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Tom Lathrop

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Tom Lathrop last won the day on December 5 2016

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About Tom Lathrop

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  • Birthday 09/17/1931

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    Oriental, NC
  1. Fuel Tanks, Splash well, Windows...

    There's a whole heap of energy tied up in those little boxes. No problem as long as it is let out slowly but, if released suddenly, bad stuff can happen.
  2. This is an interesting topic. I was able to sail on all points and tack readily in BRS Loon in both light and fairly strong wind. I find that Lapwing is not nearly as cooperative but have not tried it enough to be certain of the reason. It may be that the hard chine of Loon provided enough turning moment to aid the rudder and the round hull of Lapwing could not do that. Note to Peter. Sailboat brakes were first introduced in 1926 by Manfred Curry and were just as quickly ruled illegal by the racing authorities. He had a flap on each side of the rudder that could be pulled down into a effective large vertical flat plate which caused all kinds of angst among his competitors.
  3. sail trim

    Yeah Alan, I know that threading the loop can be a bit difficult in strong wind and the reefing lines can help maintain control to some degree. Unless the reefing lines go to a point where the crew does not need to hold on to a banging sprit near the clew end, the advantage is partly washed out. I've only reefed Lapwing once in its lifetime and that was not really necessary as we could have handled the full sail and had more fun. I never ever reefed Loon (the Bay River Skiff). Lapwing has wishbone booms, battens and sail tracks. For most day sailing, I would prefer to go back to laced on sails, no battens and straight sprits. Very little performance is lost and the payback in simplicity, rigging time and effort is a great reward. As the boats get bigger, the extra effort begins to pay off but not nearly as much as some may think. Of course, I'm getting a bit long in the tooth and sailing needs to be simpler or it won't be enjoyed. My fleet is shrinking as one sailboat and one powerboat is being sold and Lapwing is going to Maine to live with son Mark.
  4. sail trim

    Why is there a reefing line anyway? I insert the tip of the sprit in the loop at the reefing cringle/point just like as at the clue. The sail shape is then controlled only by the snotter and no other lines are needed.
  5. Centerboard trunk

    I'm afraid that your Lapwing has had some serious issues in either building or maintenance in its earlier life. Since you bought it in 2012 and it has not been stored in any exposure to the elements since then, it had a pretty short lifetime to incur all that damage. Probably no more than 5 years and likely less than that. Good plywood just doesn't go bad that fast even if it was only painted. I'd venture that someone owes you an explanation. I'm the owner/builder of the original Lapwing which has been simply protected by a tarp cover for its life of a bit less than 10 years and it has no such problems at all. Its very distressing to see this kind of damage on a S&G boat and even more-so on one so young. There is a ply/glass/epoxy Windmill sailboat sitting alongside Lapwing that has not had the level of protection as Lapwing and it does not have anything approaching this kind of damage although it is 24 years old. I think that at least a new DB trunk is in order
  6. Sharpening Chine and Transom edges?

    I very much doubt that anyone could detect a difference in drag/speed in slight rounding of the transom edge on a Bluejacket. On a very small boat the percentage of drag increase would be greater than on a boat, of say 16, feet but still not measurable at normal speed for our boats. On a racing sailboat, I might sharpen the transom bottom edge and foil trailing edge but not anywhere else. Some of the difference that might be seen is probably due more to perception than reality. Feeling good about the potential of your boat may be as important as any actual advantage. On a Bluejacket, I would go for the small radius edge that will hold whatever surface you put on it. It is far more rugged and you will never see any difference in fuel use, speed or anything else. All liquids hate a sharp edge and will pull away from it. The technical term for this tendency is called "surface free energy" or surface tension by the layman. This is what makes it so difficult to cover a small nail hole or pinprick hole from a bubble in paint.
  7. Bluejacket's a winner!

