26X Mainsail shape distorted

[R Rae]

We were out enjoying a good 10-12 mph breeze the other day, cruising along at 6.5+ (GPS) knots when I happened to look up the mainsail and noticed that about half way up on the convex side the sail was becoming slightly concave towards the leach. We were on a close reach and heeling maybe 18 degrees. Both outhaul and vang were reefed up pretty tightly, and except for that felt pretty good about performance.

My question is, is this a normal condition one should expect or is something else going on...?

Any input sure would be appreciated.........Thanks

[Don T]

Hello,
Probably had the jib / genny in just a tad too much, back winding the main. When in doubt......ease it out.

[Gerry the fish]

I have seen the same when the main starts to luff. It doesnt always happen - but I think if sail conditions and wind are just right.

You say on a close reach - Im guessing if you sheet in the main at this point then you start to heel too much. Then your next step is a reef in the main - which I know I avoid. But if you have a lot of weather helm, you may go just as fast with a reef in the main and a balanced boat.

These are what I do when it happens to me
- sheet in (mainsheet) note the vang may not be doing anything at a close reach.
- tighten the outhaul to reduce sail bagginess
- bare off a little - may be "pinching up" too high
- possibly a little overpowered (6.5 knots is fast) if Im fighting the helm then time to reef.

From my experimenting the jib is not the issue.

[R Rae]

Thanks for the info. Don/Gerry. I could have added that both sets of tell-tales were streaming out beautifully also, if conditions ok tomorrow, I'll be out trying out the various options offered.

Cheers...........Ron

[craiglaforce]

Some things you might try.

Make sure you have a fully hoisted mainsail by releasing the mainsheet and vang and manually lifting the boom before going to the mast to raise the mainsail.

Try adjusting outhaul tension. Might be a little too tight for the wind conditions. Lots of folks ignore this adjustment 'cause it doesn't have a fancy adjuster, But it is an important adjustment .

I am guessing you will find these first 2 will fix it. But a couple more things to try would be


Make sure topping lift is released.

Make sure leech line is released unless leech is flapping.

Others mentioned backwinding which is another possibility, but I am guessing you would have noticed that pretty easily.

[delevi]

Backwinding is quite common, however evident along the luff of the mainsail, not the leech. I think everyone else pointed out the possible causes. I suspect it is either the leech line or topping lift. If the topping lift is holding up the boom at all, vs the sail, it will distort sail shape. I always slack mine before hoisting, then take it back up after I drop the main. If the leech line is over-tightened, it will cause a fish-bowl shape in the sail. It is only useful when the sail starts to blow out and the leech flutters all the time. Checking for backwinding is easy. Just ease out the jib sheet (even if it luffs) and see what happens to the main. If none of these suggestions work, your sail me be blown out Been there, done that.

Good luck,
Leon

[Rob S]

You might also check for shrunken bolt ropes....... there have been a lot of posts about a shrunken luff bolt rope but not about the foot bolt rope which is probably more hidden within your boom.

I have had both. At the beginning of this season my main looked like a scrunched up handkerchief. I checked the luff bolt rope and snipped the stitches at the tack....... the rope ultimately retracted about 7 inches and a lot of the wrinkles disappeared from the main. However I suspect this would not cause the symptoms you describe.

But the roach of the sail still looked a mess. On further investigation I found that the foot bolt rope was also shrunken to the extent that it was causing a tear at the clew. I snipped the stitches at the clew with the result that the roach of the sail became much flatter and taut. Worth checking out.

[R Rae]

Outhaul adjustment-(Craig) This could be a problem since I recently installed a 6:1 ratio adjuster, with line going back into cockpit, and really enjoy cranking on it. Hhmm!

Don't have a topping lift.

Leech  will flap under any windy conditions unless I yank 'er down.

I manualy pull main halyard from within cockpit, but maybe I should do a final tweak using the winch in heavy air...?  Yes??

Jib sheet position (Don/Leon)  I've bin reading too much    about 'the slot' recently (between jib & m'sail) and could be getting carried away with all this new found knowledge !!-  I'll ease it out maybe just a tad.

