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pointing up wind

Discussion in 'Canoe Sailing' started by Michael Leone, Aug 22, 2006.

  1. Michael Leone

    Michael Leone You call that a sail?

    I recently completed my 1940's mahogany veneer sailing canoe and have had
    a chance to give it a good workout on a week long camping trip in the
    Adirondeacks. the wind was up all week, often blowing whitecaps and on
    one afternoon sailing upwind in a gail in front of what turned out to be a
    severe thunderstorm with marble size hail!
    what I discovered is that I am having a hard time getting it to point upwind
    much higher than 20 degrees off of a beem reach, also I noticed that it will
    point a little higher in heavy air, maybe 25 dergees.
    It is a 16 foot canoe with 36 inch beam and a flat bottom.
    A 55 sq.ft. three batened lateen with 6 inches of roach on a fairly short
    mast which keeps the yard from peaking up much higher than 45 or 50
    degrees, giving the whole rig a fairly low aspect.
    It has good lateral resistance with 48x10 well foiled leaboards and 18 inches
    of rudder 8 inches wide below water.
    Is there anything that can be done to tweek a lateen rig to get it to point
    higher?
    Is the angle of the yard critical?
    Are there other low aspect rigs that point up better?

    any input would be helpfull.

    Mike

    PS. would anyone like to join me to do some sailing off of Sandy Hook NJ.
    in September?
     
  2. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Since the typical sailing canoe is a combination of various store-bought and home-made, home-designed parts, it's hard to be very specific when discussing performance issues. Add-in the fact that all the hulls (which tend to be a fairly important part of a sailboat) are different sizes and shapes and top that off with the fact that the boats are extremely sensitive to fore-and-aft trim and things get even more vague.

    Lateens aren't known to be extremely high pointers, but aren't generally too bad. A Sunfish, for example will sail decently to weather for a simple boat. Peaking-up your yard to a steeper angle is probably worth trying. Gaffs and yards with higher peak angles tend to create more lift and point better than those at lower angles. Snugging your outhauls on both the yard and boom might also help as it will flatten the sail a bit and flatter sails sail upwind better. Since there isn't a good way to adjust these on the fly, you may lose some performance on other points of sail where more draft is helpful, so the aim is usually to try to find the best all-around outhaul tension and live with it on all points of sail.

    If you're pointing better in heavy air, it's possible that it's being at least partially caused by the spars bending more due to increased wind and mainsheet tension. This tends to use up the sail's luff and foot curves and flatten the sail into a better pointing shape. Whether or not this is happening depends mostly upon how the sail was cut and how much spar bend was figured into it's design. At some point, nearly every spar will bend enough to defeat the luff and foot curves' draft-creating abilities and the sail will go pretty flat. Ideally, this point will be caused by the wind pressure and sheet tension of your typical upwind leg in the conditions that you most often plan to sail in, but it's always a compromise based upon estimation and not an exact science.

    Heeled-over hulls (common in higher winds) also have a tendency to round up into the wind more than hulls sitting flatter on the water. This tends to create more weather helm and correcting that with the rudder to stay on course causes more drag, wasting power in the process. Some boats (like the Sunfish, for example) sail much more efficiently to weather when kept flat by hiking than they will if you let them heel way over. On the other hand, the hull of a boat that's heeling and wanting to round up into the wind can sometimes carve a slightly higher course through the water, just from the hull shape/water interaction. Extreme angles of heel are almost never particularly efficient in terms of either speed or pointing angle, but it's worth doing some fairly careful test sailing to try to figure out what amount of heeling seems to work best when trying to point. You may even find that in certain conditions, the boat points higher flat and in other conditions and wind speeds, it points better with a moderate amount of heel. Fore-and-aft trim can be a huge factor in sailing canoe handling since it can drastically change the under water shape of the hull, both how it goes through the water and what parts are creating lateral resistance, so that's another area for experimentation.

