X-ply vs monofilm

[antonputman]

I am looking to buy a used sail and set my mind on a North Volt 4.7 from 2013. There is one particular offer in the HD version, which means X-ply instead of monofilm.
"VOLT HD Ultimate durability for brutal conditions: The new LDO is also available as a monofilm-free hardcore X.PLY version!"
I am trying to understand the difference between the monofilm version.

- Is it true that X-ply has a lifespan 2 or 3 times greater than monofilm?
- What about weight? On North's website I see in the spec sheet only a difference of 5 grams, but that sounds impossible
http://www.north-windsurf.com/eng/nodes/display/product/2013-volt-volt-hd
- What about visibility? Looking trough the panel chasing waves.
- Any other differences? Is the sail maybe stiffer? I just bought a used 100% carbon 400 mast but in SDM version with North's DROP.SHAPE geometry, will this work ok?

Attached a photo of the sail.

[thombiz]

Hi, I'm Bob T from Corpus Christi. I'm the local sail repair guy and I have some experience based opinions about monofilm and x-scrim which may help you. I've been repairing sails since 1997 and have repaired about 8000 sails. The topic of UV exposure to monofilm & x-scrim has been one of interest to me. Back in 2003 I was trying to determine the effectiveness of 303 UV Protectant so I put samples of monofilm, fabric, and x-scrim in the back yard to expose them to UV. I covered a portion of each sample with 303. You can read the whole write-up here: https://groups.google.com/forum/#!searchin/rec.windsurfing/303/rec.windsurfing/bKEmF4vTiUM/FI2uuy-DRbQJ

I still stand by the results from those tests. Be forwarned, there are manufactures who use x-scrim to give their sails credibility, but in my experience, their x-scrim has been very problematic due to the below par materials used to make the x-scrim. Typically, they use a 2 or 2.5 mil monofilm on one side of the x-scrim and a .5 or 1.0 mil film on the other side. It looks all nice and x-scrim'y when new, but ......the .5 mil monofilm lasts about 1/5th of the UV exposure of the 2.5 mil. which causes premature failure of the panel.

Over the years, my opinion that x-scrim has an effective life span at least 2-3 times longer than monofilm has only been reinforced by what I see in the repairs I make day after day. When purchasing a sail, I definitely look for sails with the most x-scrim from the best sailcloth manufacturers.

When it comes to wave sailing and being able to look thru the panel to see the wave in front of you.....it's personal choice. It probably is a good thing when a sail is very new, but after a couple years use, looking thru monofilm or x-scrim is not that easy.

Now to North. I've made hundreds of repairs to North sails. A few years back, they made some of the very best products on the planet. My experience over the past 5 years has changed my opinion of them. When I purchase sails for my own use, I've found there are many many brands with build quality I prefer, like Goya, Ezzy, Simmer, Sailworks, Windwing, Hot Sails Maui, Naish, and Northwave. Over the years, these are the only brands which have earned my respect thru their durability and construction details. I have friends who would like to see me sailing Norths, but then I've repaired quite a few and they don't make my cut by a long shot.

[isobars]

It's pretty simple for me. A tiny tear in monofilm often produce a complete blowout, but in X-ply it almost always remains just that: a tiny tear. Would you rather swim an exploded monofilm sail to shore in that surf, pack up, and go find a repair shop, or would you prefer instead to ignore a small tear until lunch, slap some clear tape on it permanently, and keep sailing? No guarantees, but those are the more likely scenarios.

It's also been postulated that the raised grid of X-ply helps protect the clear segments within the grid from abrasion, especially during rigging and while rolled up. Makes sense.

I replace my sails that have X-ply windows annually (the annual depreciation cost is roughly equivalent to longer rollover periods and I get crystal clear windows to boot), but may keep the sails with PVC windows for much longer, partly because PVC can be made to look (and see through) like new in minutes with a bit of elbow grease and plastic polish. PVC is too stretchy for ordinary-sized sails, though; I reserve it for my 3.2 and 3.7.

