J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Dacron Main

The new Vectron main was used on the Rhapsody maiden voyage last weekend. I'll get some calibration data and pictures over the next week to establish a baseline for aging characteristics. Here are teaser photos, with more available on the Rhapsody blog site

Based on comments from Bob Rutsch, I've since adjusted the headstay so it is max class legal length, and tightened the uppers an additional couple of turns to give more mast prebend. The results looked good Friday with winds 15-20 gusting to 25.

If conditions support this week, I'll get pictures and take data.

If you haven't figured it out, I'm passionately in favor of changing the rule on main sail cloth from Dacron to unrestricted.

Over the last couple of years I've done my best to poke and prod in an effort to stimulate input for both the pro's and con's of changing the class rules for main sail material.

Shortly, I will be writing to my representative on the BOG to submit a recommended rules change at the next BOG meeting. The following is a draft of what I will submit. For reference, I have also included the current rules regardining main sail.

There are two reasons for calling this a draft
1. I welcome input
2. I question if there should be a minimum sail cloth weight; but if there is, what should it be - I have a call into my sail maker for his thoughts and am awaiting a response. I will post the sailmakers commnets as I recieve them

Here's the Current Rule - to save a lot of reading, I will recommend changing only section 5.12.1.2 and possibly section 5.12.2.1. Regardless here's the current rule

5.12 Sails

5.12.1 General

5.12.1.1 Sails shall be constructed and measured in accordance with the ISAF sail measurement instructions except where otherwise stated herein.

5.12.1.2 Mainsail shall be manufactured from woven ply polyethylene terephthalate ("PET"), such as Dacron®, or woven ply polyethylene naphthalate ("PEN"), such as Pentex®. The spinnaker shall be manufactured from woven ply nylon.

5.12.1.3 Sailcloth in the #1, #2 and #3 Genoa is not restricted.
This change in approved sailcloth goes into effect no later than October 17, 2005. Individual J30 Class Districts may adopt this change for local events at an earlier date.

5.12.1.4 Sail numbers shall be placed immediately above the third batten (#2 sewn from the head of the mainsail) on the #1 and larger genoa in line with the mainsail numbers and on the spinnaker. The starboard or forward number shall be on top.

5.12.1.5 Genoa #2 is optional and does not need to be on board while racing.

5.12.1.6 Numbers shall be of the following dimensions in solid black, red, green or blue: height = 380mm, width = 254mm, thickness = 57-77mm, spacing = 77mm.

5.12.1.7 Windows. There is no limit on the number or design of collision, telltale, or spreader tip windows on the mainsail or genoas.

5.12.2 Mainsail

5.12.2.1 Minimum cloth weight is 6.25 oz.

Here's my DRAFT RULE Change (see 5.12.1.2 and 5.12.2.1 for my recommended changes)

5.12 Sails

5.12.1 General

5.12.1.1 Sails shall be constructed and measured in accordance with the ISAF sail measurement instructions except where otherwise stated herein.

5.12.1.2 Sailcloth on the Mainsail is unrestricted. This change in approved sailcloth goes into effect no sooner than 1 October 2012. Individual J30 Class Districts may adopt this change for local events at an earlier date. The spinnaker shall be manufactured from woven ply nylon.

5.12.1.3 Sailcloth in the #1, #2 and #3 Genoa is not restricted.
This change in approved sailcloth goes into effect no later than October 17, 2005. Individual J30 Class Districts may adopt this change for local events at an earlier date.

5.12.1.4 Sail numbers shall be placed immediately above the third batten (#2 sewn from the head of the mainsail) on the #1 and larger genoa in line with the mainsail numbers and on the spinnaker. The starboard or forward number shall be on top.

5.12.1.5 Genoa #2 is optional and does not need to be on board while racing.

5.12.1.6 Numbers shall be of the following dimensions in solid black, red, green or blue: height = 380mm, width = 254mm, thickness = 57-77mm, spacing = 77mm.

5.12.1.7 Windows. There is no limit on the number or design of collision, telltale, or spreader tip windows on the mainsail or genoas.

5.12.2 Mainsail

5.12.2.1 Minimum cloth weight is ???.

whatever our competition uses at a PHRF event, should be the goal.

Also consider that if the number 2 jib is not required for OD racing ... why keep it in the rules at all?

The #2 is strictly optional and legal by being kept in the rules. Eliminating it from the rules would make it an illegal OD sail. We don't pass rules that render anything that was original design illegal. Some people swear by it - ask Nemesis....

roger, roger ... off shore a 140 is my favorite on a roller.

But it does present an interesting problem ... If I were to race OD with a roller and a 163 ... could I not reef it? during a race? to any point between full and say a blade?

[disregard that it looses efficiency. in higher winds there are tradeoffs between a imperfect rolled sail and an overpowered sail. ]

Vic - I know of nothing in the rules that precludes that. Permitted alternatives per Rule 5.8.1.1 Jib roller furling system to facilitate sail handling.

Implies it's allowed, if you like to have that weight aloft. Most racing OD don't.

Let's keep this thread focused on the main discussion that Russ posted and take the other stuff to another thread if you want to discuss further.

roger, roger ...

So try this ... what would Rod Johnstone do, if he had to do it all over again today?

Oh boy. Unrestricted sailcloth in the main is a real bad idea. My personal experience in laminated sailcloth is that the quality of it is getting WORSE. It really wants to come apart and quickly. Again, when the mylar scrim cloths first came out, they seemed to last a long time, and hold their shape. The current group of laminates seem to be getting worse. PBO was the last sailcloth that seemed to hold up for a length of time. The Hood vectron woven sailcloth looks pretty interesting. I tend to agree with Dave Ullman, who used Dacron mains in the Melges 24 for a LONG time. Dacron tends to give when over powered, helping the boat to remain flat. If you order your main with the top two battens full length, ROLL the sail, do not flake it, and do not allow it to flog, it should last many seasons. (you also should roll a laminated sail.) I also prefer to order the sail with extra bolt rope hanging from the bottom of the luff, and not sewn to the sailcloth. Lots of mains that owners have said are bad have simply had the boltrope shrink. I have taken mains two years old into top competition in the J-24 class and was competitive. Also, remember that if you are racing PHRF with an ODR rating, and you are using a non class legal sail, your ODR rating is invalid. ODR by its definition states that you are racing a class legal boat with class sails.

Art - some good info in your post. The PHRF - OD sail rule depends on what PHRF body does the rating. Here on Narragansett Bay (PHRF-NB), the PHRF rating is unchanged by sail cloth material, only by dimension changes in the sail. A few years back we posed the question to the rating body because of 0.5oz spinnakers. The rating body came back with the ruling they did not adjust ratings based on changes in sail materiel. I am aware of other rating bodies that work similarly, and some that will adjust the rating if the material does not meet OD requirements. My Vectron main has no PHRF rating adjustment. If I had a string sail, it would also rate the same.

You should read the minutes from the 5 August 2010 Board of Governors meeting bullet #6 where Rod Johnstone commented on one reason why J/Boats have used light weight laminate sails. Rod weighed in on the discussion and thought that the laminates were getting more cost competitive.