How Long Do Modern Sails Last ?

[nickjaxe]

Hi all...my first post this forum,

I am not a sailor but into microlight aircraft that use more or less the same sail material for there wings as modern sail boats sails are made from,

In recent years the material does not seem to be as long lasting as the material of say 10 years ago...being badly affected by UV radiation,

Just wondering how modern boat sails compare life span wise in this respect....with aircraft we under go an annual test of the wing material that tests its resistance to ripping....I wonder do sailing boat sails undergo similar testing.

Regards Nick.

[cburger]

There is no one answer to this question. Longevity of a dacron sail will depend on a number of factors such as quality of the initial construction, weight of fabric used, how hard the sail is used, are sail covers utilized as well as the latitude the boat is used in.

[nickjaxe]

I see thanks for that....is UV degradation a major problem I wonder.

Nick.

[sailcruiser]

Originally Posted by nickjaxe

I see thanks for that....is UV degradation a major problem I wonder.

Nick.

It can be. That is why we have covers on everything. Location is a big factor too. For example my sails will likely (under identical and equal use) outlive a Carribean or FL sail just because of my northerly location. UV is definitely not a sail's friend. I assume you're using some weight Dacron? Or more the Kevlar?

[nickjaxe]

Its Dacron....mine is over 12 years old and it still ok but it the owners of newer aircraft who are having problems....some failing in less than 2 years,

Seems the modern stuff doesn't have the same resistance to UV unfortunately....I wonder why....anything happening in the boating fraternity like this.

Nick.

[sailcruiser]

Originally Posted by nickjaxe

Its Dacron....mine is over 12 years old and it still ok but it the owners of newer aircraft who are having problems....some failing in less than 2 years,

Seems the modern stuff doesn't have the same resistance to UV unfortunately....I wonder why....anything happening in the boating fraternity like this.

Nick.

There are a lot of variables to consider. If this is a manufacturer type situation they probably sub it to the cheapest bidder. With sails it's often a get what you pay for. There are sails made worldwide some good some garbage. It all depends on he fabric chosen and attention to detail ( like using thread that stands up to uv). SC

[SteveT]

I don't know about in the US but here in the UK there are now a lot of 'cheap' sails available made - where else - in China. Like so many other things made there the quality of the basic cloth is suspect and you may well find that newer wings are made from cloth from China. We also have some manufacturers who have the sails made up in China but stress they are using a European / American produced fabric. In the course of my work I have had a lot of bad experience with Chinese manufactured goods to the extent that now we specifically exclude Chinese products from our tenders. in the short term we pay more but at least we get some use out of the gear. Sorry if I have gone a bit off topic here......

[nickjaxe]

Steve I also am from the UK...so your point may hold some water.

Nick.

[Rakuflames]

Originally Posted by nickjaxe

I see thanks for that....is UV degradation a major problem I wonder.

Nick.

It would be except that virtually all sailboat owners keep their sails sheltered from the sun when not sailing. That may not be practical for a plane but very easy ways to do that have been developed for sail boats.

[DaveOnCudjoe]

Perhaps the question could be visited by those circumnavigators in the group. How do sails hold up to the day in day out exposure experienced in long passages? Can you get a circumnavigation out of 1 set of sails? Dave

[mrohr]

Color counts. Dark colors resist UV much better than white and will last longer if all other factors are equal. But of course sailors cover up when not in use.

[Jim Cate]

G'Day Nick,

First, are you sure that your wings are covered with Dacron? I'm not an aviator, but the few wings that I've seen appeared to be covered with a cloth similar to spinnaker material which is Nylon based, and which has poorer UV resistance. And whichever material it is, what weight cloth is used?

And secondly, the above post that says that darker colors have better UV resistance than white disagrees with my info.

Thirdly, in the failures, is it the cloth or the stitching that is failing?

