didn't like as I felt a) it would be difficult to do (the leading edge is 250 cm & my table is much less), & b) would take some of the surface of the sail (but admittedly not much!). Second thought was to sew a small panel to make up the shortfall. This seemed the better (if messy) solution.
So I cut a piece of Ventex to fit - leaving a 1cm overlap with the surrounding 3 panels, & a couple of cm extra on the leading edge side (see left)- so I could trim it afterwards. Stitching this was difficult, given it was quite small, but once in place it looked good (see right).
I hoped that once I had stitched the leading edge gauze & done the double fold the extra panelette I added would be more or less invisible. Which it was. I like it when a plan comes together!
The rest of the sail construction was fine - I had found some dark blue Dacron for the leading edge itself - a bit narrow - but fine for the SUL spars (so no sticking in the thicker SLE spars then).
The spar fittings were made (as usual) from white PVC tubing from B&Q (a UK Diy / hardware shop) with an internal diameter of about 8mm - that 'about' is important as the external diameter of the SUL spars is also 'about' 8mm. And those two 'abouts' are not the same! I checked the fitting of all the end caps with one of the SUL spars & they all fitted perfectly-so I attached all the end caps to the sail, fitted the spars in and.....
....all but one spar didn't fit! and the spar that did fit was the one I had used to test. I wasn't impressed! So I had to take off all the end caps and carefully drilled out some plastic to make them fit.
The important question is this: How does it fly?
The short answer is 'fine' - not brilliant but not bad. As this was the first time I had used Ventex (which I found harder to work with than standard ripstop nylon) I ended up making some errors with the tension of the sewing thread which resulted in quite a baggy kite (although this could be in part due to the asymmetrical sail panel layout I had chosen). This manifest itself by having a trailing edge that can flap a little and a loss of performance in reverse flying. In comparison I also feel that the near zero wind flying isn't as good as the official sail. But it's adequate for my needs at the moment - I do intend to revisit and improve the SUL at some point but in the meantime this is fine.