    I'd stick two or three telltales on the leech, primarily to be able to see when the sail is over-trimmed. A telltale hiding behind the sail means that at least that portion of the sail is over-trimmed and needs to be eased out until the telltale is flying. This will help to insure that you're not trying to point with half of your sail stalled-out. I'd also either build or buy some kind of small, bright-colored buoy that will show up from a couple hundred yards. A kids' play ball with a string attached and a rock for an anchor will work. The reason is that it is much, much easier to test various configurations of sail trim, heel angle, fore-and-aft trim, etc. (as well as polish your sailing technique) if you have a specific target to sail toward. With two buoys, you could set up a windward/leeward course and you would be amazed at how much you can improve your sailing and how much better your testing will be when sailing toward fixed objects that don't move and which eliminate any fudge-factor.

    There are certainly other sail types which will usually point higher than lateens, but most are taller, higher-aspect sails with longer, more vertical luffs. Even so, switching types doesn't automatically guarantee any kind of vast improvement and I wouldn't jump ship on the lateen yet. It's not unusual to spend a couple seasons sailing a new boat before you really get the hang of it and are getting the best performance out of that particular rig. Quality practice and testing time is the best bet for the moment. It's a tough job, but somebody's got to do it!

    Sorry I couldn't be more specific, but sailing canoes are a compromise made up of estimations and variables and every one is it's own unique equation, waiting to be solved. If it was too easy, it wouldn't be any fun.
     
  3. OP
    OP
    Michael Leone

    Michael Leone You call that a sail?

    Thanks Todd

    that's plenty to chew on, and I know I need to spend more time on
    the water under different conditions.
    As far as trim goes I have not been able to detect any notable helm.
    weather or lee, to my surprise it sailed strait as an arrow with neutral
    rudder first time out due to my precise calculations while setting up the
    rig, Not!
    I like the idea of setting out markers, I will definitely try that, and I will
    also add telltales.
    what type of line should I use for the telltales and how long should they
    be, and could you elaborate on how and what the telltales are doing and
    how to read them in relation to what I should be doing with sail trim and
    rudder.
    I will post some pics of the rig and my trip latter.

    thanks again Mike
     
  4. Todd Bradshaw

    Todd Bradshaw Sailmaker

    You may want to adjust your leeboard angles or the position of the leeboard bracket so that they tend to produce a little bit of weather-helm (boards moved forward just a bit). This may help increase your pointing angle through hull/water interaction a bit and it's also a pretty good idea from a safety aspect. Should you fall out or for some reason become incapacitated (too much beer?) the boat will tend to point up, stall out and come to a stop, rather than sail away on it's own.

    On traditional sails, I use yarn for telltales. I take a big needle and poke a strand of yarn through the leech hem, tie a stopper knot on both sides of the sail and leave one end of the yarn about 8" long hanging off the leech. The only problem with yarn is that it sometimes tends to get stuck on lines of stitching as it's flapping around. You can usually shake the sail and free it so that it flows again. Small strips of very light nylon (1/4"-3/8" wide) can also be used, sewn or stuck to the sail. They aren't as traditional, but tend to be less "sticky".

    I'll sometimes stick a pair of telltales (both sides of the sail) near the upper middle on a lateen, but turbulance caused by the mast on one side can make it somewhat less than 100% unreliable. You can see a small round vinyl telltale window on the lateen in the attached photo. The window makes it easier to see what the telltale on the back side of the sail is doing, but you can usually see them through the thin sail fabric even if you don't have a window for it. Two or three single yarns spaced out along the sail's leech tend to be more helpful in most conditions.

    Reading the telltales on racing sailboats during various maneuvers can be pretty complex, with lots of subtle indicators of what the airflow over the sails is doing and what to do about it. For our purposes with simple rigs, we don't need to get that deep into the aerodynamics. For the vast majority of our sailing, having as many of our telltales flowing and streaming aft as possible generally means we're doing a pretty good job. If a pair of port and starboard, mid-sail telltales are both plastered up against the sail, your airflow is attached on both sides and you're trimmed pretty well. If the leeward telltale isn't flowing, it means your airflow has detached on the leeward side and you need to ease the sail until it's flowing again. On the other hand, if your windward telltale isn't flowing, you need to trim the sheet a bit, pulling the sail in until hopefully both telltales start flowing again.

