is there "marine grade" lumber?

Discussion in 'Materials' started by jumpinjackflash, Jul 17, 2014.

  1. jumpinjackflash
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    jumpinjackflash Junior Member

    so there's relatively cheap/free white pine available around my area, is this usable in planked/lapstrake boat construction?
     
  2. gonzo
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    gonzo Senior Member

    Yes it is. Preferably you want either clear or only small tight knots. Larger knots can be repaired with an graving piece glued in.
     
  3. 7228sedan
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    7228sedan Senior Member

    are you looking to coat it in fiberglass or epoxy? Any wood can be used it's a matter of how well it will be encapsulated. softer woods are more susceptible to rot.
     
  4. jumpinjackflash
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    jumpinjackflash Junior Member

    right on, so why exactly is plywood considered the cheapest method of construction then? I don't know if it's just where I live, but there's a ton of cheap and even free lumber available.

    I'm not sure about fiberglass, I do like the look of varnished wood
     
  5. gonzo
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    gonzo Senior Member

    Softer woods like aromatic cedar are one of the most resistant to rot. The hardness and rot resistance are not related. Plywood may or may not be cheaper than planked with solid wood. It depends on the design and the type of wood or plywood you are using. Plywood is usually much faster to plank. If you can get free pine, you won't find plywood that can compete in price. There is no requirement to use epoxy or fiberglass over it. A good quality exterior house paint will work.
     
  6. Petros
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    Petros Senior Member

    I do not think plywood is the cheapest way to build a boat, but it is one of the fastest ways for a conventional hull. And perhaps cheaper if you buy only from a "specialty" wood store.

    Salvaged plank on frame would be cheaper, but way more labor intensive. I have also built many smaller skin-on-frame hulls (kayaks, canoes and dingy sailors) from all salvaged lumber, very fast and for well under $100 (the fabric is the most expensive part!). Skin-on-frame is the cheapest way to go hands down, very fast to make nice fair hull shapes as well, and very light. My wife's 16' cedar skin-on-frame kayak only weighs 19 lbs (lighter than the very expenisve carbon sea kayak hulls).

    Almost anything and every thing has been used to make boat hulls, from bamboo to hardwoods, steel, aluminum and even concrete. There is no limit to what a hull can be made from.

    Most any reasonably strong, fairly clear lumber can be used to make wood boats. If it has good rot resistance even better, but not necessary if it will be stored out of the water and out of the weather.

    I have used lumber from big box store lumber yards, but you have to select through the stacks to find some reasonably clear pieces. the specialty lumber yards have better quality wood but you still need to select through the stacks, and expect to pay more. Than I remill them on my table saw to make stringers, gunwales, etc. selecting the better more clear pieces for the longer parts that have significant structural loads like the gunwales and keel. I know of some that even scarf joint shorter pieces, but I am not that brave and would not trust my glue joint for primary structural elements.

    Finding longer pieces to salvage is always difficult, but every once in a while someone is treating down an old barn or other large building full of clear old growth cedar or Douglas fir. if I get there in time I can get longer paces of clear lumber before they cut it up. I built my wife's kayak out of a single pace of clear cedar siding from a 100 year old barn that was torn down. I just added some Alaska yellow cedar for the steam bent ribs. You just have to keep your eyes open for opportunities to find aged old lumber to salvage. One time I drove off with a whole truck load of 100 year old clear old growth douglas fir for free, it was coming out of an old church during a remodel, they were going to haul it to the dump! I remill them on a table saw and planer. Some of this wood I have even used to make trim for my house and kitchen it was so nice. The only problem with lumber this old is you must pre-drill all of your fastener holes or you risk splitting the very dry and brittle wood.

    good luck.
     
  7. SukiSolo
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    SukiSolo Senior Member

    That, and the odd nail or screw. When I had a 100' Doug Fir planked a nail was found - unfortunately by the saw blade over 4" inside. Someone had probably put a bat box on it 20+ years ago!!. Least that was the only one.

