Sail trim upwind, wrinkles

L

LaserBill

Member
I seem to have very noticeable wrinkles from the mast joint (where the 2 pieces of mast join) toward the clew in all but the lightest wind. Today sailing in about 10 mph it was quite prominent. The wrinkles can be removed by using the cunningham, which I usually try to avoid because I am big enough that I don't need much de-powering at that wind speed. Should I use the cunningham to remove the wrinkles, should I ignore the wrinkles, or is there some other solution? I am wondering if there is something wrong with my mast joint, although it looks fine. I don't see these wrinkles on most of my competitors' sails.

Thanks for any advice.
 
the wrinkles will make air flow not as great. so make it de power a bit by pulling in cunningham to remove wrinkles that make you slower. and you wont notice the slightest speed difference. but dont put too muchcunny or youll see wrinkles the other way.
 
The wrinkles are not the end of the world, but the sail will look and feel a whole lot better if you remove them using the Cunningham. The obvious peril here is that over use of Cunningham in the medium wind range will have a disastrous effect on pointing ability. Try just giving your Cunningham a yank to remove the creases, but don’t cleat it off. This should remove the creases without having the Cunningham too tight.

I find this technique works well; I only have to yank the Cunningham when the creases come back, which is usually every 5 minutes, or when the wind strength changes, in which case you should be looking to adjust the controls anyway.
 
The sail is probably blown out somewhat. If you're really concerned, buy a new sail. If not, I think Suthera's idea is the best.
Some wrinkles along the luff are normal for medium winds anyway. If they go all along the sail, it's definitely blown out. The luff wrinkles don't change airflow much becasue there's a separation bubble there and no attached flow for the wrinkles to mess up. Wrinkles on the sail won't change the airflow much, but it shows that the cloth is stretched where it shouldn't be.
 
Thanks for the input. Following computeroman2's comment I will say that the sail should not be blown out, it is less than a year old, probably used less than 10 times. These wrinkles have been present since the sail was first used, and also present with an older sail. I am still wondering if the mast joint contributes to the wrinkles, and if so whether there is a remedy for it.
 
There is a class rule that allows you to use packing tape around the mast collar of the upper section to make the fitting between the two sections tighter. In my opinion a tighter fitting mast section does make a difference in the amount of luff wrinkle. It could be in my head, but whatever keeps your head out of the boat will help you get to the next mark faster.
 
Edit ---- looks like Rob and I were writing around the same time... The reason the packing tape helps reduce the wrinkles is the extra slop at the joint is in effect adding more mast bend at the joint and since the overbend wrinkles are indicating a lack of sailcloth between the joint and the clew, making the mast bend more then it has to is going to just compound the problem
---edit

If the fit of your upper/lower is especially loose, add some packing tape to the plug and the collar of the upper - a lot of slop at the joint also adds to the overbend wrinkles.

The pulling of the cunningham and then just easing off is the right way to go.
Why this is nec: With the cunningham off and the mast straight (no vang, sheet eased) the luff sleeve relaxes and the tack and sleeve move up. Then you sheet in and bend the mast again,which leaves the luff sleeve stuck in the relaxed , tack raised position.

I disagree with computerman2 about the wrinkles indicating a blown-out sail. If anything a blown out sail has permanently stretched more in this area and does not show the overbend wrinkes as much as new or slightly used sail. The indicators of a blown out sail are a loose leech, and having to throw more vang on to flatten the sail when two blocked.
 
Thanks for the additional input. I have one layer of Teflon tape on the plug and collar of the upper section. I will check for slop and add more tape if necessary. I like the idea of tensioning the cunningham and then easing it to pull the luff sleeve down the mast. It just occurred to me that spraying the mast with McLube or similar dry lube may also help let the luff come down. Has anyone tried this?

Thanks.
 
I'm a big McLube fan. Put it on the mast, in the mast step, on the boom and on the sail to keet the tails from sticking when they get wet.
 
Packing the mast joint seems to help - some recommend more tape on the bottom (lower) front side of the topmast base plug to cant the thing slightly foreward (negative pre-bend) - not sure if this is legal.

The crease from mid joint to clew can get worse if the mast is bent when you adjust the cunningham (the luff sleve doesn't slide evenly)

Some people in some conditions try to get a deep crease in some conditions - claiming they can the sail above the crease independently from that below in ways not possible without this crease shelf.

Others endure some creases in certain conditions, just as they endure minor luff wrinkles when trying to get maximum 'bag' in light conditions where swell or chop is out of proportiong to breeze (i.e. left over chop from previous breeze etc).
 
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