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Thread: laminating finished dimensional lumber

  1. #36
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    Default Re: laminating finished dimensional lumber

    Anyone ever had a scarph or a lam fail from too much epoxy?
    Anyone ever had a hard spot from too much epoxy?
    Anyone ever had sheer failure due to too much epoxy?
    or didja read it inna book ?

  2. #37
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by dalekidd View Post
    Plans call for 2" diameter max on the yard tapering to the ends.
    but do plans call for pine ?
    we jiggle sizes of things as we jiggle wood species...at least I do

  3. #38
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by wizbang 13 View Post
    but do plans call for pine ?
    we jiggle sizes of things as we jiggle wood species...at least I do
    Clint uses spruce for his yard in his kits. Not readily available so going to use the pine. I was able to find some Douglas Fir from a bowling alley that was being dismantled but it's 100 miles away and I've run out, used what I bought for my main and mizzen masts. It had fairly tight grain. This pine does not. We'll see how it works. I'm just a poor ol' "neophyte" trying to build a boat on a budget.

  4. #39
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    Default Re: laminating finished dimensional lumber

    Then, for pine, one might make the spar a bit bigger.
    But "pine" is many different things.
    I'm just saying we need not be slaves to designed scantlings.
    bruce

  5. #40
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    Default Re: laminating finished dimensional lumber

    This may be a "drift" from the topic, and dumb questions.
    The original thread stated lumberyard 1x stock, with [3] ply lamination.
    Lumberyard stock normally comes with some bow. How are boards orientated for lamination?
    The stock is probably plain cut, so growth rings may be present. Is there a preferred orientation for lamination?
    Would using a larger width board ripped to desired width(s) be advantageous?
    Thanks.

  6. #41
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by dalekidd View Post
    Clint uses spruce for his yard in his kits. Not readily available so going to use the pine. I was able to find some Douglas Fir from a bowling alley that was being dismantled but it's 100 miles away and I've run out, used what I bought for my main and mizzen masts. It had fairly tight grain. This pine does not. We'll see how it works. I'm just a poor ol' "neophyte" trying to build a boat on a budget.
    Firstly, I think that this thread has gotten a bit out of hand, to the point that we old pharts may be bulldozing a neophyte with TMI.

    Secondly, to continue bulldozing, I would like to address the spruce vs. pine debate. Using data from The Encyclopedia of Wood, white spruce is 5% heavier than white pine, has a 6.5% higher modulus of rupture and is 10% stiffer (modulus of elasticity), and is 3% less likely to shear along the grain than white pine. These are pretty small differences.

    Finally, dalekidd, go ahead and make your spars out of pine. If you are really worried about the differences between spruce and pine, make your spars 10% greater in diameter - 2-3/16 inches instead of 2 inches. The bottom line is if you build the spar to spec out of pine, and you manage to break it, it won't be the end of the world nor a financial disaster. You will be able to build a new one in a few evenings for maybe $25 - $30 and not likely lose a weekend of sailing because of it.
    Hope for the best, but plan for the worst.

  7. #42
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by Gib Etheridge View Post
    Focus on the good side David, it gave me a chance to show off how I get all the girls, well, that and I take a shower once every week without fail.
    Girls eh? And 'all' the girls, no less!!

    I know you're Canahoodian... and may not realize this... but cute girl coyotes, deer, sea otters, elk, and brown bears don't really count.
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  8. #43
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    Default Re: laminating finished dimensional lumber

    Just saying in case anyone is ever in a complete pickle and needs a new yard or boom "by tomorrow"...

    Your local DIY centres sell handrail banisters. About 2 1/4 inches diameter (54mm) x 10ft and have a flat on one side (perfect for fittings). Clear and factory straight about the length and diameter needed usually...your already more than half way there.

    Never used one, but just saying...there's potential there in the 'stair rail section' last time I was taking a look, for softwood small boat yards and booms or yacht tender masts. The ones here were tight grain too when I looked at 'em and were clearly using the better clear stuff as a handrail needs. I really couldn't see a catch. You could saw it in 'alf end for end then rout out the core section either side of the halyard attachment region, taper the end(s) and have a pretty light deluxe spar for not much more effort. They're sitting in every builders merchants.

    A 10ft/ 3m section - they are Scandinavian redwood here - is just £20 online (UK). A bit more in a store. I think my Sitka Spruce spars worked out about 3x that each. Good stuff though Sitka Spruce is. Must be similar stuff in the USA - probably longer sections as you have bigger houses! See what they got next time your in there.

