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Mar 03, 2018, 06:29 PM
Beach Bum
SteveMongr's Avatar

C-rig


DF65 C-rig 35 - 45 knots Cape hatteras (1 min 5 sec)
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Mar 04, 2018, 04:31 AM
Beach Bum
SteveMongr's Avatar
I found someone to make a D- storm sail. This person makes A+ sails for the 65 and full sail sets for the DF95. The C-sail works very well under 30 knots but it blows 30+ almost every week. When i sail into the full force of these winds the hull will often disappear underwater when turning downwind. Snapped the sheet to main sail as well, guess 30lb test is not enough. Good news is that boat was dry inside.
Using Li-Fe battery 700mah in battery tray (weighs half that of AA and can sail multiple times on one charge). I extended charge lead to reach out the smaller
access hole. I would prefer ripstop sails over mylar, it does not crease as easy and is not as noisy.
https://www.ebay.com/itm/13252165431...m=132521654310
https://www.rocksails.com/
DragonFlite65 35-40 Knots (1 min 41 sec)
Mar 04, 2018, 09:12 AM
"consumerwil"
denisoni1's Avatar
... I was wondering how you found a set of D sails .... those as actually - A+, A, B, C - So the one you are sailing is a "C" Sail set... Rocksails (Jann) are nicely made sails


Quote:
Originally Posted by SteveMongr
I found someone to make a D- storm sail. This person makes A+ sails for the 65 and full sail sets for the DF95. The C-sail works very well under 30 knots but it blows 30+ almost every week. When i sail into the full force of these winds the hull will often disappear underwater when turning downwind. Snapped the sheet to main sail as well, guess 30lb test is not enough. Good news is that boat was dry inside.
Using Li-Fe battery 700mah in battery tray (weighs half that of AA and can sail multiple times on one charge). I extended charge lead to reach out the smaller
access hole. I would prefer ripstop sails over mylar, it does not crease as easy and is not as noisy.
https://www.ebay.com/itm/13252165431...m=132521654310
https://www.rocksails.com/
https://www.youtube.com/watch?v=4jqtqLg7S2g
Mar 04, 2018, 09:51 AM
Beach Bum
SteveMongr's Avatar
Quote:
Originally Posted by denisoni1
... I was wondering how you found a set of D sails .... those as actually - A+, A, B, C - So the one you are sailing is a "C" Sail set... Rocksails (Jann) are nicely made sails
Yes, the videos I posted are with C-sail from Josway. The D will be custom made by Rocksails.
35+ knots DragonForce65 C-sail (1 min 25 sec)
Last edited by SteveMongr; Mar 05, 2018 at 04:53 AM.
Mar 10, 2018, 09:49 AM
Registered User

Legal Sail Matrial


I am considering making sails out out completely flat, super light weight laminated Dyneema rip-stop cloth mostly used for mountaineering applications. Lay it out on a table and it is 100% flat. Being Dyneema there simply is no stretch. That is why I want to try it and Hot sails has experimented with this fabric. In your opinion, is this a legal fabric?

Are laminated sails even legal? Are Trispi sails legal? According to Merrium Westers Definition for Ply is as follows:

1 a : one of several layers (as of cloth) usually sewn or laminated together
b : one of the strands in a yarn
c : one of the veneer sheets forming plywood
d : a layer of a paper or cardboard

Our rules read "Construction shall be a soft sail of a single ply. The Jib and Mainsail of any given rig size shall be
constructed from the same ply.
All sails shall be constructed of a single panel with no seams and the maker shall not try to
introduce camber (shape) into the sail by means of heat or force. "

Trispi sail cloth is made up of three plies. A scrim sheet, the woven fibers, then a second scrim sheet. That is a total of three plies as defined by Websters. According to Dana Paterson If a layered of fabric (laminated with heat-activated adhesive in between the plies) is stretched and relaxed it will have a belly that pops back and forth like the bottom of an old-school oil can. THAT would be an illegal 3D sail.

Should our class rules read more like Construction shall be a soft sail of a single ply. "The Jib and Mainsail of any given rig size shall be
constructed from the same weight and type sail cloth."
Or
"Sail material shall be a "Mylar" polyester film constructed from the same weight..."
Mar 10, 2018, 06:46 PM
Registered User
An interesting point. The 2017 1.6.1 rules do indeed say "a soft sail of a single ply" and that would seem to rule out any laminated cloth like Trispi or Mylar Sail Cloth (dacron or nylon sandwiched between Mylar films) and the cloth you propose to use for DF65 One Design use. It would seems that for Mylar, only single Mylar film can be used.

Those cloths are (probably) legal for RG65 use. I haven't check but I think only sail area is limited.

