I have a 10 meter Windwing Syntesis with a composit mast. If you overpower (I have a crank), you get too much luff at the top of the sail. Too much luff in a stiff wind shatters mylar. Any ideas on a patch? I've used steel duct tape in the past, but it's ugly.

Rolley, I typically have problems with the very top panel and also the panel where the boom is. Lots of downhaul makes a 9 or 10 m sail handle lots of wind (I was in winds gusting over 30 on Sat with a 9.0) and still pretty fast - so I pretty much always rig with lots of downhual using a crank. The problem seems to be when you tack in the high winds and the top of the sail flutters and this is hard on the sail. New sails seem to hanle this ok but after they are a few years old, the cheap monifilm material starts to get brittle from UV exposure. The "problem" is that you CAN sail a 9 or 10 m**2 sail in those kinds of winds so I end up doing it all the time.

Ive tried a lot of things to repair the sails - none pretty but Ive gotten over that.. Here some of the things Ive tried

1. Ive used fiberglass boat tape and contact cement to repair a sail and this seems to work fairly well but looks bad and UV will eventually cause it to get brittle and yellow. So Ive then put the shelve contact paper over the panel (I have one sail with fake wood grain contact paper on one entire panel - still going strong but looks like hell). The contact paper stick better if it and the sail is sprayed first with something like 3M spray on glue. I always check glue first to see if it will disolve the plastic mylar. Ive used the fiberglass boat tape and contact cement to repairs on land sailing trips and it gets you back sailing quickly.

2. On several sails, I took thin rip stop nylon and basically glued it to the mylar material using the 3m spray glue. It works fairly well and seems to protect the panel but the edges of the rip stop nylon keep wanting to fray loose because of the wind flow. You could possibly also do this with the shelf contact paper and even though it will stretch, it keeps UV off the sails and this seems to make a difference.

3. Ive heard that the real sticky carpet tape works well - also looks bad..

I like windsurfing sails but if someone built a modified one using better material (extra weight wont matter), a little higher aspect and better cut on the bottom to close the gap better and designed around a stiffened mast, Id be plunking my money down..

One experiment gone bad.. One time I took an older sail and thought that maybe I could spray it with a urethane varnish or something like that because it had a UV inhibiter. Fresh monofilm is fairly strong so I was hoping to just preserve it from UV. Pretty soon after a sprayed on the coating, the monofilm started to develop lots of cracks and pretty much just fell apart..

Here is a picture of my "ugly" repair job. I use this sail for landsailing so that I dont worry about UV damage but the sail still really works well. I think Im getting pretty close to an honest 10x wind range from this single 9.0 sail. When its set full, it goes in some really light winds (like maybe 4-5 mph winds) and this last weekend I used it in 40+ mph winds with a lot of outhaul. I got the boat up to 63.3 mph GPS (my wheel speedometer said 63.0 mph) at Smith Creek last weekend which is the fastest Ive gotten a sail that big (9.0 m**2 up to). Pretty cool landsailing with the snow capped mountains in the background

The next picture is of the pucker mounds at Smith Creek Nevada which in my opinion is one of the funnest places on the planet to do any sort of sailing..

wh

Just missed you. We'll have to get coordinated some time. Good speeds! Was out there May 17 to 19. Saw no humans, which is a good thing when sailing in a duststorm brownout. Got to chase a jackrabbit through the mounds. A series of flats sent me packing. Am having doubts about nylon rims. Patched up the 10m**2 with 4 yards of denier 600 (burgundy) and 3 quarts of contact cement. Bomb proof but a little floppy. Am thinking of one of those 12m**2, for plowing snow mostly. And all white seems right.

Rolley, maybe you got to see the Winjet out there? The day I got there, I got to see it sailing but didnt get to check it up close after it slid out on some mud going real fast and they put it in the trailer (details - http://www.windjet.co.uk/ ) When it got real windy and I was out just "fricken flying", Winjet was going over 40 mph faster than I was... Bob Dill the current landsailing speed record holder was also out there (without the Iron Duck) so it was a real treat all around. Also cool for my sons to meet these guys.

Regarding rims/tire and pucker mounds, the first day I was there, I was using 15 inch OD ribbed tires and the Azusa aluminum 6 inch by 4 inch wide rims. These have three 5/16 bolts and I replace them with grade 8. When Im jamming turns (you understand what Im talking about if youve gone into the pucker mounds going fast), I sheer the grade 8 bolts - replaced three of them in one day. I then went to some 12 inch diameter slicks with the same rims and these stand up to some nasty torture but I can tell that they are slower on rough ground in lighter winds (but they sure are fun in higher winds..).

My current config is not bad but to get optimum performance, I have to change tires from low to high winds. Im looking for "one solution" and think some slicks about 15 inch diameter and about 5 or 6 inch wide might work well. The 16-650x8 tires at this web site look like they might be good:
http://www.gokartnminibikeparts.com/slicks.htm

But I still havent found any rims for them. Asusa makes an 8 inch AL rim that I would not trust at all for this application.. Any leads???

wh

I just ordered some 6" aluminum Tri Star wheels from http://recreationalmobility. Was sold on the roller bearings. Their 8" rims (Aluminum Spinner) look a bit wimpy. The fact that you shear lug bolts indicates some serious forces going on. I think my torn tube problems (6 times) may be related. I still have the 10" rims that came with the boat. I may get them out of mothballs now that I've beefed up the hub assemblage. Nobody but me at the lake. I take it that Windjet didn't get their speed record, this time around.

Woops, mispelled Windjet..

The 6 inch Aluminum Tristar rims are overall pretty good and I think you will be happy with them. Its the same rim Manta's have used for a "long time" and Ive been overall happy with them and I tried a lot of different tires. They are the ones that I sheer the bolts on when used with the 15 inch tire but only when Im really abusing them (like throwing the boat into a power slide in high winds). I pretty much dont have any problem when used with the 12-600-6 slicks (11.8 inch od). The smaller od tire has more drag and bumpier ride on rougher surfaces and Smith Creek had some rougher surfaces this year but the smaller diameter also handles the high side loads better. I like slicks for several reasons but one important one is that Ive found them to be significantly less suspectable to getting flats. I didnt get any flats at Smith Creek with any of the tires I used but have repaired a LOT of flats from sailing at a particular and very unusual dry lake bed in Wymoning (its more similar to sailing the pucker mounds than to other dry lake beds but its a really fun place to sail). The Wyoming dry lake bed gives flats from bush "stems" going through the tires but the slicks seem to handle this well. Slicks probably slide a little more sideways than the ribbed tires do but its hardly noticable. The slicks also wear well on pavement. Parking lot sailing pushes the "safety" aspect a little bit but slicks also just really turn nice on pavement.

Ive also only used ball bearings and havent really had any problems but the tapered roller bearings should be better. They are supposed to be better at handling side loads which seems that if Im breaking the grade 8 bolts, probably is important.