The below maintenance guide was written by the late Robin Smith - first published on 31st January 1996 and still relevant 30 years later! The guide outlines key checks and easy repairs which can get boats back on the water quickly and easily! Whether you've just bought a boat or have been in the class for years, the below checks are a great way to get to know thre boat, and set yourself up with a fast, reliable platform!
The hulls are made from a combination of synthetic resin, glass fibre mat and foam, with some carbon fibre stringers. Should the hulls require any major repairs they should be returned to the manufacturer. Chips and scratches to the gelcoat can be repaired using the appropriate repair materials. In order to obtain colour matches it is advisable to obtain materials from the manufacturer.
General maintenance is limited to washing the grime off the hulls and then giving them a polish with a proprietary glass fibre polish. Beware of using polishes containing silicone, as this can be difficult to remove and may adversely affect any future repairs.
The centreboard slot gaskets can tear, or go out of shape with use. They are glued down with epoxy resin, so before a new gasket can be fitted, the old gasket must be completely removed, and all traces of the old resin taken off using gentle pressure with a sharp chisel. The surface should then be abraded with sandpaper to form a key for the new resin. It is a good idea to try and remove one of the old gaskets in one piece, to use as a template for the new ones. The gasket material, mylar, can be obtained from most good chandlers. The new gaskets should overlap each other by about 5mm for the open section of the box, and simply butt up to each other on the hulls at each end. If you did manage to pull one of the old gaskets off in one piece to use as a template, the new one should fit perfectly, otherwise you must cut the mylar material to fit the shape of the indentations in the hull. It is a good idea to establish the shape first on a piece of thin cardboard, then use this as a template.
The next stage is to mask off around the edges of the hull indentations with parcel tape. First do the length of the box, then stick short pieces straight across the ends, and finally use short pieces to fill the rounded corner sections front and back. Done carefully, this will avoid excess resin oozing out and sticking to the hull. Then apply the epoxy resin to the indentations in the hull. avoid going right up to the inside edge of the box. The theory here is that if the gasket is stuck right up to the edge, when the board is down the mylar will have an sharp right angle bend in it. This may encourage it either to crack, or start to lift off at this point. By keeping the resin back from the edge by about 5 to 7mm will produce a more curved bend, and hopefully result in a longer lasting repair.
Once the resin has been applied to one hull, stick the new gaskets in place, and then further secure it along the outer edges, and across both ends with more parcel tape. Obviously you will be sticking the parcel tape on to that already applied as masking tape. You then need to place a straight batten of wood, or a sail batten, or a strip of the rigid foam that is used for building the boats, along each gasket to apply pressure to the resin joint until it sets. These battens should be held down tightly by yet more parcel tape, which you apply by starting at the centre of the centreboard case, and going from one side to the other, holding down both battens, at six inch intervals. This tape should be applied by first sticking to one side of the hull, stretching the tape across the battens tightly and finally sticking down to the other side of the hull.
Everything should be left in place for several hours, preferably the next day, to make sure the resin has cured. If you do find any traces of resin have squeezed out on to the hull, they can be removed with a sharp chisel.
The centreboards are removed by lifting the hull up, such that the board can be pulled partially down. Then the board is pulled from above to pull the plastic tube swivel out of its locating slots. If the boards have not been removed for a period of time, they may require an initial sharp tug to get them moving. Beware also of damaging the sharp trailing edge of the board as it moves upwards, on the rear deck edge of the centreboard case.
Apart from repairing chips to the gelcoat, there is no maintenance required on the centreboards. Repairs to the lower tip of the boards, caused by grounding, are more easily and satisfactorily effected by using one of the marine filler pastes available. These materials set quickly, are easily shaped with a file and wet and dry paper.
The mast requires minimal maintenance. This is limited to checking the attachments for the shrouds, forestay, trapeze wires, spreaders and diamond wires. Make sure all securing split pins are in place, and taped up. Where it is difficult to tape them up, particularly rings, a blob of Araldite will seal them, and it can still be chipped of with a blade should future removal be necessary.
The spreader adjusting bottlescrew can occasionally be sprayed with one of the maintenance sprays, such as WD80, ( twice as good as WD40, but difficult to find in Halfords) but take care here, because some bottlescrews seem to undo themselves quite easily whilst sailing. If yours does this, I would advise against further lubrication. Incidentally, if your bottlescrew does insist on unwinding itself, a potentially mast breaking situation should it completely undo, the answer is to fit a suitable shackle through it to stop it turning. Tie the shackle on to something to prevent loosing it if you have to take it off to adjust the bottlescrew whilst sailing.