    I try and save as much old mahogany, Honduras and Brazilian as possible now just for future repairs. A friend gave me a couple of old window frames - nice Brazilian. A couple of old dinghies where the ply had gone totally rotten (3 core) served to yield a solid 5/8"ths solid mahogany board case and some nice side benches.
     
  8. missinginaction
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    missinginaction Senior Member

    A couple of years ago I acquired a planer. It's amazing how weathered wood can be saved just by taking off a thin layer of surface. Just be careful of fasteners as others have said.
     
  9. PAR
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    PAR Yacht Designer/Builder

    There's no such thing as "marine grade lumber" though there are marine grade "wood products" such as plywood.

    The only thing that make one species more applicable over another in a solid wood decision, is the experience of the person selecting the stock. There are things you'll look for in solid wood boat pieces. This is the primary difference, though some respect for known (accepted boatbuilding) species should be understood, simply a little education is the only difference between something a cabinet maker might choose, compared to a boat builder finding acceptable.

    Jumping Jack, you'd be best advised to pick up a few books on boatbuilding. I suggest this as you've asked several very basic questions and all you need is a little knowledge. This is easy enough with some research. You can ask one question at a time in a format like this, which you will make a career out of, or you could get much of it all at once, with a few boatbuilding books. The book store here would be a good place to start.
     
  10. CloudDiver
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    CloudDiver Senior Member

    We were talking about pine in another thread, and like the others above I think its a great material depending on where you intend to use it and on what type of design. Pine is soft so for certain boats it isn't good for load bearing/structural unless you go heavy. The softness makes it easier on tools and saws which one poster pointed out saves a great deal of time in milling. On the plus side, yes its less expensive, but it also glues very well. For water proofing I like expoxy, thinned 10 percent for the first 2 coats it will penetrate deeper into the wood and you don't have to use fiberglass over it unless the design warrants it. If you like the varnished look this is still a good method, epoxy to seal and then a compatible varnish over it. You will find many examples of this method in wood boat construction books.
    In general, we all like cheap or free lumber (with careful consideration of where it will be used). Personally I really like the idea of repurposing (recycling) because its hopefully cheap and enviromentally responsible, you just have to be willing to put in the sweat equity to find it, haul it, and re-saw/mill it.
     
  11. Petros
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    Petros Senior Member

    oh yes! on any salvaged lumber it MUST be carefully inspected for old nails or screws. sometimes even raw logs will have spikes buried in them, or even barbed wire when the tree was used as a fence post. I have found however that quality modern carbide tipped saw blades usually will cut through them without issue.

    BTW, Do not buy cheap saw blades, they do not hold up and are a waste of money; the better quality ones are not only cheaper in the long run, but cut cleaner with a smaller curf, so it takes less power, and you loose less wood to saw dust. they typially cut through soft nails or screws without complaint too.

    PAR is correct, there is no such thing a Marine lumber, it is just a matter of quality of the wood (grain run-out, number and size of knots, sap pockets and other defects), and there are certain species that have traditionally been used because of their properties and availability. However, as I stated, wood boats have been made from anything and everything, from reeds and grass, to White oak and larch.

    I have found btw, that sawing your own raw logs, or even felling your own trees to get your own lumber, is a lot of work and takes time and space to season it. They may be "free" but cost you a lot of effort. I would much rather buy or salvage something larger but already milled rectangular, than ripping and planing it into the size I need, is much faster and easier than to deal with a large irregular round log. though some have done it to get what they want, and have a local mill cut it to the rough sizes they need. If you were building a large all wood boat it might be a consideration, but on the smaller dingy sailors and kayaks I have built, salvaged timbers are the way to go. Besides, in most areas there is usually enough construction and remodeling of old buildings going on you can find what you need with time and keeping your eyes open for it.
     
  12. PAR
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    PAR Yacht Designer/Builder

    CloudDiver. I'm not sure of your experience, but thinned epoxy doesn't water proof anything. Testing has clearing shown this and these old "wives tails" from the ghosts of builders past need to just die off. In fact if you apply a second thinned coat, the first has sealed the pores so now you just have an out gassing issue to contend with, as it will not penetrate the previous coating. Lastly, these same thinned epoxy tests (conducted by peer and independent firms) also proved that penetration had absolutely nothing to do with waterproofing ability. Quite the opposite was found and the quality of the coating was all that really mattered.