    One way to sail your highest possible course to windward is to trim the sail in pretty tightly and leave it there. You then steer by watching the telltales and playing the windshifts. You either head up slightly or bear off slightly any time one side's telltales stop flowing (leeward telltale stalls - head up, windward telltale stalls - bear off). You make small heading adjustments as needed and as soon as both sides' telltales are flowing again, you hold that course.

    For the most part, leech telltales show you when the sail is over-trimmed (pulled in too far). If it is, they tend to curl around and hide behind the leech. If that happens, it means that the airflow over the sail in that area has become detached and that portion is starting to stall out. Easing the sail until they are all flowing again will generally fix the flow and get your entire sail working again. Most people tend to over-trim on a regular basis, so the general rule is "If in doubt, let it out."

    You will also find instances where you just can't seem to do anything which gets all the telltales flying at once. On simple rigs with very limited sail-twist/sail-shaping/sail-control systems (like most canoe rigs) this happens sometimes and about all you can do is live with it. Practice and experimentation over time will usually teach you which levels of sail trim and adjustment produce the most speed and the highest sailing angles.

    For those who haven't sailed a canoe or small boat, sailing doesn't need to be as complicated as this post probably makes it seem - and it really is fun. Like any other sport, it depends upon what level you want to take it to and the mechanics of being really good or efficient at it take concentration and practice, the same way a sport like golf does. Even a canoe with a simple add-on sail rig can be a complex proposition if you're trying to wring every last ounce of performance out of it. And since it is an add-on rig, it often takes a while to get it de-bugged and adjusted for best performance. Just part of the game (although sitting on the bottom leaned up against a thwart on a nice, light-wind day and just watching the woods as you slowly sail by isn't half-bad either
     

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  5. Treewater

    Treewater Wooden Canoes are in the Blood

    This is an old thread but addresses the issue I have with canoe sails. My trip with an Old town sailing rig was a bit of a disappointment. I could not get the canoe to sail much more than 10 degrees into the wind. As well, on one tack the sail, the lateen rig, will be against the mast and you lose sail form. Going down wind was best though it rocks dangerously in high winds for some reason. Cross wind was okay as long as I determined which side to put the pully and gaff to get proper sail form. My goal of sailing six miles into the wind in one day was just not possible. If sailing into the wind is my goal, and why should it not be since it is so hard to paddle, am I better of with a small sloop rig to include the jib sail? I will admit, I used an outboard motor in the final effort to get home each day. There just was no other way. I'd hate to think the outboard is the only way.
     
  6. Paul Waqué

    Paul Waqué Enthusiastic about Wooden Canoes

    Todd has some very good comments.

    Sailing six miles into the wind is quite ambitious. The low aspect of a lateen sail is not ideal for generating lift upwind. For upwind sailing especially the sail needs to be a good airfoil generating lift and a longer leading edge helps.

    Going downwind, your leeboards are still generating lift and can contribute to the unsteadiness. You might want to try and reduce the wetted area of the leeboards when sailing downwind.

    Paul
     
  7. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Most people have found that the spars interfering with one side of the sail on one tack on lateen and lugsails doesn't usually seem to make very much difference in performance, despite the fact that it makes your sailshape look pretty funky, so I wouldn't worry an awful lot about that part unless you're getting obvious drastic differences in performance from one tack to the next.

    As for the downwind rocking, it's the precursor to what's called a "death roll" and to be avoided. The usual cause on sails with yards or gaffs up high is easing the sail out too much. The upper part of the sail will always twist off to leeward more than the boom or the lower part of the sail. This is normal and in some cases, a good thing as the wind up high is faster and also shifted a bit. However, if you let the sail's top twist too far, you start to get this strange oscillation going and it can literally roll you right over. The general rule of thumb to avoid this is to keep the top spar and/or top part of the sail trimmed tightly enough that it may be 90 degrees to the keel line, but it doesn't go forward of the mast. On sails with battens, where the top batten is typically one quarter to one third of the way down the leech from the top of the sail, we usually instruct people to ease the sail out on a run until the top batten is 90 degrees to the keel line, but no farther than that. This is to avoid the death roll.

