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Wood for guide boat ribs

Discussion in 'Adirondack Guideboats' started by Gary Jacuk, Feb 6, 2019.

  1. Gary Jacuk

    Gary Jacuk New Member

    So I'm the new guy starting my first guide boat and am looking for opinions (I know everybody's got one) on alternate wood for laminated ribs. Spruce (sitka) is rare and very expensive, like $10.00bf here on the west coast and most, if not all, construction lumber is doug fir. I'm wondering if anyone has used alternative woods for making ribs? What has worked for you? It would be a shame to put all the effort into making ribs and find they are inferior, so I'm looking for a bit of help and advice.
    I found a site called Workshop Companion (sorry I can't post a link) with a chart comparing various woods and one wood which compared very favorably to spruce was poplar !! Anybody have any thoughts?
    Thanks.
     
  2. OP
    OP
    Gary Jacuk

    Gary Jacuk New Member

    So here's the info I found on the two woods, sitka and poplar, and according to these numbers, the two are almost identical in properties. Significantly different in price and availability.

    Wood Specific Gravity Compression strength Bending strength Stiffness Hardness

    Sitka

    Spruce 0.40 5.61 10,200 1.57 510


    Poplar 0.42 5.54 10100 1.58 540

    I made a sample rib of poplar and am sending it off to someone who can compare it to a spruce rib and see how it stacks up. It's a number 8 rib for a 16 foot boat and weighed in at an amazing 2.25 ounces. Very stiff, but the laminating and epoxy probably contribute significantly to that. Still seems very fragile to someone not familiar with such things
    My opinion is that the only drawback is tradition......"They've always had spruce ribs". Much like acoustic guitars have almost always have spruce tops. So the saga continues.
     
  3. MGC

    MGC Paddlephile

    Gary,
    Your post dwelled without any responses...that's unfortunate. The obvious question that was never asked is what are you building? A guideboat built in the traditional way is constructed with spruce knees.... the spruce is selected from root/tree base stock and then sawn to shape.
    If you are building a modern version of a guide boat laminating it to fabricate the ribs the wood selection seems less relevant in which case popler is probably fine..
     
  4. OP
    OP
    Gary Jacuk

    Gary Jacuk New Member

    MGC,
    I'm going to build a modern version of a guide boat and was looking for feedback on alternative materials like poplar. I made a poplar laminated rib and it compares very favorably with spruce, so I will go ahead with using that. You are correct in that with laminated ribs the ribs they are probably as strong as spruce ribs cut from stumps, perhaps stronger. So then it becomes a matter of tradition in using the original materials.
    I live in an area where cedar is plentiful and have managed to hook up with a fellow who has a sawmill, some nice, dry cedar logs and is willing to work with me on cutting lumber for making strips. Should be interesting.
    Going to turn this into a build thread and document things along the way. Hope you all find it of interest.
     
  5. OP
    OP
    Gary Jacuk

    Gary Jacuk New Member

    So progress is being made on the boat. Using John Michne's book (which is available on Amazon) I was able to use the CAD drawings and have a full size set of plans for the ribs and stems printed. Then off to the bandsaw and oscillating spindle sander to cut out patterns and make up forms for laminating the ribs.....lots of patterns and forms and lots of dust! I also got some flatsawn 8/4 poplar and back to the bandsaw and drum sander to make 2" x 1/8" x 32" strips for laminating. Cutting the poplar from the edge gives me quarter sawn strips which bend more easily and uniformaly as I learned in a recent adventure into luthiery. I was able to use a hot pipe that was used to bend guitar sides to heat the strips and form them to the bending forms, relieving at least some of the stress on the glue joints. Pretty easy to do once you get a feel for the wood releasing. And no sawdust !!! Soon some actual rib blanks.

    A little background. I'm what you would call in the skiing world terms an "advanced intermediate" when it comes to woodworking. Got a nice, if messy, shop and some decent tools accumulated over the last 40 years. My interest in guideboats comes from the fact I grew up in upstate New York and was reminded of these wonderful boats on a visit to the Adirondack Museum a few years back. Now retired in the foothills of the Sierra Nevada mountains in California with time and a strong interest to be creative and challenged by a project...I think this is a good choice.
    As soon as I'm off probation I'll post some pictures of the progress.
     

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