Radial or Triradial Headsail

[dlochner]

by going to the smaller headsail you will be opening up the slot between the sails and will improve the performance of your main. giving you some of the bump your looking for back.

The goals are to have an easier to handle headsail with a minimal sacrifice in speed and performance. Compared to a dacron 150 I expect to see little to no difference in the 12-18 knot range, improved performance in 18-22 as I won't need to furl the headsail as soon, some loss in performance in the 8-12 range, and for winds under 8 I have this big hunk of metal that works just fine for getting somewhere in a hurry. Out of the bag, there is probably little difference between a good crosscut dacron and a radial cut sail, it is down the road a few years where it will make a bigger difference. That's why I'm willing to pay extra to get a radial cut sail.

dupont quit making dacron many years ago. i like the term 'dacron family'. there is no real dacron any more as i understand it.

Dacron was a Dupont brand name for polyester yarn. Like "Kleenex" it lost its brand name status and became a generic word for polyester. Same with Kevlar, its a brand name for aramid fibers. I believe that Dupont got out of the polyester fiber business a few years ago.

There are cruising laminates available that feature external taffeta made out of, I'll call it "dacron family" material.

Both lofts I'm talking to spec'd this cloth: CDX Polyester Cruising Laminates - Contender The cloth has polyester taffeta layer, mylar film, 2 layers of polyester yarns, and a polyester taffeta. For a sailor who wants performance but isn't interested in racing or has a more limited budget, this seems to fit the bill.

I haven't found a reference to monofilm sails for bigger boats, but sailboards and some small, high performance catamarans and hydrofoils are using molded sails.

North has been building molded sails for a while now. The current version is CDi and just replaced the Cdl line. All the sails on the current iteration of the VOR are North CDis. They expect the mainsails to last the entire race. The technology is proven and would be a choice if my pockets were much deeper. Paying for state of the art technology and marketing budgets puts North sails out of my range.

My new headsail is the DP Lite Skin in that link you referred. The Lite Skin is a laminated blend of CF and polyester.

If I was racing, this would be high on the list of fabrics I'd want. ‎www.dimension-polyant.com/en/pdf/DP_Carbon_Sport_E.pdf It is designed for club racers, I don't need that level of performance. It would be nice but I can't justify the expense given my sailing habits.

Thanks to every one for the comments. I'll be making a decision over the next week or so.

 

[DrJudyB]

dupont quit making dacron many years ago. i like the term 'dacron family'. there is no real dacron any more as i understand it.

dupont quit making dacron many years ago. i like the term 'dacron family'. there is no real dacron any more as i understand it.

Dacron is the trademark of Dupont. It refers to polyester. Taffeta is a thin skin of woven polyester yarns that is laminated to one or two sides of a film-scrim-film laminate "sandwich". The Tafetta skin provides abrasion resistance and some UV resistance when it's glue to the outside of the film-scrim-film laminate.

The scrim is the load-bearing component, not the dacron or the film.

My new headsail is the DP Lite Skin in that link you referred. The Lite Skin cover layer is a laminated blend of CF and polyester, with a CF scrim in the center.

I'd like to make a minor correction or clarification to Larry's comment. When he refers to CF (carbon fiber), he is talking about to the underlying laminate, not the Lite Skin. Dimension Polyant puts a Liteskin (TM) outer layer on two different laminates.

Liteskin is the trademark name for a sheet of random array, non-woven filaments invented by Dimension-Polyant. It's kind of like felt. It is non-load bearing. It is used as an abrasion and UV resistant skin on one side of the underlying laminate. It is lighter weight (sort of), more UV resistant, and absorbs less water than taffetta. It is compatible with glued seams; tafetta is incompatible with glue. LiteSkin looks cool too, with a smooth, sleek gray finish.

