If you had to come here for this information,
and you didn't buy the sail from us,
you have to ask yourself 2 questions.
Why didn't my dealer tell me this? and Why did I buy my sail from him?
Sunfish Racing Sail Bending On and Tuning Guide
Copyright 2002 Daniel Feldman / Wind Line Sails
This work may not be copied or redistributed in any form without permission.
Find a clean area big enough to lay out your new sail and spars. Spread out your spars and lay the sail between them. The tack (the corner with the label on it) should be placed at eye bolts where the 2 spars meet.
While the spars are bare it is an ideal time to add measurement marks for both the halyard and the gooseneck. Below are the measurements I use. All measurements are made from the seam where the aluminum meets the end caps.
Halyard: From the top of the gaff I mark 2 positions. The first is the standard racing positions which is 54" below the top of the gaff. The second is for either rigging a Jens in heavy weather or for day sailing where you might want the boom off the deck and it is at 74". Lighter sailors who use a "short Jens" may want to mark a 3rd position mid-way between the 2. I then add half a dozen wraps of white electrical tape at these marks. It is important that you use white electrical tape. Black, coloured tapes or duct tape will get hot in the sun and slide leaving a sticky mess on the spar and halyard.
Gooseneck: Marks every inch between 14" and 24" back from the front of the boom. In general, you will sail using a range between 15 and 20" using the halyard in itís normal position and from 19 Ė 24" when the Jens is rigged.
If you do not have an outhual or cunningham rigged this is the time to do it!
The first thing I do is attach the tack of the sail to the eyebolts using the stainless steel hook. (There has been some talk about whether to use the hook or to attach the tack by binding it with Kev cord or another super low stretch cord. I have never had a hook fail. The only down side to it is if you are constantly removing the sail. It also does not stretch or chafe through.) Tie the clew to the boom end cap temporarily under just enough tension to stretch most of the wrinkles out, but not tight. Now itís time to make the most critical of the adjustments. The head must be tied to the cap at the top of the gaff. This is where most people goof. The tension on the head is absolutely critical. Tie about 18" of low stretch line to the head of the sail and lead it through the eye on the end cap. Lift the top end of the gaff off the floor. Tension the luff until it draws up to form a nice smooth curve with the luff hanging just under the gaff. It should not be drawn any tighter than is needed to achieve this. There is some debate about whether to use sail clips or ties. I use 6 or 7 ties per sail and clips for the rest. I use ties at the head of the sail, the cunningham grommet and the 2 eyes above and below where the halyard attaches. The ties should hold the sail where the clips would with about an inch of space between the tape and the boom. I use ties on the boom at the first grommet behind the gooseneck which facilitates changing on the water if needed and also at the clew. If necessary I will also add ties to any grommets that interfere with my boom blocks, tying the grommet loose enough that it can still move as the outhaul is adjusted.
Once the sail is on the spars it is time to check it out. With the boat on the beach or on a dolly put the rig up and hoist the sail. Make sure there is not so much wind that the boat will get blown over.
With the rig up I add my telltales. I like to use only one set of tells. I mentally draw a line from the head of the sail to a point about 40% aft along the foot. I then reach up about 4í above the boom and put my tell tales at this point. With the sail in trim the leeward tell will be just slightly stalled. Why here? Good question. Any further toward the luff and bad air from the spars will affect the air flow, especially on port tack. Any higher up and I have to look away from the water to see them. Why not more sets. Well if you would like you can follow the line up a couple of more feet and put another set, but it wonít help. You have almost no control over the leech in a Sunfish and as a result all you need do is over trim the sail slightly to allow for the twist you canít control anyway. Some people like a set on the leech as well. Just remember that the only time they will be any help is running by the lee to check air flow.
With the tells on sheet your sail in until it is close hauled on stbd tack. If the uphaul is correctly adjusted, you should see a nice series of scallops along the luff of the sail. The tighter you sheet, the bigger they will appear. This is FAST! A wrinkle free luff is only fast in very heavy air and smooth water. To help take the wrinkles out you will use your cunningham as the air gets heavier. The scallops should never get so big that they start getting out to leeward of the boom. If you donít see the scallops, drop the rig and ease the uphaul. Unless they are obviously to loose, try sailing before tightening uphaul. Most sailors sail with the uphaul WAY to tight. Last. Sails are generally cut to allow for some stretch. It is always a good idea to sail with a new sail for a few hours before a big regatta in moderate air. You may find that you need to take up on the uphaul a little bit after the first few sails to compensate for this stretching.
Outhaul adjustment: As a general rule people also tend to over tighten the outhaul up wind. The current racing sail performs best in light and medium air with the outhaul eased enough to open the shelf. If you need to point for a short period of time ie. to lee bow a boat on your hip, tighten it slightly and then ease it again when you have snuffed him off. This sail will deliver the best VMG if you allow it to develop full power. As you turn on to the reach legs ease it enough to put medium size scallops in it.
If you are making the transition from a non-racing sail, you will find that the racing sail does not allow you to point quite as high. However the boat will gain more than enough speed to make up for this. So donít fight it. Foot and let the sail do itsí thing. You will also find that it is more responsive to tension on the luff and foot and bigger gains can be made from the correct setup.
If you still have questions, they should be directed to:firstname.lastname@example.org or I can be reached in my shop between 10am and 11pm most days 847-579-9223