Guest guest Posted January 20, 2004 Posted January 20, 2004 At the outfitting workshop this past weekend, we saw rope skeg systems under repair. The problems we found and the fixes in each case may be of use to others. The design is the one found on Valley and NDK boats (though both manufacturers have switched to cable skegs for most boats).First, some basic principles. The skeg blade itself has a hole thatpivots around an axle. The blade is held on the axle by a pair ofthin disc-like hubs that are press fit onto the axle on either sideof the blade. The ends of the axle are inserted into the shallowchannels in the sides of the skeg box and slide up into the box. Thehubs that surrounds the axel provides an attachment point for thebungie which comes down the tube at the top of the skeg box, wrapsaround the hub on one side, goes through a hole and wraps halfwayaround the hub on the other side and returns up the tube. Theleverage of the bungies around the hub is what rotates the skeg. A line (the rope) is attached to the blade, runs up through the tube in the deck, goes through a small pulley and then to a jam cleat mounted on the deck near the cockpit.The skeg should slide in and out of the skeg box fairly easily by pulling on the skeg blade when in the down position. The channels in the box align the axle in the proper position. The only thing keeping it in the box is the bungie tension and, when cleated, the line. If the skeg does not come out easily, it indicates a problem, usually amismatch in tolerances between the box, the axle, the hubs and theskeg blade itself. All of these can be adjusted. It is important that you can get the skeg in and out easily; it was designed that way to make it easy to unjam the blade and to do field repairs.The skeg should also raise and lower easily with minimal resistanceor sticking. If it does not snap up and down effortlessly, it can usually be fixed, albeit with tinkering. Don't settle for a sticky skeg!What we found:One NDK Explorer had always had a very sticky skeg. When wetried to pull it out of the box, it stuck halfway and four stronghands with feet on the hull couldn't budge it. Leverage finally didthe trick. The fix was to grind the ends of the axle on a power drum sander: essentially the axle was too long (or the skeg box too narrow). Less than a 1/16" or so on each side did the trick.A second problem with this same boat was that the hubs had beenpressed together and were pinching the blade. So we had to pry thehubs apart a bit to provide more room for the skeg to pivot aroundthe axle. When fixed, the skeg slid in and out of the box easilyand also pivoted easily.Another Explorer had a skeg that went in and out easily, but did notpivot well. The hubs were at the proper tolerance. The solution wasto pry the hubs off the axle (gently) and enlarge the hole in theskeg blade with sandpaper. A little sanding with fine paper wasalso done on the axle to clean it up, but too much of thatand the hubs would no longer fit snugly on the axle.Overall, there are several tolerances that need to be correct: theskeg blade hole around the axle (loose enough to pivot freely), thepress fit of the hubs onto the axel (tight enough not to move butloose enough to adjust), the slight spacing between the hubs and theblade (wide enough to allow free skeg rotation but close enough tokeep the skeg in line) and finally the axle fit in the channel in thesides of the box (free to slide in and out but with little play).Generally, we found it easier to alter the skeg components than theskeg box. A power drum sander (both hand drill and drill press) wasused to grind the end of the axle, but hand sanding was needed forthe tight tolerances. Sometimes, the skeg box itself is theproblem (crooked, too tight, out of alignment), but we didn'tfind anything during the workshop we couldn't fix by adjusting theskeg assembly.Some use lubricants on the axle, hubs and in the box to make the skeg move smoothly. Silicone or other high tech lubes do work, but can attract grit and gummy crud. In principle, lubes should not be necessary given the design: the only surfaces that should touch are the inside of the skeg blade hole against the axle and this need not be a tight tolerance. If lubricants are a necessity, you may have some other problems. In particular, the hubs can get too tightly pressed against the blade. Simply pull the assembly out of the box andgently pry the hubs away from the blade slightly.Rope skegs may do better after being re-rigged with heavier lineand bungie. Many find the original NDK rope too thin and it appears tobe a nylon braid, which stretches. I've found a polyester coreline to give more positive control. Lines and bungies that are too thick begin to bind in the tube down through the deck. A stiff rope has the same problem: it doesn't run smoothly around the pulley anddown the tube.Another binding problem in the tube is the result of line beingpinched by the bungie. Aside from getting the right diameter, putthe bungies in first and then take care to thread the line where itwon't bind.If that doesn't fix the binding, check the tube itself. Thestock NDK design has a fiberglass tube or nipple projecting up fromthe