using regular old dimensional lumber

Discussion in 'Boatbuilding' started by p35bhp09, Nov 7, 2009.

  1. p35bhp09
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    p35bhp09 New Member

    I have spent the last hour using the search feature yet have not found the answer to my question. I have just received my plans to build the Jolly Roger from Glen L. The plans call for dimensional 2"x6"s for the frames. Is there a considerable difference between a Doug fir 2x6 from Home Depot or Lowes and a piece of doug fir stock that I can order from a small lumber store sight unseen? I do realize that I would have to do a lot of sorting through the stacks but after all is said and done is there that much of a difference?
  2. marshmat
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    marshmat Senior Member

    A comparable grade of the same species, in a given geographic area, should be fairly similar regardless of who you buy it from.

    However, you will likely find that at a place like HD or Lowes, most of what's available will be relatively poor quality, plain sawn lumber, often warped and/or knotty. Virtually everything these guys sell ends up as a wall or a deck, so they don't have to be too picky. You might have a better chance of finding nice, straight quarter-sawn stock at a place that only deals with lumber. Mention that you're a wooden boat person, and you're looking for good frame and/or planking stock, and you might get some extra leeway (and help) with picking through the piles- many folks have reported that sawmill owners tend to love wooden boats.

    Some people eventually develop relationships with trusted suppliers.... but for dealing with any new supplier, I wouldn't even think about ordering sight unseen.
  3. alan white
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    alan white Senior Member

    I've used Home Depot 4 x 4s but as said, one must go through the stack. Certainly, the entire reason for the designer to specify 2 x 6s was to allow you to purchase your framing stock from just about any home center or lumber yard.
    Now, with that 1 1/2 x 5 1/2" dimension specified, you can imagine the designer realized that hand-picked construction grade lumber would be adaquate.
    The idea is that if you were going to have to order from a small lumber store, you might as well not have to be limited to that 1 1/2" x 5 1/2" dimension.
    The small lumber store will likely sell only roughsawn stock. Their clientele are furniture shops and custom woodworking shops. Hence, the wood they supply is both better quality and also more expensive, in addition to being (usually) roughsawn.
    Some of the quality difference is in the grading. Some is in the drying process, where more care (and time) is taken in the process.
    Do yourself a favor----- take advantage of the fact that your work has been made easier by a design that uses common dimensional lumber. You can always hand-pick, and don't worry about the boat falling apart. It will last a long time even if the frames are not as "perfect" as they could be.
    You'll save money, which is the whole idea, after all, and time and waste as well.
    Whenever I see a really nice 2 x in my business of house carpentry, I grab it and set it aside for boat use.
    I will say one thing. Fir 2 xs aren't available here in Maine, and spruce is. The fir is stronger but not that much stronger, and I'm sure if you can only find spruce you'll be okay. Just avoid pitch pockets and signs of internal stress (cracks and warping).
    I also use pressure-treated wood in boats, but only old stuff reclaimed from the dump or from deck debris. I have more faith is old dry stock where gluing is concerned. I like heavy stock, not light sapwood or fast growth stuff.
    I use it for a lot of tabbed-in parts, and where it is fayed to another part where rot might be a problem.
  4. Submarine Tom

    Submarine Tom Previous Member

    Being your neighbour, I'd be surprised if you found any fir 2 X 6's.

    They'll be SPF (spruce, pine, fir) but often hemlock as well. I went through

    two lifts to find 26 decent 10 foot 2 x 6's for my house boat and then coated

    them in wood preservative. They work great!

    Good luck.

  5. p35bhp09
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    p35bhp09 New Member


    I have been completely rebuilding my house here in Pendleton, Or for the last three years so the people at the Hermiston Home Depot have gotten to know me well. I very well could be mistaken ( I learned a long time ago to never say I'm 100% sure) but I believe the stacks of dimensional lumber are very often marked Doug Fir, or at least the signs are. Is there an easy way to tell the difference? I'm not trying to skimp since I have no intentions of staying tied to the dock however I work for a living and I can only divert so much discretionary cash into my boat. The hull will be Meranti marine ply as per the plans with all joint epoxied and the hull covered with at least two layers of 7oz cloth. back to the subject I'm buying lumber every week for the house (since I remodel from paycheck to paycheck) and every once in a while I find some arrow straight, knot free pieces.
  6. PAR
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    PAR Yacht Designer/Builder

    The dimensional lumber in your area of the country will often be Douglas fir, probably plantation or second growth. Douglas fir is fairly easy to recognize once you get used to looking at it, particularly compared to SPF.