A light smear of one of the synthetic waterproof greases, such as Turbolube, can be occasionally applied to mast ball, but sparingly please, as excess tends to get wiped off on the jib sheets. The main halyard, and the rollers in the top and bottom sheaves should be checked for wear.
All of these are pre-stretched when new, although they will all settle in after a few sails. The shrouds should occasionally be checked for length against each other, but more importantly all the wires should be checked for broken strands. If a broken strand is found, replace the wire immediately. Failure is imminent. If you have to sail to complete a race series, fine, but please do not turn up the following weekend without a new wire.
A word here about the shroud adjusters. Most people un-tension the rig after sailing by moving one shroud up to the top of the adjuster, re-tensioning before the next sail. NEVER NEVER go sailing without the shroud adjuster clevis pins and rings properly secured with insulating tape. If you never tape them up you will definitely loose your mast, you are an accident waiting to happen. If you usually tape them up, but forget just once, this is the day when your jib sheets will foul the ring, pull it off and yes, you’ve guessed the rest. IT’S CALLED SOD’S LAW. DON’T FALL VICTIM TO IT!
The boom is often neglected when maintenance is on the agenda, but at your peril! If you suspect the shockcord that returns the clew outhaul is weak you can tighten it quite simply. Unbolt the forward boom cast fitting. You will see that the shock-cord is hooked over a stainless hook rivetted to one inner wall. First, loop a length of line through the shock-cord. This serves two purposes. Firstly you can now pull the shock-cord loop out of the end of the boom and shorten it. Do this by simply tying a knot in it, without cutting the excess off. This way if you find you have overdone it , you can make another adjustment. Secondly, if you accidentally let the shock-cord go, you can retrieve it with the line looped through it.
If the shock-cord needs replacing at any time, the first stage is as per above, but tie a couple of metres of line on the shock-cord. You can then release the tension by letting it retract into the boom. The next stage is to undo the aft boom end plate, and carefully remove it. Take the small retaining split pin out of the clew outhaul plate on top of the boom, and then push the plate into the boom at the same time as pulling the inner traveller out of the boom. Once out of the boom you will find all the wheels fall off the traveller as there are no retaining pins, so do the whole thing carefully, and make a note of where everything comes from.
Re-assemble in the reverse order, as the saying goes, and don’t forget to pull the new shock-cord through to the forward end, securing it over its hook, and finally replace the forward end of the boom, and put the split pin back in the clew plate to prevent it inadvertently dropping inside at some inopportune moment.
The trampoline should last for a number of years if a little care is taken with it. It should be rinsed off with fresh water if possible after sea sailing, but the singular most important thing is always to protect it from ultra violet rays when not in use. A simple cover with adequate securing lines will be pay for itself many times over. Just check on the price of a replacement trampoline. A properly protected one should last for at least five or six years with little maintenance, whilst I have seen neglected tramps looking in a very sorry state, and requiring major repair after eighteen months. If you have a good fitting cover you can even tow with it on, but make sure it is properly tied down, and no flapping parts can chafe the hulls.
The tensioning cord holding the trampoline to the rear beam should occasionally be checked for wear. The cords holding the toe straps to the rear beam need a cursory glance before every sail. They seem very prone to chafing through, and seem to have a special nack of undoing themselves, no matter how tightly the knots are tied. I prefer to wrap insulating tape around the cords and knots to prevent them working loose, but leave the aft end where they secure through the rear beam eyelet uncovered so they can be inspected visually.
The rudders consist of two major parts, the blades and the stocks. The blades are likely to be damaged by any high speed impact with a stony bottom, and if the kick-up/ lock down mechanism is adjusted incorrectly, the damage may be severe and may also extend to the stocks themselves.
Repairing a Rudder Blade
Firstly the easy option, repairing a damaged blade tip. The correct material to use for a minor repair is of course gelcoat. As with the centreboards, I never use gelcoat, for a number of reasons. It is difficult to work with to get a good repair and original shape back into the thin tip of the blade, it takes too long to dry, and the resultant repair is usually too brittle, and soon breaks again.
