PROBLEMS TO DO WITH THE RIG EFFECTING SAIL SHAPE
INMAST FURLING MAINSAILS
Most inmast systems have a means of tensioning the foil inside the mast, this is important as if the foil (the cable inside the foil) is not tight enough the foil turns through an arc rather than turning like a rod, this dramatically increases resistance to furling as the load on the sail starts to pull the foil through the mast opening. adjustment is by tightening a lock nut either below the winch unit inside the mast or at the masthead. this is best left to a rigger.
to set the boom height with a the topping lift or solid kicking strap ,hoist the mainsail tight so all horizontal creases are gone and the outhaul pulled so the sail is as flat as possible , then with the topping lift or solid kicker adjust the boom height so the sail has a small amount of twist and the upper part of the leach is parallel to the centre line of the yacht and not curved up to windward, this set up prevents the leach being pulled down as it is furled and jamming, battened leach inmast furling mainsails can be set with quite large amounts of twist.
FURLING GENOAS
Forestay tension controls the sail shape and allows the foil to rotate easily with minimum resistance, tight backstay and shrouds controls the forestay tension.
A loss of pointing and overfull sail shape as wind increases are the usual indicators of lack of tension, when supplying new sails we advise on rig setup to optimise the performance of the sails.
SHEETING POSITIONS
Unlike the pure racing yachts, Cruiser/racers have a wide shroud base and long spreaders to support the mast better and often limited size tracks to sheet the genoa on. So it is vital the genoa all through its furled range sheets correctly, sailing upwind it is normal to have the leach about 4 inches of the spreader end and the foot touching the shroud base, this brings the genoas sheeting angle as close as possible to the mast for best pointing, if you cannot achieve this you will have to look at rig/sail adjustment
SLIDE FIT PROBLEMS
There are more than 20 popular luff slides in use (excluding fully battened sail roller slides), however most Kemp/Selden masts take only 1 or 2 types.
The slides are made from nylon and stainless steel covered nylon with steel or alloy used for the highly loaded headboard slide.
A mast will work best with its designed slide but will " sort of" work with some other slides fitted by mistake,
The correct fit is a loose sliding fit with no trip jamming when slide is rocked sideways or up and down. a flat plate type slide will have greater friction than a slug type slide.
Difficulty in hoisting and lowering mainsail
Check the masthead sheave is revolving as these are often seized solid, try tensioning a halyard against your own pull without a sail attached you will feel if its moving.
Fully battened mainsails except on small yachts require special compression roller slides to be fitted (see fully battened main in cruising sails section).
check slide attachment to sail is a loose fit and that slide shackles or webbings are not to tight.
PTFE spray or silicon spray can be used in the track but never use any grease as this traps salt and acts as an abrasive.
Check all slides including head board are the same offset from the luff boltrope top to bottom.
Look how the slide is worn to indicate where mismatch occurs .
Difficulty in reefing because slides get in the way
If a slide is positioned to near a reef cringle problems can arise placing the cringle on its reef hook ,the minimum distance for the slide is 40 to 50 cm above and 20 to 25 cm below the cringle. slide positions are fairly easy to move.
Slides stack to high when sail is dropped
slide spacing except near a reef is 75 to 90 cm this allows the sail to flake either side of the boom yet control the sail shape near the mast, (fully battened sails will often only have 1 slide between each batten car.) increasing slide space will reduce dropped height by each slide removed.
chattering or vibrating slides
This can be caused by a slack boltrope not supporting the luff of the sail or lack of halyard tension, otherwise check that slide distance from boltrope is the same with all slides ( all slide shackles are the same length).
If the mast bend curve does not match the sails luff curve the difference will produce local areas of slack and tightness ,look for any creases as these will point to where the problem is.
