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Strip Canoe With All Walnut?

Discussion in 'Strippers, Stitch-n-Glue, and Other Wood Composite' started by RoadRunner, Dec 19, 2015.

  1. RoadRunner

    RoadRunner Enthusiastic about Wooden Canoes

    Howdy All -

    I recently came into a huge amount of walnut that is about 3/4" x 2-3" x 6-8 feet. It's in good shape, dry, about 15 years old, no rot, and it's been nicely weathered under the cover of a deck. With the help of a planer, a table saw, and a router table w/ the right bits, I'm pretty confident that I could make more than enough strips for an entire canoe. My question is to the experienced builders out there: is stripping an entire canoe in walnut like this a realistic option? Any drawbacks?
     
  2. Andre Cloutier

    Andre Cloutier Firestarter. Wicked Firestarter.

    If you're building a stripper with glass inside and out, core material is pretty much at your discretion. Are there better suited woods? Sure, but if they can build one out of chopsticks walnut would work, but yours will be heavier.
     
  3. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Other than the obvious weight increase (which when compared to other materials that canoes get made from shouldn't be all that bad) I might anticipate the possibility that it might be a bit more brittle if your design calls for a lot of twist when applying strips. I'd probably also do a small test panel first, using the same glass and resin that you intend to use on the real boat. Walnut is pretty dense and you may not get quite as good of a bond. Let it harden for about a week, then bend it a bit and hit it a few times with a mallet to see if it delaminates. In reality, resins don't penetrate anywhere near as far as a lot of people think they do, but wood hardness can make somewhat of a difference in bond strength. I saw a stripper once that was all genuine mahogany - no stripes, just nice wood, and it was gorgeous.
     
  4. OP
    OP
    RoadRunner

    RoadRunner Enthusiastic about Wooden Canoes

    Good points, all.

    Todd, you reference the wood being brittle....is that based on my description of it being dry, or is that the nature of walnut? If it's because the wood is dry, can I oil the wood first, or does that cause other issues?

    Thanks again for the insights. Tremendously helpful as always.
     
  5. Jim Dodd

    Jim Dodd LOVES Wooden Canoes

    Walnut has an oil in it that is rumored to cause bonding issues with resin. I've not seen this with epoxy, but as Todd states a test would be prudent.

    I would think that Red wood and Walnut would be similar in brittleness It should be doable.

    As far as weight, you could cut the strips thinner. I know a builder that uses 1/8" WRC for his hulls.

    Jim
     
  6. Fitz

    Fitz Wooden Canoes are in the Blood

    There is superstition along the lines of black walnut causing bad luck when used in boat building. I haven't been able to chase a source down. May be a result of it being used as coffin wood. Your mileage may vary. Sorry to put that bug in your ear...;)
     
    Craig Johnson likes this.
  7. OP
    OP
    RoadRunner

    RoadRunner Enthusiastic about Wooden Canoes

    Bah, it's all rubbish.
     
  8. Andre Cloutier

    Andre Cloutier Firestarter. Wicked Firestarter.

    Fitz, always heard that too. Found this..."Folklore and the Sea" by Horace Beck, which
    describes black walnut as being horribly bad luck to have on or in a
    boat.
     
  9. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Brittleness is just the nature of walnut, combined with it not usually having grain which is as straight as the typical stripper woods. You don't want to oil it, as it would prevent the epoxy from bonding properly when you do the fiberglass work. Clean, dry wood is what you want throughout the stripping process. I have heard of people wiping down woods that tend to be naturally oily with acetone before putting resin on them to theoretically remove excess oil, but have never tried it myself.

    On the other hand, when somebody posts a thread on a boating forum where they're having serious epoxy or wood/epoxy problems and failures, it very often is most likely due to some sort of chemical contamination, due to the use of assorted solvents to "clean" the wood. Dry, freshly sanded wood seldom needs cleaning at all other than dust removal, and it's a good idea to resist the temptation to treat it with anything at all before the epoxy, as it may actually do more harm than good. This is also true farther along in the process where you are dealing with epoxy-to-epoxy bonds. We use water to clean any amine blush from epoxy before bonding, but no other chemicals.

    I've heard the old walnut/bad luck thing before, but unless you're planning on becoming some sort of ancient mariner, I wouldn't worry much about it.........
     