Instead I use a product in the Plastic Padding range, called Marine Filler. This is a material very similar to Plastic Padding, which dries to a light grey/green colour. It is very easy to work with, dries in a few minutes, and can be easily sanded or filed back into the original shape in a few seconds. It can be perfected with fine grade wet and dry and the finished repair, whilst not exactly the same colour as the original silver grey, doesn’t look horrendous. (Yes, I know Huw, there’s always one exception!) It also has the big advantage that big repairs can be undertaken with one mixing, where as gelcoat requires building up in several thin coats.
Whilst on the subject of re-shaping, most D.I.Y. stores sell a range of hand sanders made by Sandvik. These usually take the form of an orange plastic hand grip, on to which sticks a metallic abrasive pad. The medium one in the range is excellent for getting the initial shape back, before using wet and dry. I advise getting the correct rounded shape back first by sanding only the bottom edge, moving the sander from the good front edge to the good back edge. When this has been achieved, then tackle the sides with the Sandvik, before finishing with wet and dry. You will find it is very easy to repair blades using this method between races, and most people who sail at Marconi Sailing Club at low water become very good at it!
Sorting the Stocks
The stock consists of two parts. The blade retaining part which fixes on the transom, and the lifting tiller arm. The tiller arm has a bolt at the rear end which locates through a nylon bush in the top rear of the blade, and the bolt hole in the tiller is in fact a slot, allowing for adjustment. Underneath the tiller arm is a stainless bracket supporting a roller. This roller should be free to revolve on its axle and should be kept lubricated to make sure it doesn’t seize. This whole bracket can be distorted by hard collisions with the bottom, where the rudders have not lifted. If you cannot adjust the blades correctly, check the shape of the roller with the other rudder, or with a new one. They are difficult to repair, the best remedy is to replace it.
The stock itself has a spring loaded cam near the top, which grabs the roller when the rudders are down. The tension on the spring can be adjusted by a stainless steel allen screw located just behind the top pintle, and locked with a nut. In older boats the lock nut is usually superfluous as the stainless screw will be seized into the stock by a chemical reaction between the two metals. The lesson here is to take them out periodically and lubricate them with copperslip or a similar anti-seize compound.
Adjusting the Rudders
So what are the common rudder problems?
Rudders do not lift on contact with foreign object... this is caused either by an incorrectly adjusted cam mechanism, or because the roller under the tiller arm has seized.
Rudders lift too easily, i.e. water pressure on a reach... this is always because the cam mechanism is breaking away too soon, i.e. needs adjusting.
The Boat has too much weather helm... this is usually because the rudders have free play fore and aft and is usually as a result of running aground without the rudders lifting. This moves the tiller arm pivot bolt, or bends the cam roller under the tiller arm. To check rudder free play, lift the sterns of the boat so that the rudders can be fitted in the locked down position. Now stand behind each rudder and first push the blade forward, then see how much you can pull it back before resistance is felt. If it moves at all it is bad news! If it moves more than a centimetre at the tip you will be experiencing weather helm induced by the rudders, not the rig. To demonstrate the way some people are oblivious to this problem, we have had boats turn up at our training weekends with three or four centimetres of backward movement!
First eliminate free play. Lift the sterns of the boat, fit the rudders, and lock down. If you have free play then you will need first to lift the tiller arm out of it’s locked down position, but keep the blade itself down. Next, slacken the tiller arm fixing bolt at the rear of the arm, and please use two 10mm ring spanners, not mole grips. You should now be able to slide the tiller arm backwards and forwards as the bolt moves in the slot.
Stand behind the rudder and push the blade hard forward with one of your legs. Now hold the tiller arm just above the stock and pull it forward as far as it will go. Now, whilst holding it hard forward, lower it into the top of the stock. As you lower, the stainless roller should run down the upright face of the stock immediately in front of the cam, and at the same time, push the cam backwards, until finally it grabs over the roller, and locks it down.
The first problem that may be encountered is that the tiller arm cannot be pulled far enough forward to displace the cam backwards. Check first that the securing bolt is fully released. and that the tiller arm is pulled right to the front of the slot. If all this is O.K. then the roller assembly is bent and the only answer is to obtain a new one, bolt it under the arm and start again.
In order to achieve a really play-free set up you need to tighten the locking bolt at the rear of the tiller arm just before the cam fully grabs the roller. I would advise to get someone to help with the operation until you have mastered it. Firstly pass your helper the spanners. Next, place one hand at the front of the stock near the top pintle, with your fingers pointing upwards on one side and thumb pointing upwards on the other. Remembering to keep the rudder blade pushed hard forward with your leg, grip the sides of the stock with your fingers and thumb in such a way that as the tiller arm is lowered with the other hand, you can check its downward movement into the cam with your finger and thumb tips.
