What's in the mast?

Discussion in 'Sunfish Talk' started by fullkeels, Feb 14, 2008.

  1. fullkeels

    fullkeels New Member

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    I just removed the end caps from my booms to discover that they have cork-like plugs running most of their length. Does the mast have a similar floatation arrangement? I'm making a mast for my fish from anodized aluminum tube and would like some recommendations for floatation if it's desirable in the mast. Would it be better to try and make the mast watertight by permanently affixing the top and bottom caps with 5200 or epoxy? My first impression is that it would be best to keep the caps removable though.

    Thanks to everyone who has given me great help, information and ideas. They are much appreciated!
     
  2. mike4947

    mike4947 Member

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    Back in the olden days there used to be an inch or so cork plug in the mast ends. Over the years it was found it was basically useless and actually tended to hold water.
    Myself I drill a 3/16" hole near the base cap so any water that does migrate into the mast will drain out between sails with the mast out of the boat.
     
  3. DanB

    DanB Crabber

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    I’m with Mike on the drain hole approach. Go easy with the heavy duty sealants if you do plug it up. You might want to open the endcaps some day and not have to destroy them in the process. A thin seal of boater’s silicone seal at the seams and a dab on any cleat fasteners is all that’s needed. Remember to put a small squirt into any pop-rivet centers if you use open ended rivets.

    The most buoyant mast would be an empty sealed one. Better be darned dry inside before you seal it up. Full fillers seal out water, but add weight. You’d get more float from adding less to the outside at the very top of the upper spar. I’ve seen the large center hole pool noodle cut to fit between the first two to four sail clips and slid over the spar. Hardly even noticeable when color coordinated with the sail stripe. And there’s always the gallon jug hung on the top spar. Been the “Fish” standby for half a century.

    With a little experience going turtle is rarely an issue. Watch a few of those You Tube videos. Some of those guys don’t even get their feet wet righting the boat.
     
  4. fullkeels

    fullkeels New Member

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    Thanks for the replies fellas. Mike, you're right - there is in fact only a small section of that cork-like stuff at the spar ends, not the entire length like I previously posted. I know you guys are speaking from your personal direct experience with these boats which I completely lack, but I suffer from this strong sense of thinking that watertight is the best way to go as far as the spars are concerned. For example, it's inevitable that some of my crazy powerboater friends from will borrow my fish when its completed, and I can vividly imagine the sight of my mast becoming part of the Great South Bay bathymetry, the booms getting run over by a cabin cruiser, and the sail getting jammed up in a jet skier's impeller.

    What if I use a loctite type sealant that can be undone with tools, coupled with a bead of silicone smoothed around the external circumference? However, if I take that approach I'm worried about the expansion/contraction pressure and temperature changes within the watertight spar causing a leak and possibly filling the mast in the event of a capsize(s). I'd rather be the one getting the good chuckle of watching my friends try to sail, but at the same time knowing the boat's equipment is safe.

    Last question. Since I'm making a mast from tube aluminum, should I invest in the mast sleeve add-on from the manufacturer or is there anything I should do to make the mast more rigid? Thanks again.
     
  5. Repete

    Repete Sunfish1909

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    Fullkeels, is your mast tube, the one your are constructing, anodized? Mill finish or bare aluminum will "bleed" black with the metal rubbing off. Your sail cloth and deck as well as everything else will collect these black stains. An anodized finish is harder. If you can find a prefinished section of a handrail or flagpole from a scrap yard or recycling center that is anodized, that would be your best bet. If you stay with the bare aluminum stock, you will need to prime it to receive a hard paint finish (epoxy?). Some of the other skippers I am sure can chime in with the finishing processes available for aluminum.
     
  6. fullkeels

    fullkeels New Member

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    The metal is 6061 t-1 clear anodized aluminum.
     
  7. DanB

    DanB Crabber

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    I don't know if Loc-Tite is worth the aded expense. I can't see it providing any more sealing benefit than a thin film of silicone caulk. I can tell you this, silicone works best (lasts better) in a film betweeen things rather than a bead that can be scuffed and peeled away.

    Expansion and contraction probably isn't a worry. Think of the pressure a .020" popcan endures. I've sealed mast and spars and never experienced a problem. Keep it simple and easy to take apart down the road.

