A ? for Todd Bradshaw

[J. Dillon]

http://www.imagestation.com/picture/sraid33/pf955387400c3c1cd8de48af5aef41433/fd3b4e19.jpg
Todd,

My brail line even thou slacked spoils the leech of my 100 sq ft main sprit sail. Especially on the wind. I use 1/8" nylon for this line. Is there any way to effect a smooth leech ? How about a small batten ? Any thoughts or suggestions ? Thanks

JD

[Todd Bradshaw]

Jack,

You could try temporarily rigging a batten with a strip of wood or a paint mixing stick held on with a couple strips of clear packing tape, but I have a feeling that it may just result in a different bad leech shape, hinging at the front of the batten. Don't leave the tape on any longer than you have to and if possible, try it on a day that isn't sunny and hot to keep the goo on the tape from coming off on the cloth. Since leech battens are a constant source of chafe, I hesitate to suggest permanently adding one unless it really seems to fix the problem.

I haven't been able to come-up with any simple ideas. It might be possible to rig some sort of brail-brail, that pulls the slack lines up toward the peak grommet, but it sounds like a real pain to deal with and might not work, either.

In "The Sailmaker's Apprentice", Marino hints that the placement of the brail line's cleat can make a difference, I presume due to changes in the friction created by routing the line's lower section in different ways. The favored method is to cleat-of the brail on the mast near the tack corner of the sail. Method #2 uses a block at the partners or mast base which routes the line aft to a cleat back near the sailor. While being obviously more convenient for single-handing, he states that this latter method can in some cases "spoil the sailshape". This is all he says about it, but about the only way that I could see it manifesting itself would be to create the type of problem that you are looking at. It might be worth playing with the cleat location to see if it makes a difference.

The brail line can only be lightened-up to a certain point before it's diameter becomes impractical, so you're limited there. It's weight and the system's friction is playing against the sail's leech tension. This, too is limited due to the lack of weight and stiffness that a boom would provide and the fact that mainsheet angle has a very definite affect on the sail's shape and can't be messed with very much without making a bigger problem.

I wondered about some kind of barberhauler or twing line-type gizmo (a block on a rope riding free on the lower part of the mainsheet) to temporarily adjust sheeting angle by pulling it forward to create more leech tension, but dismissed it as another control with a high P.I.T.A. factor needing constant attention. Like the batten, if it didn't instantly cure the problem, it wouldn't be worth the hassle.

This leaves the sail's leech as the only other variable that might be possible to play with. A firmer leech would tend to resist the line's efforts to deform it. Since the sail is cut vertically, there are no leech broadseams to adjust, so firmness can really only be generated by the amount of hollow cut into the leech. The "normal" amount of leech hollow built into a sail is around 1" for every 6' of leech length with the maximum depth of the curve placed about 45% of the way up from the clew. Since spritsails are loose-footed and boomless and leech tension is determined mostly by mainsheet angle, they are sometimes built with no leech hollow at all. You could lay the sail out next to a taut string and measure how much, if any hollow is built in. If there is minimal hollow, it should be possible to increase it which can help, though it may not completely cure the problem.

I cut the sail shown here with the normal amount of hollow and in light air it tends to do the same sort of thing, though maybe not as much. In this case, the boat is quite fast yet somewhat difficult to maneuver in tight quarters and the brail has to run back to the cockpit since the sailor can't move around much. We figured that the leech distortion sometimes caused by the brail was a decent trade-off for the ability to have a quick way to try to stop this boat when needed.
http://www.imagestation.com/picture/sraid28/p59565753615f802cdbc1de7a35ade329/fd6827ed.jpg

Sorry this answer is so long with so little meat in it, but I'm not sure anyone has come-up with a really great fix for the problem.

[ 09-26-2002, 02:33 PM: Message edited by: Todd Bradshaw ]

[htom]

A loop of 250 pound Spectra kite line, maybe, fed through an eyelet in the leech, for the brailing line? (You'd have to tie the end of that Specta to something more friendly to pull on, or wear gloves.)

[Ian McColgin]

A helium filled line so it floats?

The only one I ever sailed on just had the brail line long enough to let a huge bight sag down to the clew. Just took a bit of fussing when getting ready to brail up.

[Todd Bradshaw]

We also need to consider that the thinner the line is, the more damage it may do to the sail when it is pulled. It's quite possible to melt the surface of a piece of Dacron by pulling a line across it under load at high speed. I found this out once when lacing a lateen to the yard and quickly pulling large amounts of excess line through the grommets. These days, I always caution my customers to lace slowly, get everything in it's approximate position and then go back through and adjust or snug as needed. A brail line isn't much good if you have to baby it too much and I'm afraid that going to anything really thin may require that to prevent damaging the sail. Hey Jack, did you ever get the jib brail to work or did the idea just not pan-out?

[J. Dillon]

Todd,

Thanks for info.