    You also want to be sure that when sailing downwind angles, you're not "sailing by the lee". You can probably let the sail out on either side of the boat and it will sail downwind, but on one side, the plane of the sail will be closer to the wind direction than when he sail is on the other side of the boat. The angle between the boom and wind will be smaller. You always want your sail on the other side of the boat - the one with the bigger angle and more difference between the wind's angle and the boom's angle. That way, a sudden wind shift is less likely to catch the sail's leech, whip the boom across in an unintended jibe and take your head off.

    As I said above, canoe sailing rigs and their parts vary so much that it's hard to say what you would need to change to get better upwind performance. I'd keep the boom as low as possible up front, peak the yard fairly steeply by adjusting the halyard tie-off point, snug up the outhauls to flatten the sail and start playing with the leeboard position and angles. Also as mentioned above, practice sailing toward a fixed target can really give you a better idea of what's really happening and make that practice time a lot more meaningful.

    A sloop with a jib will usually point higher, but jibs on unstayed masts usually tend to have an awful lot of luff sag, which isn't great for upwind sailing. I've even built lateens with reefs that could be swiveled upward to make room for a jib, though the intention was more one of boosting sail area in adjustable increments for light air than improving pointing ability. With something more typical of sloops, you might end up with a lot more rig height than you want to be counter-balancing. If I had done serious experimentation and was convinced that I wanted to move from a lateen to something that pointed better, I'd probably be looking at a rig similar to a Class C canoe sail, and probably a gunter.
     

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  8. Treewater

    Treewater Wooden Canoes are in the Blood

    Sailing six miles into the wind is quite ambitious. Well I wondered about that. Guess I need to scale down my expectations. I eventually moved to sailing downwind w/o lee boards in the water. That at seemed to work fine since leeboards serve no purpose downwind. In light breezes even the rudder I took in as paddling on one side kept steerage and contributed to motion. But Todd's phrase "death roll" is a bit scary. However, that was what I saw coming and in the situation I had, I took down the sail and resumed paddling. Todd your explanation sounds very accurate and I will pay more attention to the set of the sail in the future. I know from previous sailing that one can get a little lazy downwind and not pay close attention to sail details. I knew something was wrong from watching the top oscillate madly but didn't know why.
    Thank you both. IMG_2068.JPG
     
    Last edited: Sep 25, 2011
  9. Todd Bradshaw

    Todd Bradshaw Sailmaker

    You also will probably find that your boat moves a lot better and you get from point A to point B quicker by avoiding sailing dead downwind and instead, link a series of broad reaches at somewhat higher angles to the wind. You'll sail farther, but a lot faster and arrive sooner. Downwind runs are nice if you need a break and want to rest, but on a boat like a canoe that reaches very well, they aren't very efficient.

    Six miles upwind can be a lot in some conditions, especially when the actual distance you need to travel to do it is substantially more than six miles. The big lake here in town is about five miles accross and I can remember a few days when we crossed it upwind in a pretty good wind and chop and by the time we got across, we were really beat from the pounding, and that was in a 20' trimaran. About 2/3 of the way across, it ceased being fun and just became something you wanted to get over with a.s.a.p.
     
  10. Paul Waqué

    Paul Waqué Enthusiastic about Wooden Canoes

    Nice picture Treewater.
     
  11. Treewater

    Treewater Wooden Canoes are in the Blood

    Pictures? Here's more.
    1. canoe and motor in shop
    2,3. canoe on lee boards, finally on logs
    4. sail on good side of mast
    5. sail on wrong side of mast (Todd says this is okay)
    How long can a sail be used? these are patches. a 1948 sail, sewn patches when I got it. liquid glue I used to repair mouse holes.
    7. Gear is in the way of hoisting the sail, paddling

    IMG_2017.JPG IMG_2021.JPG IMG_2051.JPG IMG_2034.JPG IMG_2029.JPG IMG_2052.JPG
     
    Last edited: Sep 26, 2011
  12. Treewater

    Treewater Wooden Canoes are in the Blood

    Web site must be limited for pictures.
    Heres the motor, the long patch with liquid glue, some blue sky and the end.
    IMG_2057.JPG IMG_2063.JPG IMG_2067.JPG IMG_2070.JPG IMG_2074.JPG
     
