Wood equal to or better than Douglas Fir?

Discussion in 'Materials' started by abosely, Jul 1, 2015.

  1. SukiSolo
    Joined: Dec 2012
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    SukiSolo Senior Member

    Almost surprising, no one has suggested Raspberry Jam(mmer) wood yet......;)
     
  2. Deering
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    Deering Senior Member

    Why not use marine grade plywood? Laminate beams from 1/2" meranti and you'll have strong, handsome, and reasonably light construction. For the deeper beams (if you have them) you could add lightering holes.
     
  3. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Actually, plywood isn't a good choice, because it's only 2/3's as stiff as solid lumber longitudinally and typically heavier, though it does have been cross grain strength.
     
  4. abosely
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    abosely Senior Member

    I believe I've found the wood species I'll use in lieu of D-F.

    It's Eucalyptus deglupta, commonly called Rainbow Eucalyptus. There are over a hundred different Eucalyptus subspecies and are not suitable.

    I've been talking with DR. J. B. Friday of the Hawaii Forestry Extension, University of HI Hilo about the Hawaiian grown trees.

    Plantation grown ones are less dense but they are harvested starting a 6 yrs old depending on use. As they get more mature they become denser and stronger

    Plantation grown (young trees) characteristics:

    Wt 31 lbs cu/ft
    SG .38 - .50
    Rupture 11,550
    Elastic 1,565,000
    Crushing 6780

    The ones I'll be cutting will be a 34-35 lbs and stronger than D-F in all aspects. A nice thing of them is the lumber length is only limited by the saw carriage length of 24'. So can have 22'-23' long pieces for stringers & beams, so less splices. The Albizia Lebbeck would only be around 8' logs. Will be using it for house project so can pick and choose the wood for the Narai Mk IV.

    Only thing is it's not durable against rot. But all wood will be encapsulated so that's a moot point.

    I'm pretty happy to found out about Eucalyptus deglupta and that it's readily available here. Plus can't beat the price!

    Cheers, Allen
     
  5. SukiSolo
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    SukiSolo Senior Member

    I'd enquire as to the grain run on that species. My experience of Eucalypts grown in the UK is that there is significant helical twist (of the grain) throughout the trunk. As you rightly say, there are I believe over 300 different Eucalypt types so some must have straight grain.

    The stuff I have seen, worked and split for the wood burner, is far from ideal for boat construction. It would however be close in terms of SD and strength though.
     
  6. Mr Efficiency
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    Mr Efficiency Senior Member

    Spotted Gum ( eucalyptus maculata) is as strong as all get-out, but rather dense. A popular choice for timber trawlers and the like. Also used in axe-handles etc.
     
  7. abosely
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    abosely Senior Member

    Yes, there are a number of Eucalyptus species that wouldn't be appropriate for boat building for one reason or another. Most are too heavy and or are difficult to dry, have grain flow issues or something that prevents them from being suitable for boat building.

    Eucalyptus deglupta is grown in many tropical country's for wood production.

    Eucalyptus deglupta is used extensively for boat building, furniture, construction & pulp.

    I think it's probably one of if not the only Eucalyptus species that is.

    Almost didn't figure out it was a suitable tree species because everything I read about Eucalyptus said how unsuitable it was. Spent quite a bit of time researching tree species on Big Island that would be suitable.

    It saws & finishes well except for quarter sawn doesn't finish as easily or nice from what I understand. So jut keep flat sawn or vertical sawn lumber for boat.

    Albizia Lebbeck is pretty good but is 39-40 lbs cu/ft, but good strength wise.

    I'll be using Rainbow Eucalyptus deglupta for all the beams in my little house. It's mostly beam frame.

    Cheers, Allen
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

    Eucalypts are very variable between species, but there isn't much one or another hasn't been used for, they vary from species that resemble shrubs to towering giants that were the tallest trees ever recorded, ( Mountain Ash (eucalyptus regnans)). I say were, because shamefully the greatest of them were cut down in the triumph of greed over foresight. Great forests of Mountain Ash still exist, notably in Tasmania.
     
  9. abosely
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    abosely Senior Member

    I was really surprised at how big & tall Eucalyptus deglupta can get. They can get 6' diameter trunks & 200' tall.

    Interestingly, the ones here don't get as tall as other places. I forgot how tall the usually get here. I think it was less than 150'. I imagine there are some real tall ones here, but I think it was meant common heights.

    The ones here don't seem to get growth stress either. Tho I don't think it's particularly bad elsewhere in this species.

    Pretty neat tree.

    Cheers, Allen
     
  10. SukiSolo
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    SukiSolo Senior Member

    I remember hearing that the main Aussie Eucalypts were fast growing because to survive forest fires, often started from lightning, they needed to be to survive!. Actually I think closer to 300' is/was possible in a suitable environment, and the right Eucalypt.

    Mr E is dead right, you are better to seed from the 'giants' and let them carry on growing. Note how the Indian tea plantations grow Rosewood on a 40 year cycle, a big timber for pianos and guitars, and useful cash as well as maintaining the species.
     

  11. Jamie Kennedy
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    Jamie Kennedy Senior Member

    I am going up to a local small lumber yard this morning to get some wood for the Yngling. He specializes in local Eastern White Cedar and some Tamarack, and of course can also get plenty of spruce pine fir but its hard to compete with Home Depot on that stuff. I want to go up and get some pieces and see what I can use them for on this and other projects. It's a small operation he runs from his house so I can really take some time to pick through the lumber, and his brain. Should be fun. I would like to stay away from plywood and glass as much as possible to try and do things more locally and sustainably. Not sure yet on best way to do that.

    First project is just some seats. Existing ones are 37" x 7" x 3/4" teak, cracked a bit but still functional from 1981. He has some tamarack 2x4s and says they really tend to corkscrew as they dry, but what he has should be dried out. I can thinking to laminate them together on edge like a cutting board, using 4 pieces for each floorboard. I am also going to try a couple of one piece seats out of the cedar, but going thicker to 1" or even 1 1/4" in order to be tough enough. Not sure how to seal them yet. I think I will try different methods. Also pick his brain. The seats are removeable and interchangeable so I can try out some different ideas and use it as a test. Long term I need to replace a couple of plywood watertight bulkheads, add an additional bulkhead by the entrance to the cuddy, and replace the removeable seats with a removeable raised floor watertight double bottom. I want to do as much as I can with wood from this guy and see what I can learn in the process. Also looking to make a storage shed, some storage racks, a workshed, and some other projects. Should be fun.

    Good luck with all that local wood in Hawaii. It is good to keep all these different species and varieties going if it helps to do things locally and sustainably. It's kind of like elephant meat. What is the best way to protect a species? Somewhere I think between over-harvesting and over-protection. I think its an old idea, something the various first nations people of the world used to call 'living'. Presumably it worked for thousands of years, more or less. ;-)
     
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