Brailing is an essential part of my sailing. I need to depower the boat quickly when coming into my slip in a brisk wind. The below illustration halves the ammount of line to effect a complete brail.

By having the line from the leech join a single line, I eliminate the need for the brail line moving through the leech grommet or eye.

I did try brailing the jib but it was more trouble then it was worth. A slippery hitch serves well after leaving the dock and lowering the jib before I approach.

http://www.imagestation.com/picture/sraid33/p7ac378d62c9118cbb5a20835caa87c23/fd3afc53.jpg

Htom, Where does one get spectra kite line and what thickness is it available ?

Ian, Helimun filled line ? Hmmmmm

JD

[gert]

I have to ask cause I don't know.
Whats brailing?

[Donn]

Gert...that's how blind people read.

[Todd Bradshaw]

A brail is a small line that surrounds the top section of a spritsail or sometimes a boomless standing lug. The most common way to rig it is to deaden it at the throat corner of the sail or the mast right next to it, run it aft, across one side of the sail (outside of the sprit) and through a grommet part way down the leech (normally about as far down from the peak as the length of the sail's head - top edge). After passing through the grommet, it runs forward, across the other side of the sail to a block or fairlead on the mast and down to either a cleat on the lower mast or another block or fairlead at deck level which routes it back to a cleat in the cockpit.

Pulling the brail line squishes much of the sail and the sprit (or the yard on a lug) up against the mast in a bundle. It's an almost instant way to furl the sail - not the neatest furl possible, but very effective at stopping the boat from sailing. Likewise, you can have the sail rigged and brailed up against the mast when you launch and when the time is right, you release the tension on the brail and out pops the sail, ready to go.

Jack's is set-up a bit differently, but the idea is pretty much the same. His system uses fairleads on both sides of the sail and after surrounding the sail and passing through the fairleads at the throat, the two ends of the small brail line run down and are seized to a larger chunk of a line, part way down the mast and before you get to the turning block which brings the end back to the cockpit. Whether the extra weight of this heavier section is contributing to the problem here, I don't know, but I suppose it could. The advantage of rigging it like this is that there is significantly less chafe on the sail from the line while brailing.

A brailing system is also sometimes used on boomed standing lugs but it's a little different. It will run all the way down and under the boom, usually through a fairlead on the boom's underside. Pulling the line will quickly squish the sail, the yard and the now almost vertical boom up against the mast in a bundle. You have to have enough play in the gooseneck or boom jaws to allow for the normally horizontal boom to pivot up and lie alongside the mast and a mainsheet system that allows that much travel, but it can usually be done. Here again, the idea is to provide a method of furling or unfurling the sail, very fast, even if it's not particularly neat.

The last time I bought spectra kite string it was designated by it's breaking strength, like fishing line. The stuff I got was about the same diameter as the old kite string we had as kids (do kids still fly kites or do they have simulators on their computers?)It was 120 lb. test and a lovely shade of bright pink, though other weights and colors are available from places that sell stunt kites. Last time I saw it, my wife was using it as a guide for planting perfectly straight rows of beans. These places also sell Kevlar string, but buy the spectra as Kevlar is so abrasion resistant that it will cut through damned near anything.

With Jack's double fairlead system, the wear on the sail should be less and it might work. The question would be whether the upper brailing portion or the lower 1/4" line that it's seized to is providing the weight that's deforming the leech.

[John Bell]

Here's an idea that I don't know will work, but I'd be interested to hear what others think.

How about going to a single line tied to the leech and threaded through a couple of large grommets in the in the body of the sail, kind of like the old Dutchman flaking system? That way the weight of the brailing line would be better supported along it's length an less likely to interfere with sail shape. A modification of this idea might be to seize a couple of eyelets along the body of the sail to preserve the two-line system shown above.

JB

[J. Dillon]

Gert,

Todd explains brailing very well. In the image the brailing line is pulled tight, shown in the upper part of the sail. The lower portion is held in by a line passed around the sail and secured in my boat with a mating velcro strip sewn into a line lead aft to the helmsman. The upper line can be continusuly used to depower the boat or release if the sail needs to be re set. A nice option if you are losing steerageway when approaching a dock etc.

http://www.imagestation.com/picture/sraid33/p77b5ee59384ccbdf8a87808eb0e0a173/fd3abf70.jpg

John , Thats an interesting idea and it just might work. Lets hear what Todd thinks about it.

JD

[ 09-27-2002, 09:50 AM: Message edited by: J. Dillon ]

[Todd Bradshaw]

Off the top of my head I can't think of any good reason why it shouldn't work. The system weaving a single line through the grommets might have chafe or friction problems and the sections of sail being collapsed between grommets might flap since they aren't being surrounded by the line as it tightens, so I might opt for the double line system. The way I'd set it up is with a couple small diamond-shaped patches, like reef point patches to reinforce the grommet installation. Then I would seize two small thimbles together, through the grommets with one standing proud on each side of the sail and run the lines through them. It may or may not cure the problem at the leech and sort of seems like an awful lot of rigging to simply throw a rope around the top of the sail and sprit, but it might be worth trying.