Looking around Soch sails appears to use straight mylar for their DF65 sails at least as far as can tell...
https://sochsails.co.uk/df65-sails-mylar-film/

but other makers have other choices... eg
https://www.siriussails.com/dragonforce-65.html

My guess is that only the three plain Mylar options are class legal assuming they are straight Mylar and not laminated sail cloth. But sirius seem to recommend Trispi. Perhaps they missed that part of the rule or perhaps there is some other interpretation of "a single ply" that is not obvious?

I think a rule clarification is required as to what it means by "a single ply" and why that rule exists.

The rules certainly should not say that the sails should be "Mylar" because the stock sails prior to Verion 6 were ripstop nylon. The sail construction rule is intended to make it reasonable for a owner to make their own sail and so deliberately does not specify material or source as doing so invites obsolescence and artificial pricing. A particular material may become hard to get for whatever reason.
Mar 13, 2018, 04:22 PM
Landlocked Sailing Addict

Legal Sail Material


Hi All

As I see it, the intent of the rule is that no expensive laminated cloths are used and that the sails themselves remain single surface - in the spirit of keeping the costs down, facilitating home made sails and maintaining a level playing field.

I guess the devil is in the details, but for me a layer of cloth is a single discrete sheet that cannot be separated visually. I consider Trispi to be a single layer cloth because the mylar film has been bonded in such a way that it is effectively welded into a single layer. The scrim reinforcement is not a layer in itself - it's part of the cloth structure.

If you were to consider Trispi to be a non-single ply cloth, for the sake of consistency, you would have to consider any modern woven sail cloth to be non-single ply. Icarex consists of a warp and a weft and is coated on both sides (that could be held to be four layers using this approach).

Both Sirius and Cat Sails offer DF 65 sails cut in scrim mylar (Trispi). Cat Sails are highly experienced and I doubt they would manufacture a sail that was illegal. I cut my own sails (for my DF 95). I've used both standard mylar film and Trispi.

My personal experience is that there is no performance difference between Trispi sails and standard Mylar film sails. If anything, the Trispi sails might have a slight disadvantage because the surface is a little uneven. The only advantage I see is that Trispi doesn't tend to crease as easily as Mylar film - so there is a longevity and durability benefit. Trispi's stretch characteristics are pretty much the same as Mylar film - I've got identical sails out of each cloth and find that I'm using identical tuning settings regardless of which cloth sail I've rigged.

You can get any flat cut sail to belly out - that's part of the art of boat tuning. It's easier to do with shaped (panelled) sails because you can optimise the shape at various parts of the sail - so there's a performance advantage there. However shaped sails are harder to build (= more expensive if done professionally) and less durable (seams will eventually move). Therefore such sails (in keeping with the spirit of the DF classes) are ruled out.

In fact, under the DF class rules, the only thing you can vary is the luff round on the mainsail (and then it still has to conform with the girth measurements). Everything else is pretty much fixed with very exacting tolerances.

I'm happy that, whatever cloth people choose for their sails (Mylar/polyester film, Trispi, Icarex etc.), the DF rules are such that no-one is getting an overall performance advantage based on cloth choice. There are more performance advantages to be had in setting up your rig right, then sailing the boat properly.

My kind of model yacht sailing..........

Cheers!

Karl
Last edited by Karlthevet; Mar 13, 2018 at 04:39 PM.
Mar 14, 2018, 12:02 AM
Registered User
Quote:
Originally Posted by Karlthevet
Hi All

As I see it, the intent of the rule is that no expensive laminated cloths are used and that the sails themselves remain single surface - in the spirit of keeping the costs down, facilitating home made sails and maintaining a level playing field.

I guess the devil is in the details, but for me a layer of cloth is a single discrete sheet that cannot be separated visually. I consider Trispi to be a single layer cloth because the mylar film has been bonded in such a way that it is effectively welded into a single layer. The scrim reinforcement is not a layer in itself - it's part of the cloth structure.

If you were to consider Trispi to be a non-single ply cloth, for the sake of consistency, you would have to consider any modern woven sail cloth to be non-single ply. Icarex consists of a warp and a weft and is coated on both sides (that could be held to be four layers using this approach).

Both Sirius and Cat Sails offer DF 65 sails cut in scrim mylar (Trispi). Cat Sails are highly experienced and I doubt they would manufacture a sail that was illegal. I cut my own sails (for my DF 95). I've used both standard mylar film and Trispi.

...

Cheers!

Karl
Yeah sounds reasonable but... A ply is structural. A UV coating is not and so would not generally be considered a ply. Tripsi and other Mylar "sailcloth" is made from 3 structural layers. It is hard to argue that it is a single ply just because the layers are stuck together. Icarex is a single layer of polyester coated with PU to make it UV and water resistant. I think you would be hard pressed to argue that is 3 ply. Plywood cannot be reasonably separated either and you don't add a ply if you paint it. Film Mylar is like the V6 stock sails are clearly single ply as were the original rip stop nylon sails.

If the single ply rule does not make Tipsi illegal for one design use then what does it mean?