    Last edited by Edward Pearson; 05-13-2021 at 12:44 PM.

  9. #44
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by David G View Post
    Girls eh? And 'all' the girls, no less!!

    I know you're Canahoodian... and may not realize this... but cute girl coyotes, deer, sea otters, elk, and brown bears don't really count.
    Beavers count.

  10. #45
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by mmd View Post
    Firstly, I think that this thread has gotten a bit out of hand, to the point that we old pharts may be bulldozing a neophyte with TMI.

    Secondly, to continue bulldozing, I would like to address the spruce vs. pine debate. Using data from The Encyclopedia of Wood, white spruce is 5% heavier than white pine, has a 6.5% higher modulus of rupture and is 10% stiffer (modulus of elasticity), and is 3% less likely to shear along the grain than white pine. These are pretty small differences.

    Finally, dalekidd, go ahead and make your spars out of pine. If you are really worried about the differences between spruce and pine, make your spars 10% greater in diameter - 2-3/16 inches instead of 2 inches. The bottom line is if you build the spar to spec out of pine, and you manage to break it, it won't be the end of the world nor a financial disaster. You will be able to build a new one in a few evenings for maybe $25 - $30 and not likely lose a weekend of sailing because of it.
    Our boy there is in Georgia, where White Pine is not very common.

    Try the numbers for Yellow Pine.
    Rattling the teacups.

  11. #46
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by oznabrag View Post
    Our boy there is in Georgia, where White Pine is not very common.

    Try the numbers for Yellow Pine.
    There seems to be four species grown in the SE USA that are called 'yellow pine' - longleaf pine, shortleaf pine, slash pine, or loblolly pine.


    longleaf: specific gravity = 0.56; mod. of rupture = 11,500 psi; mod of elasticity = 1.78 Mpsi; sheer parallel to grain = 1,275 psi

    shortleaf: specific gravity = 0.49; mod. of rupture = 10,250 psi; mod of elasticity = 1.57 Mpsi; sheer parallel to grain = 1,150 psi

    slash: specific gravity = 0.56; mod. of rupture = 12,500 psi; mod of elasticity = 1.75 Mpsi; sheer parallel to grain = 1,320 psi

    loblolly: specific gravity = 0.49; mod. of rupture = 10,050 psi; mod of elasticity = 1.59 Mpsi; sheer parallel to grain = 1,125 psi

    white spruce: specific gravity = 0.38; mod. of rupture = 7,700 psi; mod of elasticity = 1.21 Mpsi; sheer parallel to grain = 885 psi


    Interesting to note that all of these pines are heavier than white spruce, are stiffer, and less likely to shear or rupture. The caveat would be that it depends on the tightness of the annual rings; plantation-grown pine tends to have widely-spaced annual rings which greatly reduces the rupture and shear strengths of the timber. If planks are from plantation-grown pines, the mechanical properties listed above (other than SG) can be almost halved.
    Hope for the best, but plan for the worst.

  12. #47
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by oznabrag View Post
    Our boy there is in Georgia, where White Pine is not very common.

    Try the numbers for Yellow Pine.
    It's not yellow pine. I bought what Lowes call "select pine". It's clear and I believe they label it SPF (spruce, pine, fir).

    I've already figured, if it breaks, make another. I don't plan on "pushing" the limits with the rig.

    And that hand rail is an idea I'd consider. I used a closet rod on my previous boat for the sprit.

  13. #48
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by Edward Pearson View Post
    Just saying in case anyone is ever in a complete pickle and needs a new yard or boom "by tomorrow"...

    Your local DIY centres sell handrail banisters. About 2 1/4 inches diameter (54mm) x 10ft and have a flat on one side (perfect for fittings). Clear and factory straight about the length and diameter needed usually...your already more than half way there.

    Never used one, but just saying...there's potential there in the 'stair rail section' last time I was taking a look, for softwood small boat yards and booms or yacht tender masts. The ones here were tight grain too when I looked at 'em and were clearly using the better clear stuff as a handrail needs. I really couldn't see a catch. You could saw it in 'alf end for end then rout out the core section either side of the halyard attachment region, taper the end(s) and have a pretty light deluxe spar for not much more effort. They're sitting in every builders merchants.