[htom]

I wouldn't worry about Spectra kiteline binding, it's really slippery stuff. Hard to knot and have the knot stay; if you don't sleeve it you need at least three figure-8 knots along a loop, or more, to hold a loop reliably. I've seen stunt-kite flyers twisting three four line kites together in the air, wrapping a tight bundle of 12 strands of Spectra a half dozen times, and be able to pull one line in the bundle.

I've dealt with Into The Wind before; for the small quantity you'd need it might be cheaper to look for a local kite shop that could sell you 20' off a bulk spool they've bought. A local big hobby store might have it, too.

http://www.intothewind.com/cgi-bin/detail.cgi?itemnum=1788&sql=sli -- 275 pound bulk

You do have to be careful to get "pure Spectra", that is, line that's not a blend of Spectra and other fibers, or Spectra wrapped with some other fiber, or Spectra core in some other fiber. There are good reasons to use these other lines for one purpose or another, but for this I would think pure Spectra would be best. (And Todd's right, avoid Kevlar or Kevlar blends; that stuff can cut fabrics like a knife in these diameters.)

--

But if the problem is the weight of the 1/4" line pulling too hard on the sail, how about using a loop of 1/4", rather than seizing to the end? The loop's weight would be held by the sheeve, pulling down on both sides of the sheeve, and only the brailing line's weight would pull on the sail; it (the brailing line) would also go through the sheeve with the 1/4" loop when the sail was brailed. There might be problems in getting all three lines back through the sheeve when you tried to make sail, though. Two sheeves, one for the brailing lines, one for the loop?

[J. Dillon]

Todd,

Got another question. The sail posted about also seems to have a "memory", a negative one at that.
The curl shown in the first image returns even when no brail is stressing it. Is there any way of " pressing", steaming etc. or restoreing it to the original "memory" of built in fairness without minor surgery? The sail is 7 years old. Or has sail alzheimers set in ? :(

Thanks

JD

[Todd Bradshaw]

You could try ironing it in that area. Obviously, this needs to be done carefully as the melting point of Dacron is somewhere around 390 degrees if I remember accurately. Sometimes it will soften the resin enough to relax the problem and stay flat as it cools back down. I usually sandwich the sailcloth between a couple pieces of cotton about the weight of a bed sheet or T-shirt. You can use steam or a spray bottle to dampen things, but I don't know whether it really makes a difference compared to dry heat. The iron should be set on "synthetic" or whatever it has on the dial for things like nylon and polyester. If you have any scrap Dacron, it certainly doesn't hurt to do a test run to check the temperature.

Is there any way you can temporarily rig the mainsheet lead a couple inches farther forward for a test sail? I'm really starting to think that you might need more tension on the leech. I can see where the distortion caused by the brail line or the wrinkle left over from the brail on the cloth might show up in really light air, but by the time you get up to somewhere around 7-8 knots of wind, the leech should be under enough tension that they pretty much vanish.

[dadadata]

Maybe I missed Todd saying this but ---

someone, maybe Pete Culler or John Leather, says that the attachment point for the brail is determined by swinging an imaginary compass. The point is on the peak of the sail. The pencil is on the throat/nock.

Swing until pencil line intersects leech. That's where the grommet, thimble or block goes.

Can't tell from the photo but perhaps this is the cause of the problem.

[Todd Bradshaw]

Yeah, it's up there somewhere in the form of the brail being the same length down the leech as the length of the head. I don't know how Jack's brail is set up, but from what I've seen it doesn't seem to cure the problem. A sail's leech is a pretty fragile, largely unsupported shape. Look at how little stretch it takes to induce constant fluttering requiring excess application of the leechline or a minor re-cut to cure. Hanging a line on the leech just happens to often be enough weight and/or tension to deform it and especially on an old sail, the leech may not be firm enough to completely resist.

[J. Dillon]

Todd,

Re did the brail with lighter line ( about 3/32") and a smaller "tail" as well. smile.gif Also pressed out the crease and it all seems to help. :D Will experiment more before haul up time.

Can a resin be re introduced or "painted" on to stiffen just the leech in this portion of the sail ? :rolleyes:

Thanks

JD

[Todd Bradshaw]

I'm not aware of any good way to do it or of what you would use. The only re-resined sails that I've seen were three or four that had been to one of those sail "restoration" places where they strip off the old resin, bleach the living crap out of the fabric until it has all the integrity of an old T-shirt and then paint it with something. They come back very white, which is the only good thing that I can say about them. All of them came in because they had major shape problems, which the process either caused or failed to correct. If I was going to try to stiffen the area around the brail, I'd probably set in a fairly large half circle reinforcement patch along the leech. It doesn't weigh much and is the easiest way to get some stiffness back into the area.