    Epoxy isn't like varnish, which can benefit from having the first few coats thinned. Without an understanding of the chemistry and physical attributes of the cured matrix, playing with home brews is just a guarantee that things will not be as you hoped. Under varnish, it's best to have just wood, not epoxy, at least from a maintenance point of view. You can repair and touch up varnish as required or you can repair and touch up epoxy coated varnish, it's your call. Invariably, the epoxy under the varnish causes more difficulty in this regard and since clear coatings over wood, are the most difficult to maintain, it's usually wise to keep them simple and easily repaired/touched up, etc.
     
  13. rwatson
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    rwatson Senior Member


    True - I have read several testing results, and can support Pars info
     
  14. UNCIVILIZED
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    UNCIVILIZED DIY Junkyard MadScientist

    Buehler's Backyard Boatbuilding at Amazon http://www.amazon.com/Buehlers-Back...qid=1406182053&sr=8-1&keywords=george beuhler is a good one for covering the basics of boat construction. Especially the questions about lumber, as well as the different types of planking which are available & how to reasonably best use each one.
    It's kind of a classic, or cult classic IMHO, with a lot of information in it as well as being a good read. And it also shows how to inexpensively build a boat in our overly consumer driven age.

    Old and or recycled lumber is great stuff. As to embedded metal, when in doubt, add a face shield & welder's jacket, in addition to your safety glasses when machining it. And if the wood's cheap enough/free, & you've got the time, there's nada wrong with firing up an Alaskan saw mill.
    Sometimes you can get lumber/trees from folks clearing land/demolishing old structures, prior to their building stick built homes & such. Or if you know what you're doing, offer up your tree clearing services for a price... aka Arborist.
     

  15. CloudDiver
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    CloudDiver Senior Member

    Sorry PAR, but if you are going to talk about tests that have been conducted you need to cite them, otherwise your comment is juat as invalid as my 'old wive's tales'...

    Thinning Epoxy for penetration into wood fiber depends on the viscosity of the epoxy brand you choose. I've used several types but only really remember WEST System because it is the only one that has been consistent since the first batch I mixed over 20 years ago up unitil the last batch a month ago. I've only needed to thin it 10%, and you don't let it cure between coats, obviously you need the chemical bond since once cured the mechanical bond is reduced by having once coat already sealing the wood fibers. So we arrive at the point, and in that respect I can agreee with the general statement you make that thinned epoxy does not make the wood 'more waterproof' than a single application of non-thinned epoxy. The goal is to create a stronger mechanical bond by penetrating deeper into the wood fiber, and perhaps more resistant to abrasion since the epoxy penetrates deeper.
    I've used this method on cedar strip canoes, kayaks, and Adirondack Guideboats. These boats are typically not for white-water use, but some of my crazy bearded flannel clad buddies have done just that without fear. Abrasion from rocks, portage dragging etc has on some occassions worn through the 4 oz glass layer and started to abrade the wood fiber then allowing water into the raw wood, but I never saw a full punture from heavy impact.
    In terms of the post, related to the OP's question, I made the suggestion for waterproofing wood that is softer (pine). If I was using soft pine I would take the extra steps to get deeper expoxy penetration prior to the glass layer in the event that an impact could puncture the glass and disturb the wood fibers.
    This is the way I was taught... My teacher was not an engineer or a chemist, but had 35 years of wooden boat building experience. So give people a little credit for actually doing things and not dismisssing them for 'old wives tales' in favor of lab tests (that you mention, but never cite).
    As far as out gassing... Never had a problem with it since I know not to apply epoxy to 'cold wood'. Have fun with that statement since I'm sure you'll declare that an 'old wives tale' and tell me I'm wrong and I need to go read more books, get a Master's Degree, and have a web published portfolio of at least 30 completed hulls before commenting on this forum.


     
    Last edited: Jul 24, 2014
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