    A 10ft/ 3m section - they are Scandinavian redwood here - is just £20 online (UK). A bit more in a store. I think my Sitka Spruce spars worked out about 3x that each. Good stuff though Sitka Spruce is. Must be similar stuff in the USA - probably longer sections as you have bigger houses! See what they got next time your in there.
    A bit more OT - but someone, many years ago, used a piece of this (though it was oak) to sister a broken frame - so they truly are multi-use!
    "If it ain't broke, you're not trying." - Red Green

  14. #49
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by oznabrag View Post
    Our boy there is in Georgia, where White Pine is not very common.

    Try the numbers for Yellow Pine.
    But if he's talking about select pine in big box stores, with not a very tight grain, then I suspect he's talking about NZ-grown radiata pine. Available in up to 12' lengths around here, perfectly clear with absolutely no knots. I build my hull from it. It's very pleasant to work with, and I imagine it's fine for a trailer-sailed boat like mine. Probably the cheapest knot-free wood you can get.

    Tom
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  15. #50
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by wizbang 13 View Post
    I rough the beejeebus outta lams that are important, like spars.
    I'm tawkin dragging a sharp sawzall blade .
    I rarely pre coat.For more time to bite, use slower hardener.
    I suspect this is the best advice. The advice "not to clamp too tight" seems to make sense, but in practice it becomes rather difficult due to the curve one is often making. for many pieces. For spars of course, it makes sense. I do precoat with unthinned epoxy for critical pieces, but typically just rely on 60 grit sand pads to rough them up

  16. #51
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by Hugh Conway View Post
    Radiata is a menards thing, other places use mystery spf.

    I made a pole for poling a canoe from banister stock. Not bad, but flexier than some alternatives
    Lowes also carries radiata in a few different forms:

    https://www.lowes.com/pl/Radiata-pin...ent=4294508716

    Tom
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  17. #52
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    Default Re: laminating finished dimensional lumber

    I am coming into this conversation quite late, but I would not use lumberyard radiata pine for anything on a boat.

    A builder put some radiata pine trim on my house 8 years ago, and it is junk. It is very soft, very weak, and not at all rot resistant.
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  18. #53
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by UCanoe_2 View Post
    I am coming into this conversation quite late, but I would not use lumberyard radiata pine for anything on a boat.

    A builder put some radiata pine trim on my house 8 years ago, and it is junk. It is very soft, very weak, and not at all rot resistant.
    On the other hand, the hull and thwarts of this boat are radiata pine and I'd say it's not exactly junk...

    DSCN3310 cropped.jpg

    Soft?

    Western Red Cedar: 310 foot-pounds Janka hardness; Radiata: 710 (more than twice as hard?)

    Weak?

    Western Red Cedar: 4,650 foot-pounds/sq inch crushing strength; Radiata: 6,030 foot-pounds/sq inch

    Rot resistance?

    Yes, not super rot resistant. Neither is occume. Both are fine for trailer boats.

    Radiata is also remarkably knot-free, and glues well. And is inexpensive--I probably spent about $400 total for the pine in that boat.

    Source for the above (radiata data)

    Source (WRC data)
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  19. #54
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    Default Re: laminating finished dimensional lumber

    Nice looking data, Tom, and I'm sure it's from a reliable source. But where does one buy the good stuff?
    "George Washington as a boy
    was ignorant of the commonest
    accomplishments of youth.
    He could not even lie."

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  20. #55
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    Default Re: laminating finished dimensional lumber

    Well, I was a bit surprised by that data myself, as radiata does seem to have a very negative reputation on the Forum. So I looked it up. It doesn't seem bad other than potential rot issues, which probably matter less with trailer-sailed boats that are stored dry.

    Around Wisconsin/Minnesota, you can buy select grade (absolutely knot-free) radiata in Menards or Lowes (big-box home improvement stores). Grain runout can be bad, but by picking carefully you can avoid that problem. It's available up to 8" wide, maybe wider, and in lengths up to 12'.

    Tom
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  21. #56
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    Default Re: laminating finished dimensional lumber

    Tom, do you have data on the shear strength parallel to the grain? That is a critical consideration.
    Hope for the best, but plan for the worst.

  22. #57
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    Default Re: laminating finished dimensional lumber

    Well, it looks like for shear strength parallel to grain, Western Red Cedar has 5.3 MPa, Douglas-Fir has 6.2 MPa and up.

    Source

    Though it seems hard to believe, THIS SOURCE has radiata pine at 16 MPa for shear strength parallel to grain. (Poplar is listed about the same)

    Can that really be accurate? Seems highly doubtful to me.

    Tom
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  23. #58
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by WI-Tom View Post
    Well, it looks like for shear strength parallel to grain, Western Red Cedar has 5.3 MPa, Douglas-Fir has 6.2 MPa and up.