A race committee has to interpret these rules. If I had rip stop nylon sails and you had Tripsi sails and you won it seems a reasonable protest to say you have illegal sails. We don't want that sort of protest because it spoils the day. Race committee needs guidance up front as to what is allowed and what is not and you need the same before you make or buy sails that are potentially illegal for one design use.

I'm not saying Tripsi or other laminated sails are illegal because I don't know. However it does seem that a race committee may reasonably consider them multi-ply if a challenge is made.

We need a rules clarification to either remove the "single ply" restriction or make it clear what it means.
Mar 14, 2018, 04:28 PM
Landlocked Sailing Addict

Legal Sail Material


Hi

I disagree with your plywood analogy. The layers in plywood are clearly separate (and have a layer of glue between them). You can delaminate them by breaking the glue bond (either with moisture if the glue is not waterproof, or by force).

If you were to take a cross section of Trispi and look at it under a microscope, you would see a single layer where there was no scrim reinforcement. The scrim sits in tunnels formed when the cIoth is manufactured.

I guess what's happening here is that you and I are expressing our own interpretations of what this rule means.

I agree with you that there needs to be a ruling on the use of cloths such as Trispi. I certainly wouldn't want to be building illegal sails, and neither (I imagine) would the professional sail makers.

So, "Gang" (John Tusingham, Mark Dicks, Mike Weston), is a DF sail made of Trispi (or its Mylar scrim equivalent) legal under the DF rules?

Cheers!

Karl
Mar 14, 2018, 05:19 PM
Registered User
http://www.iomclass.org/measur.../sa...ment_guide.pdf

From that document, a single ply is determined as follows
"A ply is a sheet of sail material made up of one or more lamina. For example a layer of film bonded to a woven fabric is a ply; in fact a laminated ply. A sail with its body made from one sheet of this ply would be a single-ply sail. If two sheets of the material were used next to each other this would be a two-ply sail."
Meaning that a sail can have multiple laminations, yet be a single ply - which means materials such as Tri Spi, Code Zero, CPM505, Cuben Fiber are all permitted single ply sails - even though that have multiple materials laminated together.
i am reliably informed this is the document the Df rules committee use to define ply.
Mar 14, 2018, 05:57 PM
Registered User
Well really the question is what does "single ply" mean in the DF65 sail construction rule and what is it supposed to prevent people from using?

If I'm on a race committee and there is a challenge, what do I allow or not allow and how do I make the determination?

Trispi and similar sail cloth are made from 3 layers. If Trispi etc. is allowed, is there any point to the single ply restriction and could it be removed?
Mar 14, 2018, 06:28 PM
Registered User
Quote:
Originally Posted by knoby
http://www.iomclass.org/measur.../sa...ment_guide.pdf

From that document, a single ply is determined as follows
"A ply is a sheet of sail material made up of one or more lamina. For example a layer of film bonded to a woven fabric is a ply; in fact a laminated ply. A sail with its body made from one sheet of this ply would be a single-ply sail. If two sheets of the material were used next to each other this would be a two-ply sail."
Meaning that a sail can have multiple laminations, yet be a single ply - which means materials such as Tri Spi, Code Zero, CPM505, Cuben Fiber are all permitted single ply sails - even though that have multiple materials laminated together.
i am reliably informed this is the document the Df rules committee use to define ply.
Well that may be the key.

So "ply" in this context means layers are not joined together across their entire surface. In fact that seems a simpler and better definition rather than saying laminated layers are not plys.

Of course, it begs the question, why have a single ply rule at all...seems pointless at this scale.
Mar 14, 2018, 06:36 PM
Registered User
and by that definition Dyneema qualifies as single ply.

We only have that based on someone being "reliably informed" but it makes sense at least.
Mar 14, 2018, 06:47 PM
Landlocked Sailing Addict
Hi

Quote:
Originally Posted by pressalltheknobs
Of course, it begs the question, why have a single ply rule at all...seems pointless at this scale.
It prevents (among other things):

1. Double surface sails (you can set up an asymmetric aerofoil effect that is more efficient).

2. Sails with partial two or more ply areas (as a weight saving measure - you build up a flat cut sail out of very light cloth, then double or triple ply areas that are going to be under more stress, such as the mainsail leech).

Such sails are way more complicated and expensive to build and may provide a performance advantage - which would be against the spirit of the DF rules.

I've gone to the DF website and put in an enquiry about this, but, based on what "knoby" has to say, it sounds as though I won't get protested for my sails. (However I still have to sail my boat properly..............)

Cheers!

Karl
Mar 14, 2018, 06:52 PM
Landlocked Sailing Addict
Hi

Quote:
Originally Posted by pressalltheknobs
and by that definition Dyneema qualifies as single ply.

We only have that based on someone being "reliably informed" but it makes sense at least.
Having looked at the website to which you linked, this cloth is formerly known as "Cuben Fibre" anyway. I believe it's already been tried on DF model yachts - not sure how well it went.

Cheers!

Karl


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