The point is, Wouter claims that there are broadseams in a 3DL sail, this is false. Wouter even threatened to go directly to North Sails and ask them if broadseams are used in a 3DL sail... So, has he asked them as he claimed he would do? and if so what is the answer?


Now after enduring numerous attacks over my credibility I am taking issue with the matter and have asked Wouter more than 3 time to either:-

1. Prove his claims, show me to be a liar and I will never return to the F16 forum. (now that would make a few of you happy, so whats the holdup? you now have a way to make me go away)

2. Admit he is wrong and apologise for attacking me. (and I am not looking for an apology along the lines of his previous "truce" offering...)

Found the following links describing the patent that 3DL falls under, and comparing the methods used by North compared to other sail manufacturers.

Full details are on this link (won't copy the text as it is one of the few things that are longer than Wouter's posts):

http://www.patentstorm.us/patents/6382120-description.html

http://www.patentstorm.us/patents/6311633-description.html

But there is also this definition:
1. Sailmakers may shape, i.e., broad seam, the novel panels in the traditional manner. For added benefit, a selvage may be provided in the weaving process to also allow sewing (besides the increasingly prevalent gluing of seams).


For me, that definition is not necessarily true for 3DL. The shape of the sail is contrived from the mold and from laying of the yarn or fibres. The mylar film is only used to hold this in place. If they could, North would make this film the size of the whole sail as it would be lighter and produces less weak points, but that isn't conceivable or viable.

I know that Quantum up the road in Malaysia use broad seaming but the sails are made "3DL style". They have carbon and kevlar-fibre sections held together with mylar film, but the panels are about 1.5m to 2m wide and glued together. This way they get around the 3DL patent.

Macca made a Finn reference in an earlier post. That class requires broad-seaming. North get around this by essentially making a 3DL sail, then chopping it into panels, then gluing it back together to make broad seams.

Hope this helps.

Just to add, my view is that broad seaming can be asked in the following way:

"Is the shape of the sail being made by the gluing/sewing of the panels?"

3DL would be no, but other sails would be yes.

Whether my question is correct or not, I am not sure. But that is the way I see it.

Though as suggested in my earlier question, it seems that "being made by" may mean slightly different things to different people.

How about those of you who don't believe me go and have a look at a 3DL sail, take a photo of the broadseam and post it here?

I left my question open to interpretation and it is down to the measurer to make the final call. I am sure that there is an ISAF guideline, or documented evidence from an ISAF recognised class outlining what is acceptable and what isn't. Maybe able to find time later to google.

Personally I wouldn't know a 3DL sail if I fell over it, but are we right to understand that you're saying a 3DL has no "seam with a sail shaping purpose"?

If this is the case, how would a photo tell you the purpose of a seam?

I ask the question because if you go and have a look at a 3DL sail you will spend a long time looking for a seam of any type.... there are none <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Now, As I am an unemployed bum this week (wayne would contend that I am unemployable..) I have time to dig up plenty of info. From the 2007 Finn class rules:-
.pdf]http://www.sailing.org/tools/documents/FIN2007_CR_240307-[469].pdf

Rule G.1.7 (b) continuous layers or fibres crossing the seams are prohibited.

So if a 3DL sail had seams it would be class legal in the finn without the current process of cutting the sail and regluing it to make the seams.

They plot,cut then glue the mylar panels together then they lay the mylar sail on to the mold then they lay the carbon strands over the mylar while doing this they are heating the sail and the glue so the cloth and strands take the shape of the mold. it's a bit like heat shrink. You can sew the mylar panels together but the glue is stronger than the cloth. These are crosscut sails with glued yarns. I havew a picture of the Maxi yacht Wild Oats 11 in a mag and you can clearly see that it is a crosscut sail with load path yarns. Have a look at the Genoa where the battens are the are seams.

http://nsweb.itinfo.dk/UK/3DL_Technology.asp

Vid on this page shows the process. Shows the differences between the more traditional broad-seaming style, to the very tech 3DL style.

Seen many of these sails as I am usually in adventureland (ie bowman) when yachtracing. Massively lighter than a panelled sail which is great. But once the sail is made, limited re-cutting available. Generally only the luff curve can be changed.

Ummm NO. what you think are seams at the batten pocket are in fact extra fibres running from the front edge of the batten pocket to the luff of the sail. These were introduced in 2007 accross th 3DL range for GP spec sails. basically it improves the longevity of the sail with minimal weight gain. essentially it acts like a longer batten than is actually there. A bit like a full battened jib without the handling issues of a 38ft long batten <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

So presumably the seams in the mylar disappear under heat & pressure?

In section 4 of how 3dl sails are made it said that the mylar film is joined at seams do these just disappear? or can they still be seen while sail is flying.


4. After a base layer of Mylar film (made from Mylar sections joined together with modest shaping to lie reasonably smoothly over the 3D surface of the mold) is draped over the mold and tensioned, a 6-axis fiber head suspended from a computer controlled overhead gantry then applies structural yarn onto the surface of the base film, precisely following the 3D curve of the mold surface. The fiber head "draws" a pattern in yarn that matches anticipated loads in the sail. All structural yarns are applied under uniform tension and adhere to the surface of the film to ensure they remain in place prior to being locked by the lamination.

They are really hard to see and you have to look closely. Not what you really would call seams. The mylar film is quite thin, and as I mentioned in an earlier post, the film is in sections as it wouldn't be viable to make the whole sail as a single film (but I am sure that Norths are looking into this). The seams are essentially just a way to join the whole sail together, but wouldn't meet the definition of broad seaming in creating shape, as opposed to holding the shape made by the kevlar/carbon yarns.

Where is Wouter? MIA?

Sorry Rolf,

Macca is corect from his figures based on the last time myself and some others discussed this the the Secutary Genral of the International F18 class. I am sure he has a lot more insite into what is happening within the F18 class globaly.

Macca may also have insight into real build numbers from one manufacture atleat.

Wouter, Wouter, Wherefore art thou?

Give us the answer we have been searching for.

This is the most hi-res pictures i could find on the Internet,
its a genoa from an +/-35 ft sloop:
http://www.frers.nl/wp-content/uploads/2006/12/dsc00425.JPG

I simply never expected you would go a low as telling a bolt lie in a public forum.

I guess that everyday you learn something new.

And just to be clear, I am calling Andrew McPherson a dirty liar now !

Wouter

Wouter,

How about you go back and edit your post so it makes some sense.

While you are at it, either get the proof or apologise.