    Source

    Though it seems hard to believe, THIS SOURCE has radiata pine at 16 MPa for shear strength parallel to grain. (Poplar is listed about the same)

    Can that really be accurate? Seems highly doubtful to me.

    Tom
    I've split offcuts of both WRC and Radiata for firewood. Radiata is a lot harder to split than WRC.
    There is nothing quite as permanent as a good temporary repair.

  24. #59
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    Default Re: laminating finished dimensional lumber

    I’m pretty sure the Monterey Pine in my back yard split far differently than the Radiata (Monterey Pine) Menards sells. What are the numbers from?

    Menards will sell you up to 1”*12”*12’ nominal in store and up to 1”*8”*16’ nominal on special order. It’s not cheap, but it’s clear and you can se what you get. Excepting some of it will warp to heaven.

  25. #60
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by Hugh Conway View Post
    I’m pretty sure the Monterey Pine in my back yard split far differently than the Radiata (Monterey Pine) Menards sells. What are the numbers from?
    Well, the links are there...

    It looks like a research paper studying the effects of injecting some type of resin into various types of wood. Seems like the resin-treated wood shows significantly improved strength characteristics (as in, a 38% increase in shear strength parallel to grain, I think). I don't know how reliable it is.

    Quote Originally Posted by Hugh Conway View Post
    Menards will sell you up to 1”*12”*12’ nominal in store and up to 1”*8”*16’ nominal on special order. It’s not cheap, but it’s clear and you can se what you get. Excepting some of it will warp to heaven.
    I haven't had any trouble with Menards select radiata warping. I have had standard boards warp some when left untreated. I've never bothered to order long lengths, as I want to see what I'm buying first.

    Tom
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  26. #61
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    Default Re: laminating finished dimensional lumber

    Quote Originally Posted by mmd View Post
    There seems to be four species grown in the SE USA that are called 'yellow pine' - longleaf pine, shortleaf pine, slash pine, or loblolly pine.


    longleaf: specific gravity = 0.56; mod. of rupture = 11,500 psi; mod of elasticity = 1.78 Mpsi; sheer parallel to grain = 1,275 psi

    shortleaf: specific gravity = 0.49; mod. of rupture = 10,250 psi; mod of elasticity = 1.57 Mpsi; sheer parallel to grain = 1,150 psi

    slash: specific gravity = 0.56; mod. of rupture = 12,500 psi; mod of elasticity = 1.75 Mpsi; sheer parallel to grain = 1,320 psi

    loblolly: specific gravity = 0.49; mod. of rupture = 10,050 psi; mod of elasticity = 1.59 Mpsi; sheer parallel to grain = 1,125 psi

    white spruce: specific gravity = 0.38; mod. of rupture = 7,700 psi; mod of elasticity = 1.21 Mpsi; sheer parallel to grain = 885 psi


    Interesting to note that all of these pines are heavier than white spruce, are stiffer, and less likely to shear or rupture. The caveat would be that it depends on the tightness of the annual rings; plantation-grown pine tends to have widely-spaced annual rings which greatly reduces the rupture and shear strengths of the timber. If planks are from plantation-grown pines, the mechanical properties listed above (other than SG) can be almost halved.
    I wanted to come back to this. One source I found--I don't know how reliable it is--lists radiata pine at 2,320 psi for shear strength parallel to grain. That significantly outperforms anything on your list, which makes me skeptical.

    Even if we halve that value to account for plantation growth and wide growth rings, that makes radiata compare quite well to other pines. And THIS SOURCE contains an interesting observation on p. 32:

    This is encouraging for radiata pine species, as it meansthat larger log volume does not result in less log stiffness under the same growthconditions (same harvesting age, same location and same environment).
    That seems to suggest that wider growth rings of plantation-grown radiata (which it all is, pretty much) do NOT cause a loss of stiffness. Does that mean that there may be less loss of rupture and shear strengths as well? I am in no way knowledgeable enough to make a guess.

    But even with the numbers halved, radiata seems to be, at the very least, competitive with other pines, and is perhaps no more rot-prone than occume; so, why does it have such a bad reputation on this forum? The select grade plantation-grown radiata is really pleasant to work with, comes in 12" widths and 12' lengths with absolutely no knots, and is relatively inexpensive. Am I missing some kind of serious drawback that's more obvious to those who know more?

    Tom
    You don't have to be prepared as long as you're willing to suffer the consequences.

    www.tompamperin.com

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