picked up a second hand gasstra sail ,a few years old at least ,used it half a dozen times and just blew out one of the mylar panels completely,is this an age thing or do new sails do this as well,cheers.
If it is mylar it is waaay older than a few years and yes it is kangaroo edward.
But do u mean monofilm?
Yes. Are you talking about a mylar sail, where the film is bonded to a solid backing fabric? I have found that with old mylar sails, even if they are not used and stored dry for many years, they usually will delaminate and fail once they are put to any significant use. Probably more than a few years old I'd reckon if it is mylar 
Clarence
I've used those old Mylar sails for farting around and teaching in less than 12knts.
Yes they do come apart, at least the pre-87 or so old stuff. Almost as you unfurl them.
Funny, just 10 years ago they were still OK. I take it there's a use-by date on this real old stuff.
I found a mylar Wally sail that had not been used much, looked new,
fell apart the first time I used it.
someone here used the term chip-packet to describe it, thought that was pretty accurate.
I do have a couple of warp-speeds that seem ok.
the mylar is single film no laminate, its a gaastra gtx 7.0m,i think its a 2008 ish but didn't seem that used, just a bit of fading ,the mylar seemed quite thick and looked like it might crack or split but not explode like it did, the impact was moderate.i still sailed it in but I wasn't that far out ,maybe I need to invest a bit more before I start venturing offshore? monofilm?
^^^ that's monofilm.
Any creases that you can physically feel or look like a white line are serious, a good hit will make it split and it will run to the edge of the panel (explode)
So in an old sail, tape up the bad ones to get a bit more life out of it. Clear mylar tape will work well and be almost invisible.
If you have say a 50cm long split in a panel, lay the sail flat on your floor, clean well with metho. Let dry, then tape with cloth reinforced gaffa tape, making sure the split edges line up well. That sail may well go another season or 10.
sweet, will do mark,but I think this sail is finished anyways or I could trim the remainding film out and say it has factory air cond no one will even know
i have been using Bear All Weather Tape, also works on SUP rails, bicycle frames etc..
www.bunnings.com.au/bear-48mm-x-25m-clear-all-weather-tape_p1661582
Uv kills mono. If one panel has exploded chances are the others aren't far behind.
Select to expand quotemort69 said..
I could trim the remainding film out and say it has factory air cond no one will even know
OK
Cut the remaining monofilm out of ALL panels neatly with a razor blade
Lay flat on a shiny floor, like good varnished floorboards......and take a photo. It will look like it is brand new.
Advertise on eBay as "current sail as new, for $500".
Some numpty will buy it.
I paid $90 for it,guess im the numpty.mabey ill treat my sails with a bit more respect from now on.
Select to expand quotemort69 said..
I paid $90 for it,guess im the numpty.mabey ill treat my sails with a bit more respect from now on.
I'd not say that. $90 for a 2008 race sail is not bad at all.
Plenty of peope have a 1y/o wave sail worth $400 plus and a CREASE in the mono is a weak point and a panel blows out in a crash.