  13. Paul Waqué

    Paul Waqué Enthusiastic about Wooden Canoes

    That is some full-on canoe camping; sailing, motoring, big cooler, even a folding steel chair. Looks like fun, and what the canoe was made for.
    Paul
     
  14. Todd Bradshaw

    Todd Bradshaw Sailmaker

    The sail doesn't look too bad for an old one. It has some patches, but the shape looks pretty decent. As can be seen in one of the photos though, the cotton really soaks up water like crazy, and the better the grade of cotton, the faster it will do it. It would be a very good idea to pick up a squirt bottle of "303 Fabric Guard" (I get it from Amazon) and spray the sail with it. Once done, you can't see any difference, but it is an excellent for both resistance to water and UV damage. At this point, it will probably double or triple the remaining life span of the sail, as well as prevent the potential moisture absorption from leading to mildew. I just built a couple of cotton sails and the difference between treated and untreated cotton is pretty amazing. Without the 303, the cotton absorbs water like the best sponge you've ever seen. After the treatment, water beads on the surface and then rolls off onto the floor. I think I paid something like $18 for a big bottle of the stuff, but it's absolutely worth every cent.
     
  15. Treewater

    Treewater Wooden Canoes are in the Blood

    Thank you Todd. I knew I had a wetness problem but it didn't occur to me treating the fabric even while I treated the tent fabric. Yes, sailing with cotton means constantly laying them out to dry.
     
  16. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Considering that after it dries, the stuff is invisible and the fabric feels exactly the same, the difference between 303-treated cotton and untreated cotton is quite dramatic. I set these on the counter and poured maybe three tablespoons of water on them from a teacup and took the photo a couple minutes later. The untreated piece was totally saturated within about ten seconds and by the time I went and got the camera most of the water had already run off of the 303 chunk.
     

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  17. Treewater

    Treewater Wooden Canoes are in the Blood

    Hello Todd,
    I just put 16 oz of 303 Fabric Guard on my sail today. Wow! I'm impressed. That old sail sure soaked water when I was out and now the water runs right off. Wonder how long it lasts. I recomend it to anyone.
    Tim
     
  18. Todd Bradshaw

    Todd Bradshaw Sailmaker

    It will likely last several years on a sail. The UV absorbers do get used up over time (if you're lucky enough to get that much sailing time in) and need to be periodically refreshed with new ones, but that's more of an issue on something like a boat cover that sits out in the weather. For recreational sailing, a treatment every five years or better will probably be plenty to protect from UV.

    If you notice the water repellency starting to fade, or if you wash the sail, the first thing to do is to iron it. This somehow recharges the stuff. It's the same sort of fabric treatment that you'll see on a lot of outdoor gear, including items like GoreTex raingear. Gore Tex and similar coatings and laminates always work best if you can block a good deal of moisture from ever even getting to the coating itself. This is done by treating the outer fabric so that it doesn't absorb moisture and hold it next to the coating, and the substance they use to treat the fabric is basically very similar to the 303. The care tag inside one of these garments will tell you how to wash it, and then usually says something about ironing the garment. This isn't done to keep you from looking scruffy out in the woods in a wrinkled coat, it's to reactivate the water barrier provided by the treatment. I can remember reading the tags and thinking that I really didn't care whether my outdoor garments were wrinkled or not, and that ironing them would be a true waste of my time. After finding out the real reason they suggested it, it made a lot more sense.

    When they get to the point where ironing won't bring back the water protection, then it's time to buy another bottle and re-spray them. Also note that 303 is not a silicone spray like some of the sprays sold for outdoor gear. It's a flourocarbon spray (not the type that destroys the ozone layer). The two types, fluorocarbon sprays like 303 and silicone sprays like Camp Dry and others, don't tend to get along very well. Mixing them tends to cause spotty coverage as they try to repel each other, so it's not wise to switch from one to another.
     

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