    If you are run over by a power boat I'd think springing a leak in the mast and spars would be the least of your worries.

    6061 is a good guess. Certainly one of the more common "aircraft aluminum alloys" available. Could be 6063 alloy or T3...7 heat treat too ?? Anodizing adds little if anything to strength. It's just an acid bath treatment to react the outer microscopic surface and make it resistant to oxidation. No mollecular magic seeps into the core of the metal in the process.

    If you miscalculate the hardness and tensile strength of the alloy then the sleeve kit could add strength by increasing the wall thickeness. It may also be a harder alloy. I don't know its qualities beyond the obvious. Call L.P.Vanguard, maybe they'll share the all the mast info.

    What is this mast costing you? I've always found short length quotes to nearly equal the retail of a Sunfish mast.
     
  8. Wavedancer

    Wavedancer Upside down? Staff Member

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    Regarding the mast sleeve question, it depends.... (doesn't it always :))

    It depends on the conditions that you might be seeing. Specifically, mast problems have shown up where the boats have been sailed really hard by racers in strong winds with big waves. Unless you plan on sailing frequently in those conditions, my recommendation would be to keep it simple.

     
  9. mike4947

    mike4947 Member

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    Actually the sleeving started when IIRC Vangaurd decided to use the same tubing for Sunfish and Laser. The earlier Fish tubing was, again IIRC, a thicker wall. So when they started getting failures they came up with the sleeve to reinforce the area where they experienced failures on the thinner wall current tubing.
     
  10. fullkeels

    fullkeels New Member

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    Thanks again for the help guys. To answer Dan's question, the mast will cost me about 50 bucks from an aquaintance plus an extra 20 for the manufacturer end caps. So I'm saving almost $100.00 give or take. I'm taking your advice to seal up the spars with silicone, but I happen to have lots of loctite. The graphite/MoS2 coating I will be using for the hull bottom, sides, daggerboard and rudder of "Passing Wind" will be wet sanded and burnished Lubribond B (epoxy matrix) at about $37.50 per quart. I'm first sealing the entire hull with the Interlux 2000E epoxy barrier system. My jury is still out for the coating on the topdeck. The total restoration effort will cost me about $500-$600 including all coatings, a new mast a new rec sail ($169.00 with window, but not class legal) and new deck hardware, halyards and sheets. If my fish ends up being not class legal, then so be it (especially with the modular, gimbal-mounted wet-bar). Not looking to win any regattas, I just want to avoid the "regrettas".

    I have found excellent quality rubrail by Salisbury rubber which fits beautifully and looks sharp on my metal-railed fish and shouldn't add significant discomfort to the back of my legs when hiking out. It's pretty expensive and adds some weight, but a very worthwhile investment to me.

    In terms of the mast sleeve, I guess I'll try without it at first and take it from there to see if I really need it.
     
  11. DanB

    DanB Crabber

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    Thanks for that update.

    I read a comment in a yachting forum lately that gives perspective. It went something like, the sailboat racing class officials are concerned with your pleasure craft about as much as the International Olympic Committee is concerned with your daily exercise routine.
     
  12. jsdeimel

    jsdeimel Member

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    "I'm first sealing the entire hull with the Interlux 2000E epoxy barrier system"


    I'm at a lost as to why your doing this. Is the boat staying on a mooring for the year? + the magic platelets in it are nothing more than talc. Buy a gallon of Ve resin and some baby powder and save a mint.
     
  13. Smilin_Beard

    Smilin_Beard New Member

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    Fullkeels,
    Intstead of sealing it have you thought about putting styrofoam in the mast. That is what mine has. I've flipped it a number of times for practice in a shallow bay and no problems with the boat going turtle
    SB
     
  14. fullkeels

    fullkeels New Member

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    As far as the barrier coating is concerned, I happen to have some unopened 2000E thats only about 16 months old which should be enough for the job. I've used it extensively over the last ten years on other restoration projects with excellent results except when applying it underneath alkyd enamel. The condition of my fishes skin under a magnifying glass resembles a topographic map of the Himalayas even after extensive cleaning and sanding. I'm sure there is a range of products which would suffice. I like vinylester too, but I personally have had better luck with epoxy. 2000E is very tough stuff. On a test panel years ago I was quite difficult to dig into it with a moderately blunted nail.

