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DDW

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Everything posted by DDW

  1. Possible but improbable. More possible if you haul after a short season. A well wielded moisture meter would tell the story....
  2. It isn't just the crews that vary, from other threads we know that "cruising" covers a vast range of sailing. For some it is nothing more than a Saturday night away from the home berth. Others have never seen the same berth or anchorage on two successive nights for years. Cross section that with the range of a 22 year old minimalist adventurer up to a well off 65 year old retiree used to quick room service and a single prescription for performance requirement is pretty meaningless. Further, a lot of us may go through every stage of that continuum over a lifetime. When I was 16 I happily cruise
  3. I don't keep anything on deck and have no 'crap on 'de back' at all - but this is as much an aesthetic choice as a performance one. However on weight, you have to make your choices. I specified my design, the length, beam, displacement, etc. When the NAs came back with the preliminary weight estimate (and a huge spreadsheet to back it) it was much more than my specified displacement, and I said as much. They said, OK, what do you want to give up and leave out? Well, nothing. So the lines were redrawn a bit more rotund. Then we built it and it got a little more obese at each stage. Ev
  4. The big majority of cruisers I see don't care much about windward performance. The don't care much about downwind performance either. This is told by their choice of sails, trim, etc. In many cases perhaps they don't know better, but in a lot of cases, I think they were just out to have a good time, not work, and it takes some extra work to get 95% out of the boat rather than 75%. I've always thought the design goal to peak the polars is misdirected for many people. Rather the design should allow getting to 90% with 50% of the effort. I can leave 10% on the design table but I'm sailing a
  5. It isn't just the finish. You start with dry plywood in your workshop and end up with moist plywood on the boat, it gets bigger even without the finish. This is why you leave flooring inside the house its going in for 8 weeks before you install - to let it settle at the ambient moisture content.
  6. As long as it drains out of the environment, it causes no harm.
  7. There are several mathematical models of lift, and a couple of popular ones directly couple circulation with lift. No circulation, no lift. The circulation results in the vortex at the tip of the wing. Whether the vortex is the result of lift, or lift the result of the vortex is a chicken and egg discussion. On those 6 and 12m keels, you have to look at them heeled at 30 degrees which is how they are sailed. The drooping winglets add quite a bit to effective span. That makes them a lift device, not a drag reduction device.
  8. Actually, though this has been the subject of a cover up for years, water draining from rudders in the cause of ocean level rise, not global warming as some would have you think.
  9. Oil film bearings are high load, but not generally low friction. They are used in places you might not expect (like disc drives and precision lathes) due to more predicable motion characteristics. An air bearing is a film bearing, air replaces the oil and being a lot less viscous has a lot less friction. One of the main reason sleeve oil film bearings are used in turbochargers is to accommodate the imbalance of the rotating assembly - the axle is allowed to do the hula in the bearing (and the bearing in the housing). Evans, if you have the two bearings it is pretty easy to test the rotat
  10. If you after the lowest friction, why not an air bearing? In low speed operation they are nearly frictionless.
  11. Keeping the strops in place is one thing you have to solve. Padeyes, lashings, something - they won't stay put on their own.
  12. FIFY. A SS post penetrating the envelope will eventually let water in no matter what you do. With a carbon post and good construction you have a pretty good chance of keeping it out. Imagine boring a 3" hole in the bottom of the boat, sticking a SS tube in the hole, and sealing around it with something. Now head offshore, giving the tube some firm twists and yanks every minute or so. You can tell the rudder is wet with a moisture meter (unless it is carbon skinned). I've walked through boatyards doing this and it is a rare exception that isn't wet.
