How to correctly prepare pine for mast?

Discussion in 'Materials' started by laukejas, Feb 16, 2012.

  1. alan white
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    alan white Senior Member

    A solid mast is not a grown mast. A solid mast is a mast built without a hollow center. A grown mast is a mast built using a single piece of wood.
    I said solid masts are usually used, meaning historically, almost every small boat was built with a solid wood mast, glued up or one piece.
    A hollow mast is lighter by far and is superior in terms of performance and ease of raising. Obviously this is the mast to have on a performance boat, though a workboat would be more practical with a solid mast.
    I recommended a box section mast because it is simple to make, almost as light as a birdsmouth mast, and likely, with patience, within your ability to build.
    Why not a box section?
     
  2. PAR
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    PAR Yacht Designer/Builder

    Laukejas, it would be much more helpful if you told us the specific species available locally. My species data base shows well over 320 different species of pine, so you need to be a bit more specific.

    Lithuania has a proud boat building history and you also have many fine woods to select from. I'm not sure where you are located, but the coast is dotted with small boat repair shops and marinas. Spend a day visiting each and get an idea what is used. Everything from very traditional wooden, to high tech composites are being manufactured, so clearly you're not up to speed on what's available there.

    Most small craft employ a laminated solid, box section or hollow halfed section mast, unless quite small, where a hollow mast is too troublesome to build. Your boat being a cat, typically would employ the lightest method, as cats tend to be weight sensitive. On wholesome, traditionally built small craft, a solid mast is fairly common. These builds are usually quite heavy, sometimes deep, often ballasted, full bellied shapes. A heavy mast doesn't effect these types of design that much (okay it does, but it's not so important, as preformance is limited). Catamarans on the other hand, usually are more preformance oriented and also much lighter comparatively, so a hollow stick is employed.

    The problem is you have a great lack of understanding across several areas, which holds you back in regard to decision making on species, lumber utilization, construction methods, etc. Couple this with a self designed type of thing, in which you've limited hydrodynamic skills and well, you're at a disadvantage to say the least.

    You can cut your own stock if you want, but it'll take a year or two for a small tree to season out. Naturally seasoning stock information, is widely available from several sources. You''l want to debark the tree, oil it heavily if it's a species that likes to check as it dries, then cover it with a tarp. Every 3 months uncover it, re-oil it and turn it over 180 degrees, then recover and wait some more). A small diameter tree (100 mm or less) will take at least a year and a half, probably two, unless accelerated in a solar kiln.
     
  3. hoytedow
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    hoytedow Wood Butcher

    Laukejas, are you in easy reach of the coast, or are you far inland?
     
  4. troy2000
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    troy2000 Senior Member

    For cryin' out loud... ignore all this knowledgeable and well-meaning professional advice (sound as it is), and go find a tree to cut down. What's the worst that could happen? If it doesn't work out, you haven't lost much beyond your labor and your dreams.

    Wood seasons best with the bark on, and setting on stickers so the air can flow around it. Ideally, you'd season it shaded under a shed roof and over bare ground, to avoid extreme changes in humidity. Seal the ends with tar or something (even varnish or paint), to keep them from drying out faster than the rest of the piece and cracking. If you can, cut the mast during winter and let it air-dry for at least a few months, while you're building the rest of the boat. But don't get too hung up on details and proper procedure; it's just a friggen piece of wood. if it doesn't work out, go cut another one and apply what you've learned.

    Some of the advice I've read over the years also says it's better to turn the stick upside down and taper it, instead of leaving it right-side up and using the natural taper. Supposedly, that inhibits the capillary action that draws water into the wood and helps it rot. But i wouldn't even worry about that too much, if I were you. If your mast rots, go cut another one.:)
     
  5. laukejas
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    laukejas Senior Member

    Alan, sorry for confusion, I mixed up terms, and made a mistake. Now I understand, thanks. Yeah, probably that box section mast is my best bet, I looked it up, and I think I have enough tools and skill for that.

    PAR, thank you for such long explanation, I'll try to answer what I know.
    In Lithuania, most common woods are:
    Norway Spruce
    Scots Pine
    English Oak
    Silver Birch
    European Ash
    Aspen

    Well, that's pretty much it. These are trees that I would probably be able to find in most forests, but I think that only pine and spruce are available in wood stripes or planks I need that are for sale. Or that "mixed" wood.

    I am located far inland, in capital, Vilnius. I'll do my sailing northeast of there, in this lake. But my boat building will take place in Vilnius. If I would live near the sea, I would surely take a look there.
    By the way, there was one boatbuilder in Lithuania, my friend, it is he who said that from all that we have in Lithuania, pine is best for masts.