Foot bolt rope (Rob)  I am now running loose footed since Spring time, and did notice the foot bolt rope to be tighter than the adjacent sail material....Actually thought it looked good and perhaps would reduce spillage below the foot.....Is this just my wishful thinking and if so, how much of the stitching starting at the clew should I remove...?

Thanks for your time........Ron

[delevi]

Leech  will flap under any windy conditions unless I yank 'er down.

I hate to say this, but this is a tell-tale sign of a blown out sail. I went through the same thing a couple of years ago when I replaced my sails. The leech is where much of the power from the mainsail is pushed out. If you need the leech line to control the flutter, you're focing shape into the sail, thus distorting it, which somewhat compounds the problem, since a blown out sail has a stretched out shape to begin with. I doubt it's the bolt rope. At least in my case, I cut it and it did nothing at all. If it looks bad with halyard, leech line and outhaul cranked hard, it's toast. Will still work, per your 6.5 kts close reach, but once the winds pick up, the boat will be really hard to control.

You might be able to get a sailmaker to re-cut the sail... or.... use this as an excuse to get some quality sails. Of course, you can also just live with it. 6.5 kts is darn good with a blown-out sail.

[Rob S]

Foot bolt rope (Rob)  I am now running loose footed since Spring time, and did notice the foot bolt rope to be tighter than the adjacent sail material....Actually thought it looked good and perhaps would reduce spillage below the foot.....Is this just my wishful thinking and if so, how much of the stitching starting at the clew should I remove...?

I don't know if it's wishful thinking or whether this is indeed your problem but the stitches in question are at the end of the foot bolt rope end near the clew. They aren't the seam stitches, you can see them going back and forth through the center of the end of the bolt rope for about the last 2 inches, It's a simple matter to snip them and pull them out at which point the bolt rope will become free within its sleeve. When I did this, the rope retracted about 3 inches within its sleeve. I added another 3 inches of another rope and patched it all up with sale tape as a temporary repair before I get it properly repaired over the winter.

Before I did this, the outhaul was pretty much ineffectual....... I was just stretching a shrunken rope without tensioning the sail cloth itself. After, the outhaul did what it is supposed to do, quite a big difference.

But proceed carefully because Leon is right...... 6.5 kts is pretty darn good...... hull speed!

[R Rae]

The response to my mainsail questions has been awesome.........Thanks everyone.

Snipping the bolt rope at the clew probably will be my next move, as I guess it being tighter than the adjacent sail isn't a good thing. However, Leon's suggestion about a quality sail (KH-pentex, maybe) could make it a candidate for next years budget !!

Cheers..............R

[Rob S]

Well, if you do snip the stitches, let us know the effect!...... good for the collective knowledge here.

Like I said, there are plenty of posts on doing this to the luff bolt rope but not the foot bolt rope. In my case there was no doubt that the foot bolt rope had shrunk because it was so bad it had started to rip itself and its sleeve from the rest of the sail at the clew.

[R Rae]

Rob, unless I chicken out at the last moment, I am planning on having a go with the snips in a few days.

Perhaps I should take a before and after shot before 'doing the deed', then post anything worthwhile.

Cheers.....

[baldbaby2000]

Try adjusting the main halyard tension; it might be too tight. Or loosen the Cunningham if you have one.

[R Rae]

Could halyard tension be pulled too tight, by manually pulling the halyard sheet.....?  I've been thinking of using the winch for a final tighten.  Does anyone out there routinely use the winch for heavier than normal weather...?
Now, from recent comments I am thinking maybe my 6yr. old mainsail luff bolt rope  has shrunken, and should be checked out.  (I'll have a look in a day or two).
Please note it took me 5yr. just to learn how to get the F..#@@#%..ing " X " off of the trailer....... ,so I don't think I've abused, and stretched the hardware too too very much.

I gather that the slugs should be sewn only to the sail-cloth and not to include the bolt rope....Will check.

Baldbaby, can a Cunningham be easily installed in a std. Doyle set-up...? I've often wondered what it would do for the normal 26X arrangement.

Cheers....Now it's time for a well deserved nap........R