At the present time, DP is offering LiteSkin as an option on one side of two different laminates - Carbon Sport and GPL-GraphX. Carbon Sport is a laminate using scrims of carbon, twaron, and polyester. GPL-GraphX has carbon and twaron scrims, without any polyester. GPL-GraphX is more expensive and engineered for larger boats. Carbon Sport is targeted at club racers and small to medium sized boats. Carbon Sport is less expensive than GPL-GraphX.

Carbon Sport and GPL GraphX are also available without LiteSkin, at a considerably lower cost for pure racing use.

Other companies, like Contender and Doyle and UK, sell carbon and twaron/aramid laminates with and without taffeta skins.

At present, I believe UK and perhaps other manufacturers have a license to use use LiteSkin(TM) on their products.

At a significantly lower price point, traditional cruising laminates with load bearing polyester scrims and tafetta skins on both sides are still avabilable from Contender and Dimension-Polyant. They are used for tri-radial sails, which generally resist stretch better and traditional cross cut sails of woven polyester (dacron). They are a good value. They last a very long time without delaminating.

 

[Captain Larry-DH]

Thanks for the correction, Dr Judy. I was under the impression that the Lite Skin contained carbon fibers mixed with the polyester in a non-woven laminate, and yes I understood the skin was non-loadbearing.

 

[Bosman]

Excellent summary DrJudyB - very detailed and informative.

 

[jon hansen]

thanks doc. enjoyed the read.

and learned

 

[Jackdaw]

DrJudy’s posts are right up there with Maine Sail's. Accurate and full of great, professional information. I read them twice.

 

[dlochner]

Wanted to follow up on this thread and thank everyone for their comments.

In the end, I decided to go with a 135% trip-radial headsail made from Contender CDX laminate. CDX Polyester Cruising Laminates - Contender This cloth is constructed as DrJudy described, taffeta, mylar, polyester scrims, and taffeta. Both lofts recommended the same cloth.

As I did more research on the headsail design, it appears that a bi-radial sail is a better design for racing and going hard to weather. The load paths align better with windward sailing than when reaching or running. A trip-radial sacrifices a little when going to weather, however, the load paths align better when reaching or running. Since gentlemen don't sail to weather, the tri-radial made more sense for my sailing.

 

[FastOlson]

One quibble about the phrase "better for racing".... Racing is what you do when you are entered in a race. It's all just sailing -- good sail shape is good no matter why you are out sailing.
If you happen to look at our picture of our boat with it's 95% jib with three vertical patterns, note that it has a fuller shape aloft and gives us "about" the upper drive of a 110%. We really like the battens. As for material and layup, fun to study and learn about, but the sailmaker knows this constantly-changing stuff and I rely on his experience. Our jib is laminated out of low stretch unobtanium and some other materials...
Works great, and no doubt it's 2012 technology has been superceded now by other materials...

Click on my Albums page here for a larger picture of it.
Fair winds!

 

[dlochner]

One quibble about the phrase "better for racing".... Racing is what you do when you are entered in a race. It's all just sailing -- good sail shape is good no matter why you are out sailing.

The reason I said "better for racing" is that racers typically sail windward and leeward legs. Going to weather the load paths on the headsail are primarily along the leach. As the sail is eased in a reach or run, the load paths change with increased loads emanating from the tack and loads along the leach decrease.

Since the vast majority of my sailing is on a reach to broad reach, it made sense to get a sail that was designed for these load paths. In theory, this should give the sail a longer life in my use than a sail that is optimized for sailing closer to the wind.

Sail choices are compromises, especially with a more limited budget. Not all of us can buy a new sail a year or have a deep sail inventory. My choice was for a general purpose sail that would hold its shape well and have better performance and life than a crosscut polyester sail, especially as I was down sizing the sail to accommodate higher winds and easier handling.

 

[jssailem]

unobtanium

Really?
un·ob·tain·i·um a highly desirable material that is hypothetical, scientifically impossible, extremely rare, costly, or fictional, or has some of these properties in combination.