    As far as the sailboat racing class officials and the International Olympic Commitee you mentioned, who are they?
     
  15. fullkeels

    fullkeels New Member

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    As far as the barrier coating is concerned, I happen to have some unopened 2000E thats only about 16 months old which should be enough for the job. I've used it extensively over the last ten years on other restoration projects with excellent results except when applying it underneath alkyd enamel. The condition of my fishes skin under a magnifying glass resembles a topographic map of the Himalayas even after extensive cleaning and sanding. I'm sure there is a range of products which would suffice. I like vinylester too, but I personally have had better luck with epoxy. 2000E is very tough stuff. On a test panel years ago I was quite difficult to dig into it with a moderately blunted nail.

    As far as the sailboat racing class officials and the International Olympic Commitee you mentioned, who are they?
     
  16. mike4947

    mike4947 Member

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    As for the "class officials" here's the link for ours: http://www.sunfishclass.org/ and the "National organization for sailing overall": http://www.ussailing.org/
    Neither of which means a hill of beans if you don't participate in organized racing.

    As an FYI adding foam to a mast does NOTHING for it's ability to prevent turtling. Air itself is the best flotation device and filling the mast with foam only helps if the mast leaks enough to fill with water AND if their is foam and water gets in it will help trap the water thus reducing it's foliation ability.
    Turtle prevention is best accomplished by added "external foliation". We usually use a gallon plastic milk jug tied to the top of the upper spar or mast head.

    And I do agree that the epoxy barrier system, while really cost prohibitive if you don't already have it, is an excellent coating for light fairing and moisture barrier for the polyester hull material of the Sunfish.
     
  17. fullkeels

    fullkeels New Member

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    Thanks for the info Mike. I have previously perused the class rules, etc. to note the legal mods to a fish. Frankly, I'm a little surprised that only one "pump" per wave is allowed (subject to apparent variations in enforcement from regatta to regatta). I would think from a purely athletic perspective that pumping, ooching and sculling would be aggresively encouraged in such a small boat to feature the vessel's planing abilities and strong, fit, smart skippers. If deep in the annals of small, one-design racing it was decided that the difference should lie in the sailor and not the vessel, then wouldn't kinetics be an incumbent element in that goal? I'm not at all knocking the current system, all I'm saying is that I think it would be more fun (at the very least from a spectator viewpoint) if at least one more race was added to the schedule at some regattas with full kinetics.

    Didn't mean to ramble. Back to the mast, I've read about the ol' milk jug in another thread, and I'm thinking that given the waters where I'll be sailing my fish (8 feet average depth), I will definitely need some form of turtle rebuff self-help kit. The bay bottom in my area is mostly mud and lettuce-type seaweed with some hard sand here and there. So the possibility of turtling and burying and/or damaging the mast is very real. I plan on practicing recovering from turtle at least a few times dockside in deep enough water, but when I go out sailing I'll rig something up there. Thanks.
     
  18. Wavedancer

    Wavedancer Upside down? Staff Member

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    Kinetics such as (repeated) pumping etc. are prohibited not by the class rules but by Rule 42 (Propulsion) of The Racing Rules of Sailing. This topic has been a bone of contention, especially in the Laser and Finn classes. From what I have read, the Finn class will allow repeated pumping under certain high wind conditions; a flag will be raised to signal the sailors and the SIs will have to describe the override of rules 42.2(a) and 42.3(c).
    I won't go any further off-topic, but it's my impression that most Sunfish racers accept the current rule(s) regarding kinetics.
     
  19. fullkeels

    fullkeels New Member

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    I can surely understand the contention in the Finn and Laser classes about kinetics. My contention is that some racers sneak in extra kinetics in such a way that enables them to get away with it sometimes. If all kinetics are allowed for certain classes, I think enforcement would be more uniform. In your opinion, what do you think the justification is for the yacht racing rule as it currently stands? Makes no sense to me whatsoever. Maybe I'm looking at it from the wrong perspective.
     
  20. Kevin Pierce

    Kevin Pierce New Member

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    Best tip I ever received for sealing the mast came from Sunfish champ Jeff Linton: open the mast by removing the plastic top and bottom; remove and discard the corks; replace each cork with a racquetball; reattach plastic top and bottom.

    Racquetball size is perfect, as is the seal.

    Kevin Pierce
     

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