CHAFE PROTECTION FOR SAILS
prevention being better than cure, look for the sources of sail damage. for the genoa , the mast spreader ends and forward stanchion tops are the first place but don't forget the radar and where the foot rides up over the life lines, you cant easily cover these last items so the sail should have a protection patch if there is a problem.
baby stays and forward facing lower shrouds should have roller tube fitted to allow the sails to slide over them.
cutter rig yachts have a problem with the genoa sheet and clew ring being dragged around the often furled staysail, a heavy duty patch has to be sewn onto the uv guard a few feet up the staysail leach
large overlapping genoas often hang up on the spreader end even if the end has been protected, this is caused by the leach area becoming dished by the impact when the sail flaps its way through a tack, often the best cure is to remove and replace the dished fabric.
On the mainsail look for batten pocket damage from badly tied down reefs and runners picking up the inboard batten ends. and with swept aft spreaders those ends again, you might need a further patch for when the sail is reefed.
there are several materials for wrapping the spreader ends etc from the pvc mouldings available from chandlers to hand sewn leather.
Leather has rather gone out of use as the quality has dropped and rotting has become a problem.
PVC (insulating) tape works but you need a lot of it wrapped around, it tends to go brittle in sunlight.
duck tape is ok but can be abrasive when worn and is difficult to get off.
Racket ( bike handlebar) tape ,probably the best but do not choose red as the colour can run.
Dacron insignia fabric, this sticky back material with a peel paper is the fabric sail makers use for reinforcing racing sails as well as making sail numbers, although not as strong as normal weight sail cloth, it can be used for spreader patches on the sails as long as the surface is clean and dry, no stitching is required , this is not the stuff sold in chandlers as spinnaker repair tape which is not so sticky or strong.
2 inch dacron webbing can be used usefully instead of leather ,raw edges are heat sealed the material is easily hand sewn, good for long distance sailing.
Cable ties are a mixed blessing they are easy to fit and hold protection in place but are highly abrasive especially when cut , so use carefully.
Spinnakers
Sharp beaked seagulls have often caught the blame for spinnaker damage but in actual fact foot damage is often caused by the spinnaker pole end fittings wearing to a sharp edge or a clevis pin on the under side of the boom with hatch take downs.
damage local to the top few feet at the head is often the furling gear top swivel shackle or a wire halyard that's catching the sail.
If the tears are small , dacron insignia cloth can be stuck on, align fabric tear so its flat, clean and dry surface before applying fabric.
silicon based spinnaker cloths as used on many one design and sports boats will not take insignia cloth because the glue wont stick,
all is not lost as clear silicon sealer can be used with a piece of the original fabric, allow an inch overlap and 10 minutes to dry.
Some snuffers have a mouth made from GRP ,these crack when bounced against the mast and tear the sail as the snuffer is drawn down over the spinnaker.
the damage will not be seen until the next time the sail is used.
GENOA LUFF TAPES
Racing headfoils made from plastic like Tuffluff are a one piece extrusion and are prone to wear just obove the feeder unit, this is often caused by the halyard crew not being smooth enough ( watch the halyard being jumped at the mast).
Jamming on hoisting can be caused by a badly placed prefeeder or incorrect size luff tape ,often the best place for the prefeeder is halfway between deck and feeder unit and about 10 to 30 cm aft of forestay, the luff tape bead diameter should be at least 2mm greater than the foil opening or gap and at least 2mm less in diameter than the bore of the foil groove.
To clean a foil hoist a short piece off luff tape (from your sailmaker) soaked in PTFE or silicon dry lubricant , if the foil system has sections you will feel the tape being gripped by any misalignment of the sections (check the join sleeve and fastenings if this is a problem.
When using a roller furling system as a race foil check that your genoa luff tapes have a second smaller bead rope about 15mm behind the front bead this helps the passage of the sail through both feeders and the foil. the feeder units on furling systems are not as efficient as racing headfoils because of the foil extending down to the drum and only allowing an angled feed.
Luff tape repairs can be difficult if the bead rope is broken as any splicing will increase its diameter, in this case the entire length of luff tape has to be replaced, if the fabric covering the bead rope is damaged an outer sleeve can be tightly fitted but its larger diameter has to be an easy fit in the foil bore, sticky back dacron insignia fabric can be used as a temporary repair but the damaged section will have to be clean and dry for the adhesive to work.
mark the repaired luff area with a felt pen so the halyard crew know where a jam is more likely to occur.