    The big box stores sell lumber for the needs of home building. It's less then suitable for boat building, unless you choose wisely. By this I mean you can find some very nice stock at these places for considerably less then a specialty wood store. For example if you need 2x6's, buy 2x12's and rip them down the middle. This will give you quarter sawn material and it will be denser and likely have fewer defects, because it came from an older tree. You'll pay the same for the wood (two 2x6'x8' pieces cost about the same as one 2x12'x8')

    Separate the nice pieces from you house project. Also look for stock that you can rip and make into quarter sawn. In your area there should be dozens of small mills where you can find deals and off cuts. Make yourself a friend of these places, they can do things and get things that other places charge out the nose for.
  7. TeddyDiver
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    TeddyDiver Gollywobbler

    Some healthy knots doesn't really matter. They actually make the lumber stronger against cracking. I try to choose knots diameter < 1/3 of the thickness or <1/4 of the width, or < 1/2" which ever is the smallest.
  8. Homefront
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    Homefront Junior Member

    Here in Pa, virtually all of the commonly found framing lumber is Hem Fir.
    When I was framing houses for a large builder, perfectly straight 2x10 joists right off the pile measured 9-1/2" across. I would return to these homes to do warranty repairs where the joists had warped and twisted from drying to such an extent that doors would no longer open/close, floors had huge humps or dips in them - measuring these now completely dry sticks showed that they had shrunk to 9-1/8" across. In several cases the joists had burst downward through ceilings when internal stresses from the shrinkage became too great.
    I don't like Hem Fir - it comes to market too wet, and changes shape too much with a change in moisture content. It not only shrinks, it twists.
    You will be much happier with real Douglas Fir.
    Get a moisture meter, and sticker your lumber until it gets as dry as possible and stabilizes. Indoors would be best. If you're not going to soak (encapsulate) everything with 3 coats of epoxy as you build, then another moisture retarder, such as linseed oil, would be needed, after the glue between components had cured. Of course this assumes you will be using adhesive; if you're building using strictly conventional fastenings, then you can slather multiple coats of linseed oil, cut about 10% with turpentine, anytime you want as you go along.
    I would consider using local red oak for the frames, sawn and dried to order. I'd contact Glen-L about reducing the lumber dimensions to compensate for the added weight oak would bring, but there will also be a big gain in strength over Hem Fir.
  9. alan white
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    alan white Senior Member

    Hemfir is, of course, a family of allowable woods. Hemlock is particularly strong reacting wood, so it wants to be pinned down fast, lest it tear itself out. That said, it is amazingly strong once dried and it holds nails like no other. If the wood shrinks a lot, like the 3/8" described, it was not properly dried, which would have been evident at the time of construction.
    All that said, fir is preferable to hemlock, which should be relegated to building houses and not boats.
    Look for fir with close grain lines and quarter-sawn over the wide dimension, which may be difficult to locate. also look for pitch pockets, or plan to saw around them.
    Fir generally looks pink when sold, quickly turning orange-brown. The growth rings have darker thin divisions, while spruce and hemlock look more uniform in color and are whitish in color, with a (very) slightly darker growth ring division. The darker growth ring divisions of fir are also much harder than the pulpier wood between, enough so that sanding it requires skill to avoid waviness. This would never be a problem with spruce or hemlock.
  10. lewisboats
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    lewisboats Obsessed Member

    Note on Red Oak....not a good boatbuilding wood. Wicks up water like a straw. White oak is totally different stuff.
  11. Homefront
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    Homefront Junior Member

    No they're not the same, and white is definitely preferred for some uses.

    John Gardner recommended red as a good substitute for white, provided a proper finish was applied, which is why I elaborated on sealing with epoxy or oil. Oil with pine tar would be even better.

    I used well-epoxied red oak for frames in a 14' flat bottom fishing skiff 12 or 15 years ago. The boat lived on a trailer, had a bilge plug and a cover. It held up very well, with no rot anywhere in the 8 or so years I owned it. No doubt it would eventually go bad if the boat was left uncovered through winter, filled with leaves, etc.
  12. alan white
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    alan white Senior Member

    White oak, live oak, etc., are not expensive, just 50% more than red oak. The epoxy to protect red oak costs more than the difference. It's really a matter of availability. I'm happy that I can find white oak around here in Maine, at a cabinet shop that resells wood reasonably.
    Always try to source white oak firsat. It's worth it.
  13. gonzo
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    gonzo Senior Member

    Wherever you get your lumber from, it is worth investing in a moisture meter. The ones with pins are cheap

  14. SamSam
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    SamSam Senior Member

    Resawing a 2x12 works but sometimes releases stresses and the wood bends or warps. What works good for short, 8-10-12' lengths is to get 16-20-24' lumber and saw it in half.
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