[dsgrntlxmply]

I sail Ice HD in 4.5, 5.0, and 5.7, plain Ice in 5.3, plain Volt 6.4, and Natural 7.3 and 5.8 (the 5.8 is seldom-used).

I feel that the HD construction has been very worthwhile (both by cost and weight) for panel durability, and I wish that I'd been able to get the Volt 6.4 in HD. The distributor was said to have chosen not to bring in the Volt HD (or perhaps not at the time that I bought the sail). I have yet to suffer a significant rip in any of the Ice HD sails.

The Natural 7.3 has suffered a couple of rips, and a small rip in the monofilm will become a large one very quickly. I'd say that Natural is built more to a weight and cost objective than for durability. I am happy with the lower weight for that larger sail, and the price was agreeable.

The weak point on North Ice has been the battens: far too easy to break. It looks like Volt and other newer North sails have gone to a different batten design, and I hope that it will be more durable than what they used in Ice.

[boardsurfr]

We bought 4 used Gaastra Manic sails a few years back - 2 were HD (4.5 & 5.3), two monofilm (5.0 & 5.7). The first sail to fall apart was an HD. We repaired it once, but it the next panel failed a short while later, with huge rips through the X-ply after minor crashes.

The other sails also started failing within a few months. There was some correlation between how often we had used them, but monofilm vs. HD did not seem to make a difference. The HD sails definitely did not last 2x longer than the others. The sails were about 7 years old when they started disintegrating. We have had them for about half of that time, and used them frequently (up to more than 100 times a year).

Just a bit of anecdotal evidence that x-ply does not always last longer. Maybe these sails used the poorer-quality x-ply that thombiz mentioned. But we probably got at least as many sessions out of these sails as we got from NP or older North sails before those started falling apart.

[isobars]

IIRC, the monofilm material, regardless of whether it has reinforcement, survives about 200 hours of sunlight before it begins falling apart. At 7 years X 100 "times" per year, you were playing rugby on pudding skin, not skating on thin ice.

[boardsurfr]

Your numbers are a bit wrong. I stated that we owned the sails about half of the time, so it's closer to 3 years x 100 uses for the most heavily used sail. The average session was probably 2 hours. Still, that gives you a lot more than 200 hours. As tombiz pointed out, material thickness is one important factor. These were rather solidly built wave sails.

[leto]

Totally with the thombis on the North sails; have exactly the same opinion. Things went sour after they stopped making Voodoos. I stopped buying North 5 years ago and very happy with Naish and Severnes.

North construction is crap, almost all monofilm. Some sails are quite heavy and using older style x-ply material which is durable but very heavy. Plus I guess I'm lazy and got tired of them changing sail names every year..

Their masts are still OK though. Probably booms too.

[antonputman]

Just to follow up on my question.

I was so convinced with Bob's recommendations that I bought two used 2009 Ezzy Panther's in 4.7 and 5.5 for peanuts really. I wanted the 4.7 only but when my seller rigged it to show me I instantly got his 5.5 as well.
Amazing how much shape the 5 year old sails still have! You can just smell the craftsmanship and durability. The materials feel top notch, and completely monofilm free. I was surprised to learn about the PVC / vinyl window.
Both variotops too. For the 4.7 I'll have the recommended 400 mast, a North Platinium in SDM, drop shape. Looks perfect. For the 5.5 I can use the second choice recommendation with my 460 North Silver in SDM. It looks good too.

Unfortunately because of lack of higher wind I did not try the sails out but I have a feeling I will become an Ezzy fan. I have been reading a bit on their website and like the story and filosophy. Also their mix and match mast concept. I am getting pissed to see that about every sailmaker makes sails where every 2 sail sizes seem to need their specific mast. WTF? That was one of the main reasons I choose North to begin with, the other mainly because I am a professional yachtsman sailor and North is/was the only choice to win. I even worked in a North loft (yachts) for more than a year.

Anyway I am looking forward to try out the Panthers! I am just getting into small wave sailing so the investment to learn into waves is very small.
If I like the sails I think I will get some Tigers next season.
Never take some brand for granted!

[isobars]