    Yes, I know that my knowledge is near to none, that's why I am here, asking and trying to learn. Good thing is, this is my second project, and I have a friend boatbuilder to advice me on hydrodynamics and design, but I don't have anyone to consult on woodwork. I tried metal mast before, but as you can see, if you watched that video, that can't be called a mast (that applies for the sail and hydrodynamics too).

    Well, you convinced me totally here. I'll go for box section mast. But now I have hard time finding proper wood strips, since, as I said before, shops don't offer a lot, and I don't have equipment to make these strips myself, as in the links you provided.
     
  6. bntii
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    bntii Senior Member

  7. laukejas
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    laukejas Senior Member

    That's the video, yes. I know, it looks horrible, but that the first crude effort with near-zero knowledge and EXTREMELY limited budget. That raft is to be reconstructed into catamaran. Then only thing that will remain is the deck. Two PVC pipes will act as gondolas (proven design), the mast will be replaced with the one we are now discussing, and I'll make two tyvek sails (already working on them).
     
  8. hoytedow
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    hoytedow Wood Butcher

    Have fun with it. Everyone here without exception started with zero knowledge.

    Enjoy life.
     
  9. laukejas
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    laukejas Senior Member

    Okay, so thank you all for your help, sailors. You have provided a lot of very useful information, I've finally decided to build box section mast, while before I didn't even know there is such design. Thank you all again, and good winds to you.
     
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  10. laukejas
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    laukejas Senior Member

    Hello again,

    I'm now looking for a good glue to make this mast. This article recommends Phenolic Resin, but I can't find any glue in Lithuania with this material. Also, I can't even translate it, since no vocabulary has these technical terms.

    Could anyone name several brand names or even exact products of Phenolic Resin in Amazon or Ebay? That way, I could buy via net, or find equivalent in my country.

    Also, is that Phenolic Resin waterproof? Would it be good to use for hull (wood and plastic) in parts which are submerged underwater?
     
  11. PAR
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    PAR Yacht Designer/Builder

    You're looking for a common adhesive called resorcinol, which is a phenol formaldehyde resin. It was once quite popular, but has since been all but replaced with epoxy and polyurethanes. I have no idea what is available in your country, but you can get anything through mail order and on line purchases.

    Resorcinol is a difficult to adhesive to work with for the novice user. It requires perfectly fitted joints, lots of clamping pressure and has a small temperature "window" in which to work. This is why other adhesives are now more commonly employed.
     
  12. Petros
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    Petros Senior Member

    Laukejas,

    Great little project. You can also use Titebond II or III for a mast, less costly than epoxy or polyurethane. Actually most any waterproof glue should work okay if you also use fasteners of some type.

    You might consider if there is a local lumber mill and buy what you need directly from the mill. There are often small mills run by individuals out of their home, part time to make specialty cuts for local wood workers. Also, if you can find long enough pieces at building sites where they are tearing down old buildings you can often salvage good lumber if you pick through the wreckage carefully. I get much of my wood this way.

    Cutting your own wood is an option, but until it is seasoned it will not have much strength. So either you use it "green" and risk it failing, or you wait until it is ready to be milled.

    For such a simple boat I would not go to a lot of trouble, just see what you can find to use for a mast. You have to put stays on it to brace it of course, and the Tyvek sail works great, I have built a number of them using duck tape.

    You might consider gathering materials for a better all wood boat for next year, take what you learn on this one and build a better one for next summer.

    Good luck.
     
  13. Manie B
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    Manie B Senior Member

    This is from

    http://www.duckworksmagazine.com/06/howto/birdsmouth/index.htm

    any idea why they are so against epoxy
    doesn't make sense to me?

    surely you can glue up with epoxy then coat the entire outside with epoxy and then use a good varnish as UV protection or simply paint white ??
     
  14. hoytedow
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    hoytedow Wood Butcher

    Both can be used but solid weighs more without adding appreciably more strength. Hollow is better and easier on the back.
     

  15. PAR
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    PAR Yacht Designer/Builder

    Manie, because it's an article written by Roy McBride of South Africa, who is keen on PVA's, but not up on it's physical properties, particularly compared to epoxy. He quickly lists the WBP tests it passes, but had he preformed some of his own tests, he'd find that it just barely passes and creeps badly under load, especially in a moist environment (guess where boats like to live). PVA's shouldn't be trusted in a spar and although Roy brags about his big schooner spars, PVA's creep will ultimately let him down. Not even the PVA manufactures recommend it for structural applications. With a low stress gaff rigged schooner, he's probably in luck, but try it on a something with some load or a free standing rig and you'll quickly pay the price for low balling the adhesive. There are a lot of folks out there that just can't let go of old biases and insist epoxy is a "fad", such as Larry Pardey for example. Simply looking up the physical attributes of each will solve any debate.
     
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