Finally, are the wings left exposed to sunlight while the aircraft is not in use? UV degradation is indeed the factor that will limit the lifetime of the cloth in normal use. And FWIW, dacron sails last for a lot of use/exposure hours. We have typically gotten at least 7 years and 40,000 miles out of our primary sails. At that age the shape has become compromised to some degree, some stitching will have been redone, but the cloth still retains enough strength for practical usage. We do cover the sails when not in use.

Hope this might help.

Cheers,

Jim

[Sailcat]

I would like to add my two cents. I was a chemist in a former life and have a perspective from another angle, which might help.

I know that all the answers above are absolutely correct which doesn't really give you something definitive, per se. I think you need to rephrase your question and first put it to the Sail Designers who work with the material suppliers intimately (even in China). A lot of research goes into a product before its release and during it market life. That's how I made my living, for a period in my life.

There can be inferior materials used as sail cloth, due to either, a. Poor material choice, and/or b. Poorly manufactred materials (bad production quality)Dacron is only one of many materials on the market. As far as UV resistance; additives (UV inhibitors) are included in the production of polymers. How much depends on what the developer wants to achieve on the overall stability of the end product, too much or not enough will affect a materials stability and longevity. There is a trade off.

So, I might suggest you pose the question to North Sails, et al, and ask what does the aging research show for the materials currently on the market. How does Kevlar rate compared to Dacron? What is the stitching material and what does the research show for it? (good chain/link observation from another replyer).

Once you have the reseach in front of you, then pose the question to the sailers using specific materials under the various conditions. (side note: I've seen alot of uncovered sails lashed to a mast for some time. Lazy sailers who don't cover ASAP ultimately pay for thier neglect. I love the furled engineering. Just smart, all the way around.)

Good Luck
Sailcat

[nickjaxe]

G'Day Jim, as far as I know its Dacron for the larger panals with some other material elsewhere on the wing....the main problem people are having is with the dacron with stiching being more or less ok....it is tested along with the wing material and some does fail,

The wing material is tested with a device that attempts to rip the fabric under a predetermined tension, its a spring balance with a spike in one end to anchor it to the fabric,

The wings are failing at between 200 and 400 flying hours with probobly 2-3 hours per flying hour spent just parked up,

Normally the aircraft are hangered when not in use,

Its a recent problem with wings that where made in the last 3/4 years being effected....older ones seem to last much longer,

As far as we know the wing fabric is the same as sail boat fabric.

Nick.

[Jim Cate]

Originally Posted by nickjaxe

G'Day Jim, as far as I know its Dacron for the larger panals with some other material elsewhere on the wing....the main problem people are having is with the dacron with stiching being more or less ok....it is tested along with the wing material and some does fail,

The wing material is tested with a device that attempts to rip the fabric under a predetermined tension, its a spring balance with a spike in one end to anchor it to the fabric,

The wings are failing at between 200 and 400 flying hours with probobly 2-3 hours per flying hour spent just parked up,

Normally the aircraft are hangered when not in use,

Its a recent problem with wings that where made in the last 3/4 years being effected....older ones seem to last much longer,

As far as we know the wing fabric is the same as sail boat fabric.

Nick.

Wow, Nick, that seems pretty grim! As others have said, sailcloth comes in a huge variety of weights, finishes, materials and yes, colors.

I suspect that your wings are covered with a very lightweight material, weight being so critical in flying. In our sails, most lightweight sails (spinnakers, drifters, etc) are made from Nylon, typically in 3/4 oz to 1 1/2 oz weights. The lightest Dacron materials are >2 oz, and most normal sails are made from ~5 oz up to 10+ oz weights for storm sails.

So, it may well be that while the base yarns used in your wing covers are the same as sails, perhaps the weaving and/or calendering of the cloth is different, and that the UV inhibitors vary as well.

Whatever the cause, failure after ~600 hours of sun exposure is really poor performance.

Oh, BTW, do these wings have both top and bottom covers, or do they consist of a single layer of cloth like a sail? If they are covered on the bottom of the foil, does the bottom layer fail as quickly? The bottom would receive less UV exposure...

Cheers,

Jim