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

I did not intend to insult you Russ nor did I anticipate learning about your personal hygiene. It was easy enough to review the evidence posted in this thread and make a simple projection. My point is that what might be best for you, Vic, and other PHRF racers may not be what is best for the eighteen one-design racers sailing in my fleet. Many of them are gearing up for the NA's in September and have planned their sail purchases accordingly. My goal is to continue racing one design in our class and fleet. I'm also growing weary of this topic which long ago reached a stalemate; but I'm not the one who keeps resurrecting it.

Here's some dialog that I have had with my sail maker regarding their input on sail cloth weight for a high tech (string) main

Here's my first e-mail to the sail maker:
The requirement for a Dacron main is a sail cloth weight of 6.25 oz. What is the cloth weight of the Fusion X main that I bought? If I wanted to purchase a Fusion MT main; what is the recommended sail cloth weight of the Fusion MT (in other words, would it be different from the cloth weight of the Fusion X)?
Is there a minimum sail cloth weight you would suggest for a high tech, general purpose main? I appreciate your guidance


Their first response:
Most classes that allow some sort of high-tech sailcloth or sail construction do not use a minimum cloth weight, but rather a minimum finished sail weight. Something around 9-10 kg would work for a J30 main


Their follow up response:
This is an interesting question as I guess most OD classes recommend a bag weight. We looked up several resources and it looks like dpi would be in the 14000-15000 range. High tech string sails can be in the 12000 range. Your sail is a Flex 16, which equals 5.5 Sm Oz.


Not understanding what they told me I sent the following:
Thanks so much for the input. I apologize that I am, however not able to follow all the terminology.
Bag weight I think I understand = weigh the finished sail. I am not familiar with the other terms such as dpi and Sm OZ.
Backing up for a minute; current J/30 Class rules for the main read
5.12.2.1 Minimum cloth weight is 6.25 oz.

The question then is, if the class allows non-Dacron sails what sail cloth weight should be used or if sail cloth weight is not appropriate what measure should be used (if any).
I saw the note that a J/30 main should come in at a finished weight of 9-10kg (I assume tht is bag weight). Can you be specific on weight; is it 9 or 10kg or something else? You have my sail at the loft, it's missing the battens but it could be weighed if you need a sail to weigh?

Next question. When I bought the sail, If I had upgraded to the more expensive Fusion MT alternative, would the Fusion MT sail have weighed the same or less?

To the forum;
I'll keep working on this. If anyone else has input from a sail maker on what wording to use for a high tech main sail weight please jump in here.

Great work Russ!!

"Bag weight" can be rather fungible. One could make a 5kg sail, and add a 5kg "grommet", and it would weigh 10kg.

gsm (grams/sailmaker yard) or smoz(ounces/sailmaker yard?) would be a better measure.

All I know is I ordered a new dacron main today. I race only PHRF. Thought the extra thousand for a tech main was better put towards a bottom overhaul or a new #1

Ooooooh new main Scott? Who'd you buy it from?

UK. Boat show discount (25%) so it was the best price, plus Tim Knight used to own a J/30 and raced on Radiant Heat for a while I think so that is worth something to have a sailmaker who knows your boat.

With regular pricing, both Sobstad and Neil Pryde came close. North was $1000 more. I never even heard back from Evolution

Just got more input from my sailmaker. Look to my 03-09-11 post if you want to follow this dialog from the beginning

From the sailmaker:
Here is a bit more info that hopefully will help you and the class make progress towards the proposed changes in mainsail material.

Sm. Oz. is just an abbreviation for sailmaker's ounces, the generally accepted measure of the weight of cloth in the sailmaking industry.

"dpi" stands for denier per inch. With dpi, you are measuring how much fiber is in a given cloth or a specific sail. High-tech "string" sails (Fusion M, 3DL, D4, Tape-Drive, etc.) are generally referred to as having a certain dpi. For example, North Sails offers a J 105 class jib with 16800 dpi, that meets the class minimum finished sail weight of 23.8 pounds. The problem with dpi, with regard to string sails, is (unlike cloth weight) there is no standard throughout the industry on how exactly dpi is measured. So, jibs from 3 sailmakers for the same boat, each one at say 15000 dpi, could all be quite different in finished weight.

Your last main was built with cloth that has an overall dpi content of approx 16000.

Your last main weighs approx 29 pounds (13kg). If it had been a Fusion M main, it would have certainly weighed less. The 9-10kg number is an estimate for a J30 main, based on comparing the minimum mainsail weights in several other classes, and obviously taking area into account - Rick

To the class... any thoughts on how to deal with this? Perhaps a minimum DPI and a minimum bag weight?

I would think a finished weight would be the easiest to manage. Of course it will be lighter than Dacron sails so we are still back to the orginal question if dacron mains will still be competitive at the national level then.

To Scott/Natural High
I'm honestly not trying to take a poke here... I would however, like to ask some tough questions that I think are important to this discussion.

Earlier you stated that you race only PHRF; yet you bought a Dacron main to save (in your case) $1000.
So, some questions are;
1) Did you buy Dacron simply because of the cost?
I know, from when I appealed the J/30 rating with PHRF -Lake Erie that PHRF does not cut any slack for less than the best. 2) Did you buy the Dacron sail thinking that you could still be competitive in PHRF - that high tech wasn't going to help you?
3) Did you buy the Dacron sail thinking you are a casual racer and therefore Dacron was good enough

I could probalby think of a bunch more ways to ask questions around a point I'm trying to understand.

What I'm trying to understand is your thought process that in an arena where hi-tech mains are allowed you bought Dacron. Yet...you ask the question as to whether Dacron sails will be competitive at the national level if hi-tech sails are allowed.

Backing into this another way, if Dacron won't be competitve with Hi-tech sails in the nationals, then shouldn't Dacron be non-competitive in PHRF too? And if so, why then did you buy Dacron to race PHRF?