If you practise this a few times you will find there is a definite point at which the cam grabs the roller and the tiller arm locks fully home. The object is to hold the arm with your finger and thumb tips at a point when the cam is pulling roller down, but not fully locked. Now ask your helper to do the locking bolt up tight. If you have got it right, you should, looking from the side of the stock, be able to see a gap of about two or three millimetres under the roller.
Now, check the locking nut and bolt are really tight, and then knock the tiller arm up to release it, before dropping it back down again with some gusto so you hear a good solid click as the cam engages. Now the moment of truth, check the freeplay again. Hey presto! Nothing at all.
Adjusting Kick up Pressure
For this operation you will need a fairly large screwdriver, an Allen key to adjust the screw adjuster, a spanner to undo and tighten the locknut. and finally a medium size round file. Firstly undo the locknut and make sure the adjuster is free. It is a good idea to treat it with an anti seize compound, like Copper Slip at this stage. When you back the adjuster off, be careful that the stainless spring under the cam does not fall out. (Don’t be alarmed if it does, just pop it back. The important thing is not to lose it)
The next thing to understand is that the springs are not all the same length. I am told they are made by cutting a long spring into little pieces, not exactly an exact science! Now, put the rudder assembly on the boat again, but do not engage the tiller arm into the locked down position, and wind the adjuster back in about half way. Lock the tiller arm down and then stand behind the rudder and test the kick up breakaway by pulling backwards. If it is too easy, continue to wind in the adjuster until a point is reached when the kick up feels right. At this point hold the adjuster in that position and tighten the locknut.
The more astute reader will have noticed that we haven’t yet used all the tools I suggested might be needed. It may be found that even with the adjuster wound right in, not enough tension can be put on the cam to hold it. This is where the round file comes in. Try to see where the cam sits on the roller, and take a few rubs with the file at this point, towards the tip of the cam, making the curve at this point slightly deeper. DON’T OVERDO IT! Just two or three good rubs may be enough, then try it and if the rudder still breaks too easily, take a touch more off.
When you get it about right, you will find that the adjuster will actually start to do something, and you should be able to use it to fine tune the kick up. You may have noticed the screwdriver still has not been used. If too much curve is filed into the cam, it will be impossible to lift the tiller arm, even with the adjuster fully unscrewed without breaking something. If this happens use the screwdriver to poke in the back of the stock, under the tiller arm and trip the cam. You will then need to flatten off the curve a little with the file again to redress the situation.
Tiller Arm Pins
Another potential rudder problem is fatigue of the stainless steel pins which connect the tiller cross bar to the tiller arms. These pins take quite a lot of strain in heavy steering manoeuvres, particularly if not properly aligned, and the pressure can be enough to bend the pins, eventually causing them to shear off.
To check alignment, once again lift the sterns of the boat and fit the rudders in the locked down position. Firstly, visually check the pins to see if they are vertical to the rudder blade. You can also use the horizontal line of the rear beam to line them up. Next fit the tiller cross bar. Move the rudders from side to side slowly. If the movement is stiff on one side or the other it is a good indication that the pins are out of line. As the rudders are moved from side to side, the tiller cross bar may be bending one pin to line up with the other, and this is what will eventually cause fatigue and failure. If a pin is detected out of line, the only way to straighten it out is with brute force. Wrap a piece of cloth around the tiller arm next to the pin and grip it with a pair of large mole grips, or a pipe wrench. Then by trial and error twist it until it is straight. The result should be a totally free moving system.
Rudder Alignment
The last remaining task is to check rudder alignment. That is toe in or out to the motor mechanics amongst you. Mark the exact centre of the leading edge of each rudder blade at the same height just under the transom with a marker pen. A colleague is needed to hold the other end of a steel tape measure. First check the leading edge measurement. This only needs to be done once, as it will not change. Compare this to the trailing edge at the same height. If adjustment is needed, use the threaded screw in one end of the tiller cross bar. It should be possible to achieve exactly the same measurement for both rudders. If the screw is wound in as far as it will go, and more adjustment is needed, it is possible to cut a centimetre or so off the tiller cross bar. At the same time as you do this, check the depth of the hole remaining against the length of the screw thread, which may need shortening slightly to prevent it bottoming out.
