Experiences With Dacron/Mylar Laminate Sail Cloth?

[rardiH36]

Any "real-use" experiences with Dacron/Mylar (or "flexible mylar taffeta") sail cloth?

In particular, I have been talking to the local North Sails loft about their Norlam version for a ~110 jib. Yes, I have finally decided to go new this time rather than pre-owned! But only in respect of a more performance oriented cloth that can hold it's shape over the years. For Dacron, I figure if I buy new it will lose a lot of shape after just a few years sailing in "the slot's" +20kt typical wind. So if Dacron, might as well go used.

North claims that Norlam will hold it's shape much better than even the best dacrons. And that it does have a history of many years durability (up to 20) for cruising applications. I am willing to sacrifice a few years less duration compared to dacron for better performance. But not to the extent of racing fabrics which perform great for a several years then begin to break apart as the fibers/mylar fray and crack... as is the case with my existing pre-owned kevlar racing jib which I can no longer spot repair. Too far gone.

I have read that mold can be a problem with the dacron/mylar cloth? Other than that I haven't encountered any real world reviews on the internet.

Thanks for any insights.

 

[Jackdaw]

Norlam is simply a double Dacron taffeta over straight Mylar film. The big difference between this and double taf racing sails is the lack of directional fibers as load path re-enforcement. The good news is Mylar is VERY strong when resisting stretch on its own.

Good sails for their intended purpose.

 

[CarlN]

Ask North to give you some "20 year" Norlam sail references to talk to. (Or even 10 years)

My personal experience with cruising laminate sails is less than five years (not North but another big name). I've gone back to top end woven dacron which is now hard to find. I use Mack.

http://www.macksails.com/sailclth.htm

 

[rardiH36]

Carlf:

Very useful info and thanks for link to Mack's sail cloth page. I need to give this more thought!

 

[John Nantz]

Go with heavier cloth

Not much time to write this so here goes...

NorLam: The sail I have was a new North NorLam 150 tri-radial. Lasted just a few years until it lost it's shape. The wind range I was quoted was much higher than what should have been but I didn't find that out until afterward. Now the North loft says it's not worth a re-cut. Grrrr....

Since then I've gone with a new North dacron main and jib, both cross-cut. For both sails I went to the next heavier weight cloth than what their tables would have recommended. The good part is the mainsail has held up perfectly. Full-batten main - since then the move has been to only full battens on the uppers but mine has all full battens. The main is absolutely great - and it's about 18 years old. The bolt rope may have shrunk but it if has it's hard to tell.

The 110% furling jib was designed with a foam luff for reefing - I wouldn't recommend that again. With the heavier weight and a slightly flatter cut for the Bay I'd leave it at that. Better shape and the flatter cut for a tighter sheeting angle. We have a fractional rig so with your masthead (I think that's what you've got), as they say, your mileage may vary.

We take our sails off in the fall for the off season to try and avoid mildew.

Better slugs on the main for easier sliding might be nice.

Oh, and we retained the Dutchman system. I don't race so this is nice to keep everything gathered up and not sliding around all over the coachroof. Ours is closer to a one-man boat than it used to be.

 

[Ken Cross]

I have no idea how old it was, but ours (Gen 130) on our old San Juan 28 (masthead rig) delaminated after I had used it 5 years.

Ken

 

[rardiH36]

John/Ken/Carlf:

Many thanks for your responses. Your info reinforces my own doubts (which is why I posted the question) about North's advice of the excellent performance/durability/longevity of dacron/mylar/dacron sail cloth. This type of sail cloth type has been around for many years. But I couldn't find info that it is acknowledged to be the best compromise of long term performance and long term durability.

I will check with Mack Sails (and others) instead about the highest grades of Dacron. Such as "Marblehead". Seems that after a few years and some stretching of the cloth, sails constructed of these Dacrons can be re-cut to restore much of their original performance. And I would think that after the initial stretch, maybe the sail will thereafter retain good performance for even longer?

Also from my reading, a radial sail has better initial shape and performance. But also that after a few years, a cross-cut sail is much easier/cheaper to re-cut towards original performance than a tri-radial can be?

If so, then the best "equation" for me will be lowest stretch highest quality Dacron and cross-cut construction?

 

[rardiH36]

Not much time to write this so here goes...

The 110% furling jib was designed with a foam luff for reefing - I wouldn't recommend that again. With the heavier weight and a slightly flatter cut for the Bay I'd leave it at that. Better shape and the flatter cut for a tighter sheeting angle.

John:

I also wondered (briefly) if a new sail could be cut a bit flatter if used in windy environments. Thanks for reinforcing the thought and I will ask the opinion of whatever loft I eventually go for. In San Francisco Bay, I want the best close-haul performance for the almost every time out beat against the wind and current. I am will to sacrifice off wind. And much of the time, the wind is so strong that when not on a reach, hull speed is acheived when off wind irrespective of the condition of the sails.

Several years ago, I did experiment with luff build-up for better shape when roller reefed. Particularly, I had read that instead of foam, North (I believe it was them) instead sewed light weight polypropylene rope along the luff. This resisted mildew/mold better than foam. I DIY'd the same to an older but serviceable jib of mine. Yes, for the first couple of wraps around the furler, the shape was a better. But when I absolutely need to reef the jib, usually the winds are real strong so 50%- 75% of the sail out is the norm. The rope augmented jib with that many wraps still had bad shape. So you are probably right >> Flatter cut and no foam on the luff. Also, when I recently spoke to Hood Sails, although the local manager mentioned foam luff as an option, he let go of the idea immediately when I opined probably not. Anyway for my boat, it performs best for "normal" high winds (25-30kts) on the second mainsail reef and the 110 jib flying full. Not a full main and a reefed jib as some boats do better with.

regards,
rardi

 

[rardiH36]

Not much time to write this so here goes...

The 110% furling jib was designed with a foam luff for reefing - I wouldn't recommend that again. With the heavier weight and a slightly flatter cut for the Bay I'd leave it at that. Better shape and the flatter cut for a tighter sheeting angle.

John:

I also wondered (briefly) if a new sail could be cut a bit flatter if used in windy environments. Thanks for reinforcing the thought and I will ask the opinion of whatever loft I eventually go for. In San Francisco Bay, I want the best close-haul performance for the almost every time out beat against the wind and current. I am will to sacrifice off wind. And much of the time, the wind is so strong that when not on a reach, hull speed is acheived when off wind irrespective of the condition of the sails.

Several years ago, I did experiment with luff build-up for better shape when roller reefed. Particularly, I had read that instead of foam, North (I believe it was them) instead sewed light weight polypropylene rope along the luff. This resisted mildew/mold better than foam. I DIY'd the same to an older but serviceable jib of mine. Yes, for the first couple of wraps around the furler, the shape was better than without the rope buildup on the luff. But when I absolutely need to reef the jib, usually the winds are real strong so 50%- 75% of the sail out is the norm. The rope augmented jib with that many wraps still had bad shape. So you are probably right >> Flatter cut and no foam on the luff. Also, when I recently spoke to Hood Sails, although the local manager mentioned foam luff as an option, he let go of the idea immediately when I opined probably not. Anyway for my boat, it performs best for "normal" high winds (25-30kts) on the second mainsail reef and the 110 jib flying full. Not a full main and a reefed jib as some boats do better with.

regards,
rardi