skeg box and down from the deck. A short length of plastictubing bridges the gap and is fixed in place with a hose clamp oneither end to waterproof the stern compartment. After 3 seasons ofsticky skeg problems on my Romany 16, I discovered that the tube hadbeen kinked at the factory, pinching the skeg line. (The tube was abit too long or had not been fully pushed onto both fiberglass tubes,so it squished together like an hourglass in the middle.) In fact,it was tight enough not only to bind the skeg rope, but forced theline to almost cut through the plastic wall. I replaced the plastictube with a heavy clear vinyl tube which solved the problem. Theinstallation can be tricky as there is only about 1-1/2"separating the ends of the respective fiberglass tubes and it'stough to get both ends of the vinyl tube onto their respective nipples while dealing with the hose clamps and the restricted space. After 15 minutes of frustration, I heated the vinyl tube in boiling water for a few minutes and with the new flexibility it went on easily.A final binding problem can stem from the bungie or rope gettingpinched between the hub and the wall of the skeg box. The fix it toreplace the bungie around the shoulder of the hub and make sure the rope feeds straight up. A varient of this binding problem is the knot in the end of the rope where it ties to the blade. If your knotting technique leaves a lump it can rub on the wall of the skeg box. One quick fix is to pull the knot out of the depression in the blade, heat it with a match and while still gooey, pull it back to the blade and squash it down with something flat. Custom fit!We saw a cool trick at the workshop: tying a couple of knots in theline where it slides through the jam cleat to index various positionsof the skeg, e.g. up, down and halfway. The knots need to be smallenough to slide easily through the fairlead built into the jamcleat. Low tech and slick. I've seen it done on other boats byusing a permanent marker to mark index lines on the line itself whichalso works. The advantage of the knotting system is that with someexperience, you can set the line by feeling the knots as they pass:no need to look down.Another trick is to drill a small hole in the tip of the skeg bladeand thread a light line through it. Tie it into a loop that hangsdown below the hull a couple of inches. When the skeg jams, you cansimply reach under the hull and pull down on the loop. A good knotgives you something to grab or you can put your fingers through theloop for a really hard tug. This is easy for your paddling partnerto do on the water. You want to keep the line thin to minimize dragin the water.We had two boats at the workshop with the newer (2003 vintage)forward mount rope skeg setups. The idea was to have the advantages of a rope skeg (no kinks and field reparability without tools) with the advantage of being where it can be seen. Good idea, not so gooddesign in my experience. The rope is routed through a hole in thedeck about where the jam cleat on the old style rope skeg is mounted,follows a plastic tube under the deck inside the coaming and exitsinto a molded depression about where a cable knob would be mounted onthe deck. The rope goes through a small pulley and up to a flat jamcleat (mounted backwards in my view) that are both set into thedepression.In my opinion, there seems to be too much friction to work smoothly.More importantly, it would be a bit of a chore to thread a new linedown the tube and the relatively thin stock line cannot be upgradedwithout replacing the tube. This would make field repairs fussier,one of the things a rope system is supposed to avoid. One of theExplorers with this design was mine so I re-rigged it with the olderjam cleat behind the cockpit. This simply involved removing thehardware on the deck and the under deck tubing, plugging theresulting holes (I used epoxy putty but silicone caulk or glass woulddo as well), and installing a jam cleat in the traditional position.I find both the Romany 16 and Explorer relatively neutral to windforces which can be effectively compensated for by edging andminor corrective strokes. As a result, I've only used the skegout of necessity a few times. However, under the right conditions,either boat will weathercock with a vengeance and in those situationsa skeg is a major convenience and may be a real safety feature.Getting it and keeping is working smoothly will take some fiddling,but can be done.Scott Quote
Brian Nystrom Posted January 20, 2004 Posted January 20, 2004 I just want to mention a couple of things.1) In a couple of cases (Kim's Romany and Sean's Ellesmere), they got better performance using a thin polyester cord (1/8"/3mm), probably because it's more flexible than thicker cord. Either way, it appears that the key is making sure that the skeg assemby is properly "tuned" per your instructions.2) The type of cleat you installed on your boat is actually referred to as a "clam" cleat in most marine catalogs and web sites. Searching on "clam cleat" should make them easy to find. It's also important to get a cleat that has a fairlead. They're available with and without. Quote
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