Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 02-04-2009, 18:52   #16
Registered User

Join Date: Sep 2007
Location: Colombo
Posts: 1,059
Quote:
Originally Posted by MidLandOne View Post
The creases are almost certainly due to bias distortion in the sail cloth used for a radial cut sail and no matter what sail trimming or playing around with battens you do will eliminate it.
Should, of course, read - "The creases are almost certainly due to bias distortion in the sail cloth used for a radial cut sail and no matter what sail trimming or playing around with battens you do THAT will NOT eliminate it."
__________________

__________________
MidLandOne is offline   Reply With Quote
Old 02-04-2009, 19:12   #17
CF Adviser
 
Bash's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
bias distortion

bias distortion can only be caused by a load on the sails. That load has to be coming from somewhere. Given the description of the conditions/situation when the photo was shot, it either has to be from luff tension or batten tension.

This is not, by the way, an unusual problem for a woven tri-radial, especially if it's built to stretch properly.

Talk to the sailmaker, he'll help you sort this out.
__________________

__________________
cruising is entirely about showing up--in boat shoes.
Bash is offline   Reply With Quote
Old 02-04-2009, 21:59   #18
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
I agree with MidlandOne: talk to another sailmaker too....

ciao!
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 02-04-2009, 22:05   #19
Registered User

Join Date: Aug 2008
Location: Queensland. Aus
Boat: Privilege 37
Posts: 43
Thank you all for the imput. A few answers so far, the sail cloth is definitely not on the light side in fact it was one weight heavier than the recomended cloth and ended up fifteen kgs heavier than its predessor. The battens are new, The sail shapes up very well when sailing and does not look too full in the head, especially as the wind increases.I have had someone up the rig while sailing to do batten adjustments and the sailmaker was on board, It did appear to make a very slight decrease in the creases. I now wait for his next thoughts this week end. Thanks
__________________
privileged is offline   Reply With Quote
Old 02-04-2009, 22:43   #20
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Yes I was thinking the head might open up somewhat when sailing. Also, we have a hydraulic boom vang which will keep the boom up in the situation where you took the photo so the sail doesn't have the weight of the boom which will make the head look different. I think the creases might go away when you lift the boom or sail with more wind.

I still wonder how the leech will behave in higher winds, like 25 knots true. If it opens up too much even after increasing luff tension, you know you can have stiffer battens. A trick often done in that case is to make the back-end stiffer by taping a piece of batten onto it (like the aft 2/3 of the batten). This is like simulating a tapered batten.

But overall, I think is shape is good, it looks a lot like mine (from Elvstrom-Sobstad). Also, if you had laminate before you will love this as we don't have a single spot of mildew on it after 4 years. The laminates we had before looked black like carbon sails because of the mildew between the layers....

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 03-04-2009, 05:22   #21
Registered User
 
Tempest245's Avatar

Join Date: May 2008
Location: Piscataway, NJ
Boat: 34 Sabre Tempest
Posts: 937
Is that aft line...a topping lift? it looks pretty taut to me. I have no other opinions regarding the sail construction.
__________________
Tempest
Tempest245 is offline   Reply With Quote
Old 03-04-2009, 12:13   #22
Registered User
 
Sail Warehouse's Avatar

Join Date: Feb 2009
Location: Monterey ca.
Boat: Manta 40- "Savannah"
Posts: 47
Images: 9
I think MidlandOne is probably correct at least in theory. The cloth used was probably not the best choice for the application. This could be caused by using a fill oriented cloth in a radial application when it is intended for a cross cut application as I think Midland may have been referring to, (the cloth is being loaded in a direction that it is not very stretch resistant). It could also be from using a cloth that was a bit too light or just too stretchy for the application. That said, it really isn't that bad looking. A lot of OEM sails on production boats look much worse than that.

Jim
__________________
Sail Warehouse is offline   Reply With Quote
Old 07-04-2009, 09:29   #23
Registered User

Join Date: Apr 2009
Location: France
Posts: 5
Yep , creases are from biasstretch . What's the cause ?? There is more than 1 possible answer I think .

The sailmaker used horizontal hydranet in a triradial application instead of the radial product . ( how does the cloth feel , soft of hard ?? )
It is radial hydranet ..... but a bad roll . .
The battens are overtensioned in trying to overcome the problem... zones of deformation from leech to luff at the next following batten .
Upper 2 battens are too soft , or sail too full in upper quarter .
To much build in shape (in the seaming ) with battens tapered at 30% instead of 45 to 50 %
Or to much luffcurve at the top . (is simple to remove ) .

The good news .... creases will dissapear once you are sailing .
__________________
Rafale is offline   Reply With Quote
Old 07-04-2009, 12:54   #24
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Ahhh.... I never realized that there are different types of HydraNet. My sails are very stiff, almost as stiff as the laminates I had before. But my sails are build bullet proof too, they are 3/8" thick between the plates of the headboard!

I see Spectra fibers both horizontal and vertical at about 3/4" distance, like a net. In addition to that I think there's also more spectra fibers for the "fill" of the weave which run vertical. I need to check panels in the middle to see how they are cut... maybe the fibers are still horizontal & vertical but I think the idea is that they run in the same direction as the panel because that is what tri-radial construction is about.

When I first saw the photo I thought that the tension on the sewing machine might have been wrong but the creases stop before reaching the seams.

ciao!
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 19-04-2009, 09:03   #25
Registered User
 
Steve_C's Avatar

Join Date: Apr 2009
Location: San Antonio, Texas
Boat: Soon to be a Cat
Posts: 212
If you tighten the topping lift do the creases get worse? or better? Changing the downward pressure on the the sail and noting the changes would tell a lot. I looks like the panels are not properly oriented to match your Mast/Boom geometry.

Just a thought...
__________________
Steve_C is offline   Reply With Quote
Old 15-02-2010, 09:11   #26
Registered User

Join Date: Feb 2010
Posts: 1
hydranet

As a sailmaker I have encountered the problem you are having with this sail. Hydra net is a fantastic cloth although it does have a problem.
Basically when it is being seamed together the needle gets deflected when going through the parts of spectra in the cloth causing distortion, which is what we are seeing in the photos. The good news is that what your sail really needs is some decent breeze through it this should settle everything down. So go sailing in about 18+ knots upwind and you will have a good shaped sail.
__________________
gav reloaded is offline   Reply With Quote
Old 18-02-2010, 22:05   #27
Registered User

Join Date: Aug 2008
Location: Queensland. Aus
Boat: Privilege 37
Posts: 43
thanks Gav . I have sailed in plenty of wind over the last twelve months with no change to the sail . So the sail maker decided to make a new sail for me thinking the cloth was faulty. And guess what after one week same creases appear.. so where to now. I dont know He now tells me that the cloth is not the right choice for the sail design with that amount of roach and that the performance of the sail will not be affected . we will see
__________________

__________________
privileged is offline   Reply With Quote
Reply

Tags
mainsail

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mainsail Reefing chucktro Seamanship & Boat Handling 9 26-02-2010 09:53
Numbers on Mainsail? Tiki 38' General Sailing Forum 13 27-01-2010 16:20
Mainsail Sticking nov2662harley Deck hardware: Rigging, Sails & Hoisting 7 11-10-2009 17:20
Mainsail Replacement ldw Deck hardware: Rigging, Sails & Hoisting 10 19-07-2009 21:09
mainsail harumph1 Deck hardware: Rigging, Sails & Hoisting 22 23-01-2008 12:02



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 08:47.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.