refitting a twin keel

Discussion in 'Sailboats' started by astarte, May 4, 2012.

  1. astarte
    Joined: May 2012
    Posts: 2
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    Location: florida

    astarte New Member

    hello all i'm refitting a tylercraft twin keel with a new mast it is a foot or so taller and an inch bigger all around the old mast was damaged and i'm not sure if the hight is still the same as when it was new. i have to replace the mast step as well due to the larger diameter the standing rigging is like new on the new mast but a smaller diameter the old mast has standing rigging with crimps and clamps at all ends. is this exceptable? i'm thinking i should use the new rigging that came with the new mast or replace it all.

    any suggestions would be appreciated especially about the mast step.
     
  2. Eric Sponberg
    Joined: Dec 2001
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    Location: On board Corroboree

    Eric Sponberg Senior Member

    It's a little hard to make out your request without proper punctuation. What I read is this: You lost your old mast and bought another mast--I would guess a used one that you picked up somewhere, and it is "an inch bigger all around." Do you mean an inch bigger in circumference (i.e. all around) or an inch bigger in diameter, both fore and aft and athwartship? If it is an inch bigger in circumference, then the old and new mast are pretty close in size, but if it is an inch bigger in diameter, then that is a huge difference. Being that much bigger probably means that the new mast is a lot heavier, and that is going to have a not-so-good impact on the boat's stability--the boat is going to heel more if there is a lot more extra weight up high. The bigger, newer mast is also going to have more drag than the older mast by virtue of its bigger size. Both of these factors--extra weight up high and bigger section--are going to give you less performance than before. The boat will likely not sail to weather as well, and it will be slower.

    Next, it seems that the rigging wires with the new mast are generally smaller in diameter than the older rigging wires. Rigging wires (and mast sections) are generally designed to the righting moment of the boat. What was the overall weight and the width of the boat's beam where the new mast came from? If weight and beam are reasonably close to your boat, then the mast and rigging might be a good fit. But if your boat is heavier and/or wider, then the loads on your rigging might be more than what was designed for the new rigging. You can check this my multiplying beam x displacement for each boat. If the results are reasonably the same, say within 10% of each other, then the rigs are nearly equivalent. But if the results are quite different, then you should stick with the old rigging. If the original wires are in good condition, use those because the ones with the new mast might be undersized. It is OK to have crimps and clamps if they have survived well--that's how they did it in the old days. If desired, you can also use new fittings such as Norseman (maybe out of production) or Sta-Lock--nothing wrong with those.

    I hope that gives you some guidance.

    Eric
     
  3. astarte
    Joined: May 2012
    Posts: 2
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    Location: florida

    astarte New Member

    Sorry about the puncutaion. I'll try not to come on here when I am rushed. However you have answered my question. My boat is new to me as is sailing. Comming from a comercial boating back ground, i. e. oil field captain, fishing charter boat captain, and more gives me some experance. I traded an old harley I could no longer ride for this boat. The boat's mast has a repair that looks precarious. i found a mast from a Macgregor. The mac. and my boat are the same length but my boat has an eight foot beem and is much heaver. the new mast is a foot taller and .75'' wider and an inch thicker than the old mast 2.5 x 3.75 the mac or new mast is 3.25 x 4.75. The spreaders are at the same hight and the top of the mast is where the extra foot in hight is. I can't feel any noticable differance in weight when carrying them or lifting one end in each hand. the mast lights are the same hight. the top of the mac's mast is welded aluminum and the old Tylercraft mast has a heavier steel top bolted on with a foot long pice of galvinised pipe for the mast light. Thank you for responding your input is welcomed.
     
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