|Topic Review (Newest First)|
|12-12-2011 10:02 AM|
Its really not as simple as dacron vs kevlar. Okay, dacron is fairly simple. But even with dacron, different varieties exist, with the latest being "racing dacron." The "kevlar" sail is of course two layers of mylar film with kevlar strings in between.
For racing, the issue is not so much how many seasons until they don't hold their shape, its how many knots. In a gust, the dacron sail is going to stretch more than the laminate sails, and recover less quickly. The laminate sail will hold its shape, or at least deform much less. As the dacron sail looses its shape, the draft will move aft and slow you down, even if you properly retrim for the new apparent wind. If you want to actually have a chance of winning, get the laminate sails. If you don't care so much, then why bother getting new sails at all.
Once you decide you want laminate sails, there are a million things to decide. My first question is, who is making the sail cloth? Hopefully that's the first thing you asked the sail maker. Then you want to know how the threads are being laid out by the designer. If they are just thrown in every direction, you get good stretch resistance but lots of weight. The threads should be laid out by the designer (actually, by his software) to align with the anticipated load paths, so you get maximum stretch resistance where the sail is prone to stretch, with the least amount of thread. Less weight.
Then there is the matter of what the threads are really made of. What kind of kevlar? Is it all the same or do they toss some other type of thread in there? Why? Get the sail maker to explain all this to you.
With the main, find out how much prebend they are designing in and make sure your mast is set accordingly.
Keep in mind, many of these nifty threads are UV sensitive. You can extend the life of the sail considerably by adding a taffeta inside the laminate. This cuts the UV from one side, and will do more than you would expect to slow wear.
When you make these decisions, remember that the #1 hits the mast when you tack, but the #3 probably does not, or at least not nearly so much. So, the #3 can use slightly more brittle strings (maybe a little carbon) but the #1 needs more durable strings. The #3 is probably used in heavier wind, so you want it stronger. The #1 in lighter wind, maybe very light wind, so you want it lighter.
Once you have these, take good care of them. Flake them carefully after each use. Don't let salt dry on them. For cruising, use the old ones.
If you like, let us know what the sailmakers plan is and we can give you questions to torture him with. And whatever happens, make very sure he comes out to measure the boat before he gives you the quote!
|12-11-2011 12:48 PM|
thanks for replies,
im leaning towards the Kevlar as its not much % difference and will swap sails when cruising to help keep the new sails fresh, the slight weight difference appeals as we may need to change headsails during a passage race occasionly.
I just need to check there's no handicap penalty for using Kevlar in club racing
|12-11-2011 02:37 AM|
|overbored||If you race then Kevlar, if you day sail then Kevlar, if you enjoy sailing and the look and feel of a properly trimmed sail then Kevlar. they will last longer and they will hold there shape longer. the new materials they are using today are way better then when they first started making laminated sails. Delams are not happing if you take care of the sails and keep them stored out of the sun. Kevlar cost only a little more as the labor is less to make the sail. and they don't really make many with real Kevlar any more but they use other types of arimids that look like kevlar but work even better. as for weight yes there is a big differance, the first time you pick up the bag you will notice.|
|12-11-2011 01:46 AM|
The major difference will be in the longevity of sails made out of the different materials. It is very simple. Dacron will not hold its shape as long as the kevlar. The dacron will look ok for perhaps 10 or 12 years, despite being blown out of shape after two. The kevlar will start to delaminate and disintegrate after three years. You may be lucky if you can still hoist the kevlar sail after 5 years without it blowing apart. Since you're paying, you get to pick the sail you want.
In such a small boat, the performance difference between two NEW sails of different materials will be minimal. If both materials are cut to the same design, they will perform similar to each other, as long as they hold their shape(s). Sails on a 8m boat are simply not big enough for the materials to make a big weight difference. If the mast was 100' tall, THEN, there'd be a weight difference, which might have an effect on performance. Hope this is helpful information to you.
|12-10-2011 03:15 PM|
apologies for typo that should read 26ft (8 meter) yacht
40 views & no replies, talk to me pleeeease....!
|12-10-2011 02:25 PM|
crimpless dacron v kevlar for cruiser racer
Hi looking at quotes for our 1979 16ft sloop cruiser racer, looking at tri radial cut crimpless dacron versus x tec kevlar.
Any thoughts as to what the performance difference would be?
we are looking at a new mainsail a no.3 jib & no.1 genoa