The mainsail is made of a mylar laminate, and requires only a wipe with a damp cloth to remove marks and dirt. Regular checks should be made on the seams, particularly on the top two or three panels to check for stitching pulling through the material. This problem should not occur on sails made after September 1993, as the seams are now all double stitched, and much more durable.
Also check the headboard rivets for corrosion on older sails. I would recommend having them renewed, regardless of visual condition, on a sail older than three years. The mainsail is normally stored rolled with the battens fully tensioned. Battens should be checked on a regular basis for tension.
The jib is made from dacron, and should be dry before it is rolled for storage. The jib luff should be checked for wear and tears caused by friction with the forestay. Small tears and areas of wear can be repaired by sticking self adhesive sail repair tape inside the luff tube. The zip should be checked for missing teeth. One is probably acceptable, but any more and a trip to the dentists may be necessary. It has become general practice to obtain a length of plastic drain pipe to roll the jib around for storage. This prevents creasing and flattening. Clips and shock cord can be added to the pipe to secure the foot of the jib.
The only adjustable part of the beams is the dolphin striker on the main beam. This should be adjusted so the beam is just under tension upwards. The best way to assess this is to sight along the upper rear edge of the beam from one side of the boat to the other. The upper edge of the trampoline slot provides a good straight edge. Do this check with the mast off the boat. Ideally you should be looking for an upward curve in the centre of around 5mm. To adjust it just wind that big nut at the bottom of the dolphin striker tube. This is an oft neglected, but important adjustment. A sloppy beam is SLOW!
Beam Bolts
The beam bolts screw into threaded plates built into the hulls. If my memory serves me correctly, the plates were made of aluminium up to about sail number 180. The later boats have plates made from a bronze alloy. Aluminium is not the best material to screw a stainless bolt through, as these two metals set off a chemical reaction which corrodes the aluminium, seizing the two together. If you have an older boat and can still get the bolts out, do so, and give them a good coating of Duralac, and do this at three monthly intervals. If you have a newer boat, it is still a good idea to take the bolts out once a year, and treat them as well.
Helicoils
If you are unfortunate enough to strip a thread, more likely with the old aluminium plates, this can be easily repaired using a device called a Helicoil. A Helicoil kit is quite expensive. For this you get 10 Helicoils, a thread tap, and an insertion I tool. Of course you will be hard to pushed to find a Helicoil kit on the shelf at Tescos. Grab I Yellow Pages and look under “Fixings and fastenings”, and then let your fingers do the walking.
The kit I have is Australian, and called “RECOIL”. The size needed is M10 X 1.5, and I the part number is 35100. You also need to buy a metal drill bit, size 10.4mm or 13/32.
The first step is to take the beam off the hull to reveal the bolt hole. Run the drill through, taking care to keep the bit in the same upright plane as the bolt. If it’s a front beam bolt you are working on you can partially screw the other beam bolt in as a guide. If it’s a back one, good luck!
Next, screw the tap in, once again trying to follow the original bolt angle, and keep working the tap in and out until it screws all tl~way through smoothly. Next fit the Helicoil to the tool. The bottom of the Helicoil has a bar across it and the tool has a slot in which this bar locates enabling it to be screwed in. Screw the Helicoil in until the top is about half a turn below the surface, and then pull the tool up to disengage the bar, turn it 90 degrees and push it back through the Helicoil until it rests on the bar, then give it a smart tap with a hammer, which should break the bar off, and lock the Helicoil in place. Job done!
The first one is the worst, especially if it’s someone else’s boat, and the owner is watching! After that you’ll be entering the “How many Helicoils can be fitted in a minute” competition.
Traveller
The traveller should be rinsed with fresh water after sailing on the sea to remove salt and sand. Do not oil or grease the roller bearings, as they will pick up grit and wear out more quickly. The angle of the jammer plate, and tightness of the swivel bolt should be checked, as a loose plate will make jamming more difficult.
The blocks contain ball bearings and should be rinsed with fresh water periodically to remove salt and grit. As with the traveller, do not lubricate these bearings.
Still looking for some extra guidance, or for an experience pair of hands to carry out work on your boat? Andy Webb at AW Sailboats is a Hurricane National Champion, experienced boatbuilder and long-standing supporter of the class. Get in touch with Andy who will be happy to help!