    Good on ya Chuck and not to forget Betsy. Tom
  8. Carlita's new adventure

    I was suspicious of that and maybe we should have foreseen the possibility of salt water puddling at this point. It is one of the issues with using non anodized aluminum for masts. A drain might have prevented the failure but, who knows? May need to rethink how stress relief is engineered. Just having a thicker mast section would not have failed without any reinforcement but weight, especially aloft is always a bugaboo.
  9. Carlita's new adventure

    The weakest point of any unstayed mast is where it exits the deck or,in this case, at the connecting point of the tabernacle. What you are looking at at the stub on Southern Skimmer ( if my memory is correct) is an insert made with a double layer of carbon weave over a foam mandrel. The break appears to be at the end of the insert which was inserted to reinforce and distribute stress away from the exit from the tabernacle. Since even a double layer of carbon weave is not nearly as stiff as the aluminum mast, it was thought that this was a good idea. The fact that the greatest load would be at the bolt through the mast on the tabernacle, it seems strange where the break occurred. Has the aluminum mast suffered any physical or chemical damage at this junction? I would like to see the result when they get home. This mast has survived some severe loading in rough conditions since it was built. Temporary running side/back stays are used when the spinnaker is flying.
  10. Torsion Box Roof construction

    Jeff, I sent you a couple drawings by email..........Tom
  11. Torsion Box Roof construction

    I guess I should enter this discussion. On the Bluejackets, I expect that both decks and pilothouse tops will have people walking on them at times. The foredeck especially may have the occasional jackbooted dockman jumping on it. Therefore each was designed to suit the expected loads that would be placed on it. I specify 1/4" ply for the top layer but 3 or 4mm is adequate to handle the tension loads on the bottom of both. Spacing of internal ribbing (laminated 3/4" beams) is also closer in the foredeck for the above reasons. In Jeff's application, there will not be any need for supporting heavy or concentrated loads on the structure so it can be designed and built with this in mind. I would choose 4mm ply for the top and bottom skins and perhaps less interior structure as well. The foam is not only for insulation although that is a plus. The blue or pink 3/4" styrofoam also offers rigidity and additional support for the thin skins. The more curvature that is built in, the more rigid the structure will be. Depending on the area of the hardtop, wind loading may be a factor and the mounting must be strong enough to handle that when the top is extended. If Jeff sends me an email, I can email a drawing of the BJ pilothouse top with notes of recommended differences.
  12. RIP Hugh "Buck" Wilde

    Very sad for down east boatbuilding folk. Buck's body could not maintain pace with his mind.
  13. Cetol over epoxy?

    Chuck, After some reflection, I remembered that Sikkens says that it is porous and able to breathe through to the wood underneath. Over epoxy, that would not be possible so that may be why they say to coat only bare wood with it. Anyway I have gotten better results with Sikkens over bare wood than any other product. Of course, if I want the best looking finish and know that it will not be exposed to the elements all the time, I use Z Spar Captains or Flagship.
  14. Cetol over epoxy?

    Chuck, I cannot answer the question, but it is probably best to follow Sikkens directions. I have used both polyurethane and varnish over epoxy many times with good results. When I redid LIZ's rubrails last year I used SIkkens Window and Door finish since it gave me really great results on our mahogany front door that is in full sun half of he year. (The door is on the website and gets redone only about every 4 to 5 years) I stripped the poly over epoxy with a heat gun and think this will be longer lasting. The Window and Door variety does not have any of the orange tint that some Cetol has. It does not have quite the depth look that fresh varnish has but after six months or a year it looks much better than varnish and then lasts for a few years more before demanding to be redone. It does take a lot longer to dry and stand up to abuse but I can live with that for its good qualities. I have to order that particular variety of Sikkens as the local stores only handle the marine versions. They may offer the same good results but I stick with what I know.
  15. Carlita's new adventure

    Graham, What would be the effect of allowing the main rudder to react more easily by having it restrained by weak shock cord rather than being tied down on center? Not good, I suspect as the main rudder is helping directional stability but don't know for sure.
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