  13. Crap. Garmin's purchase is often the kiss of death.
  14. Thanks for the recommendation, but wrong side of the continent. My reluctance to have a sail outsourced to the far east is due to my experience manufacturing there (and buying products manufactured there). That area is capable of great quality, provided it is demanded and constantly audited. For example, does the local loft in Penascola have on-site representatives at the loft in Sri Lanka that check to make sure the thread used is bought from, and delivered by, the approved vendor? If not it is possible or even likely that the thread is a less expensive substitute. You won't know until y
  15. Love to see the graphs. This is a 45' boat, but cat rigged so the sail is more like a 65' boat. Big sail (~95 sq m) but low aspect ratio.
  16. I'm in contact with Ullman in SC, they are the only loft that might actually build it there (and also the one suggesting Fibercon). As of recently, Pineapple no longer builds in house, if at all. If I have to go further afield, Seattle or LA area is next I guess. If it was a $2K sail with a few years life, probably just take a chance on something. This is likely to be somewhere in the $15 - $20K range. The original Stratis sail a bit north of that even. And there are a lot of little details to get right, unique to the boat so local is highly desirable. The most local is the Quantum loft
  17. Good question. Most of the local sailmakers have become sale makers, they take an order and send it on to China or Sri Lanka, so you are trusting them only to get the dimensions right, and are trusting unknown and unknowable people to get the design and construction right. If it is wrong the people responsible are half a world away. There are very few that have much (or any) experience with building a tri-radial Hydranet square head for a flexible rig. And almost none have any experience with the Contender material. So far I have found only one loft in the greater Bay Area that might actually
  18. You'd think though, if you are the newcomer trying to unseat the reigning champion, that you would provide more. Just going on that, it's hard to want to take the risk on a 5 figure sail.
  19. Yes, I saw the same propaganda and weave construction, and have the same questions. It is only in the heaviest cloth that there is any difference between warp and fill.
  20. I'm thinking harder about a new mainsail as the old laminate one has become more or less a pond liner. Some sailmakers are suggesting Fibercon Pro Hybrid as "just as good as Hydranet" at substantially less cost, Hydranet prices have apparently skyrocketed recently. Does anyone have good or bad experience with this material? Seems relatively new. Something not clear from their marketing propaganda is whether this is a true radial material.
  21. Right - it isn't just the location of the hole in the section, but how far from the end that is important. If the hole is very near the end, then all the aluminum has to do is stand up to the bearing of the bolts going through. I'd weld in a tube for that to increase bearing beyond the thickness of the walls (which should have been done from the beginning, then you wouldn't have this problem). If this was a vang attachment, then the strength might be critical as the bending stress is high.
  22. But is it 6000 series? I wouldn't weld it if it were, but some 5000 series aren't nearly that bad after welding. Maybe Hall can tell you, or you can have it tested. Also depends a bit on where the patch is. In some areas on a boom neither strength nor stiffness matter, some areas one or the other. The stiffness will not change much in the HAZ. For example if this is near the end of the boom, a 1/2 reduction in strength may not matter much - the section is way bigger than it needs to be there.
  23. Actually it is, near Trawno (or however you say it). On the Great Lakes, Canada has in many areas entered the 18th century and discovered cleats. BC, not so much.....
  24. It is possible to do outside jibes in theory! But the lines (halyards and reefing lines), wires (vhf, lights, camera) and hydraulic hoses would wind up. I've found it not that dramatic to do controlled jibes up to about 35 knots or so - the twin sheet arrangement is a great help there. Actually it is one difficulty with letting it go too far, the sheet angle closes up and it it hard to get it back again. In light air, it's hard to get it to stay out there - the mast has only 0.6 deg rake, but that is enough that the boom wants to center. If you look carefully at that picture you will see
  25. The winglets I installed (or I should say had installed by a licensed shop) came from the original manufacture (Schleicher) bespoke for that sailplane, so not an unknown. In fact until the end of the model run they continued to mold them without the winglets, if you ordered them from the factory they would cut the tips off and install their kit (probably near 100% were sold that way after they introduced the winglets). Yes, you simply sawsall the tip off, install a tip rib with the connection features, plug it in (they come off in the trailer), and fair and finish. Makes you a little sick when
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