Wooden mast building

Discussion in 'Sailboats' started by Gaffers, Dec 30, 2009.

  1. ancient kayaker
    Joined: Aug 2006
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    ancient kayaker aka Terry Haines

    Strongly disagree! And you won't stop us going on and on about it anyway:)

    Epoxy encapsulation will stop water from moving from one place to another. It can stop it getting in, but once it gets in, through a crack perhaps, it will stop it getting out again ...

    Don't forget to rinse the inside of a hollow mast ...
     
  2. Luckless
    Joined: Mar 2009
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    Luckless Senior Member

    Go down to the supermarket and find some dried fruit. See how long it takes to rot if you keep it well sealed.
     
  3. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Brent, you are misinformed about epoxy, likely from others that are equally misinformed and disseminating lousy information. The amount of surface penetration is irrelevant to the waterproofness of an epoxy encapsulated piece.

    You're under some sort of false impression that the wood inside an encapsulated piece will rot. It can't and you are smart enough to know why. What does rot need to thrive? Eliminate any part of the three things it needs and what happens? Encapsulated wood does precisely this and rot can't form, can't thrive, literally can't live. So, the penetration argument is moot. This has been born out in test after test and through decades of in the field use, across several industries other then marine.

    Actually, urea formaldehyde adhesives have worked quite well, but they have draw backs, just like everything. It is more temperature sensitive than most typical marine laminating epoxy formulations, not less. In fact you can get epoxy formulations tailored to specific temperature requirements, where you're pretty much screwed with the formaldehyde glues. Secondly, the clamping pressures needed for successful joints with these glues can be difficult to say the least, particularly in the field with repairs. Lets not mention the glue line colors of these adhesives.

    I'm sorry your perfectionist friends had difficulties, but given they likely paid attention to the misinformed folks such as yourself, it's not a surprise they had problems. This isn't unusual and unfortunately is a common problem. This is because of lots of stupid information, was put out by a few formulators that didn't know what they were talking about (Smith Brothers being one). Once someone tested their advertising hype, the truth came out and now there's a fair bit of understandable confusion. In fact, these products that once where the cat's meow to waterproof surfaces, are now used to plastize surfaces before real epoxy is applied or they're used solo, to permit/control moisture gain in structures dependant on swelling to work (plank seams for example).

    I'm not sure what you're issue is with epoxy, but clearly you are in the minority. Epoxy formulators are popping up all over the world, but formaldehyde glue makers seem to be dieing off. In fact epoxy is wholesale replacing most adhesives and many mechanical fastenings as well. Those lead anchor shields are no longer preferred for hanger or stem bolt installations, but epoxy bonded holes work much better. They have to be done properly, just like the old anchor shields or things will fail, like the concrete roof slabs on the Big Dig in Boston last year, but this is pretty much true of most things.
     
  4. 58ketch
    Joined: Sep 2009
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    58ketch Junior Member

    Not too very long ago..a few years back..I built a simple box/laminated tapered mast for a Hampton for a client who wanted internal halyards...while I thought that was overkill for the boat (the halyards really aren't THAT big a deal in a Hampton, anyway) what we did was champfer off the corners of each member and epoxy coat them internally as best we could and, then laid in a section of 1/2 pvc pipe with a gasket at the head.
    While I've no way of knowing what the inside looks like now, I do know that he has no line wear issues beyond "usual and typical" for internal halyards and has no signs of rot that are visible.
    We left a weep hole just above the step and it seems to drain adequately..fwiw.
     
  5. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    According to Brent, you're "eventually" doomed. I'll suggest that what you did is a common technique and that it works well. Drainage holes getting plugged up are the biggest problem with hollow masts, not the fears Brent has. These holes get plugged because as lines run through their sheaves, very small amount of sand, dirt and dust get rubbed off and eventually find their way to the bottom of the spar, where they collect and eventually plug the drain holes. When I make new spars I make removable plugs, that have the weep holes in them. From time to time, you can remove these plugs, clean out any accumulated debris and reinstall them.
     
  6. Brent Swain
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    Brent Swain Member

    I've used formaldehyde glue in the dead of winter, then put the glued pieces in a bucket of water for several more years with no delam or other problems. I've seen epoxy laminated parts fall apart, in a workshop, without having seen any outside conditions. A commercially made a laminated bow I had, laminated with epoxy , made by Hoyt Archery, fell apart.
    A wooden mast has a lot of fittings bolted to it, which can enable water to come in . Most of the time it is well enough sealed, but sometimes seals fail , just like they do in commercially made "Waterproof " autopilots which if left outside, all eventually fill up with water. You say some things on a boat can be made 100% failproof watertight? ******** . I've been cruising too long to still be that naive. Some obviously haven't
     
  7. Luckless
    Joined: Mar 2009
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    Luckless Senior Member

    And there was a big complaint at my school awhile back about the expense they went through to put in new counters and the complaint of the use of a formaldehyde glue used. All the counter tops were buckling and pulling apart.

    Do you have a point? Do you have data?
     
  8. apex1

    apex1 Guest

    Oh Brent, Brent,

    I have seen a house burning down completely. The entire family killed in their beds.
    Brickwalls cracked from heat, a refrigerator, tall as a man, was molten to the size of a shoebox. Nothing survived the fire. Except a bundle of old magazines (paper!) and a little doll! The doll still had the artificial hair and a red little dress. The most bizarre picture I can remember.

    Must I assume now, that plastic dolls are less vulnerable than humans? Paper is the better material for making refrigerators?

    Formaldehyde glue.........you´re kidding.
     
  9. 58ketch
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    58ketch Junior Member

    ;) ....opinions are like, well, you know....

    I've been a woodworker for over 40 years and in that time I have seen failures in hide glue, epoxy , resin and chemical glues. I have never seen a failure that could be attributed entirely to the adhesive, though. "Operator error". inadequate or uneven clamping, extreme heat or cold either during laminating or afterward, etc. have ALWAYS been present.
    NOTHING is perfect 100% of the time nor is any process BUT, I can honestly say that with the possible exception of water and flour paste I have the utmost confidence in most adhesives and, since the advent of epoxy, even more. The ONLY adhesive I trust beyond epoxy (where applicable/ pick your brand) is Resorcinol.
    Do I think that really matters? No, I have found all of the adhesives when used as directed to be most forgiving and durable in competent hands...the latter being of the UTMOST importance.
    As for my little Hampton mast...I'll wager it outlives me.;)
     
  10. ancient kayaker
    Joined: Aug 2006
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    ancient kayaker aka Terry Haines

    Gaffers: sorry about this; don't worry - the thread will die of old age eventually. Hope you got what you wanted. Happy New Year!
     

  11. Brent Swain
    Joined: Mar 2002
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    Brent Swain Member

    I have only 40 years experience, much of it offshore, in all kinds of conditions , using both.
     
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