  10. OP
    OP
    RoadRunner

    RoadRunner Enthusiastic about Wooden Canoes

    Man this is great. Thank you so much. I think I'll learn a lot about this by testing sample pieces. What I have is extremely dry and seems really strong. I'll sand and plane as needed before going forward.

    As for the folklore, my plans for the boat are limited towards calm lakes and shallow rivers. Otherwise I might be concerned. Still, appreciate the knowledge.
     
  11. Andre Cloutier

    Andre Cloutier Firestarter. Wicked Firestarter.

    FWIW, i've laminated walnut with other hardwoods with epoxy many times, and cant resist testing the offcuts of any woods i do. The walnut
    i've used has been both air and kiln dried and sanded after planing, but never had anything applied to it. Never any concerns about joints, they always shear behind the glue joint as this one has - front piece is maple, walnut in back. You can see where it actually pulled the maple off. And it looks so good with figured maple.....;)
     

    Attached Files:

  12. OP
    OP
    RoadRunner

    RoadRunner Enthusiastic about Wooden Canoes

    Hey Andre -
    Thanks for your post. You're right about walnut and the figured maple. Just stunning.

    Not sure I understand what you mean by "they always shear behind the glue joint...." Can you clarify?
     
  13. Andre Cloutier

    Andre Cloutier Firestarter. Wicked Firestarter.

    Sure,
    when you do destructive testing, the last thing you want to see during a production run is glue not pentrating and producing fibre pulls on shearing the joint. The epoxy is penetrating well into the fibres, and maintaining its bond, causing the fibres to pull away from the block rather than a clean break with a nice shiny glue surface on either or both sides. That is, the wood is yielding and not the glue joint. For your purposes, any easily sanded urethane glue is fine for holding strips, but if i understand correctly your concern is adhesion of the glass to both sides of the hull. I think as a failsafe i would precoat the boat, allow it to soak in until almost green, then apply the glass to make sure it didnt starve and show weave after the fact. Todd will chime in if this is even advisable, but i've had areas in the past that seemed starved and couldnt fill the weave after the fact. I see it on polyester boats often as well, but strippers aint my thing so if Todd and others say to do something during construction, i would.
     
  14. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Some folks like to pre-coat the hull with resin before glassing, others just lay the dry glass cloth on the bare wood and saturate through it in one step. Both techniques work. If you do pre-coat though, wait on applying the fiberglass until the pre-coat has hardened enough that you won't disturb it, and it is neither still sticky or going to come off on the cloth as you unroll and position it. You don't want small spots of nearly hardened resin coming off of the pre-coat and onto the cloth. They can inhibit the proper saturation of the cloth with fresh resin as you do your glassing. Depending on the speed of your hardener, the amount of time it takes your pre-coat to harden enough to start the next step without getting stuck in the pre-coat can be anywhere from a half hour to several hours.

    On baby-butt-smooth new wood (which is pretty much what your prepared stripper hull should look like before glassing) I don't usually pre-coat the wood. I lay dry cloth on dry wood and work the resin into it with a roller and a squeegee made from a 1/2" thick slab of ethafoam packing foam. I either start at one end and work toward the other, or start in the middle and work outward in all directions, using a continuous stream of small batches of freshly mixed resin. One of the best ways to insure success is to have a person you can trust who does nothing but mix those resin batches for you while you apply them. Trying to both apply it and rushing to mix accurate resin/hardener batches yourself as you do is a frequent source of glassing problems on boat forums - and those goofs are really hard to fix.

    Once the cloth is on and all properly saturated with no bubbles or dry spots it should be down tight to the hull (not floating in pools of excess resin) and your surface should have a very uniform cloth texture from your squeegeeing. The next step is to hang around for as long as it takes for this resin to harden. It is possible for the wood to wick resin out of the cloth in places, leaving white-ish dry spots of fiberglass cloth. As your fiberglass layers cure you want to be constantly checking the hull, and if needed, adding a bit more resin to any dry spots that appear. This is your only chance to fix these places without major surgery, so don't just stick the glass on, close the door and walk away. If anything in this case, I would think that since it is more dense than most stripper woods, the walnut might be less prone to wicking resin than cedar, spruce, etc. Once the glass hardens enough that you can work on it without the cloth being disturbed, you're ready to start your filler coats to fill the cloth texture.
     
  15. Jim Dodd

    Jim Dodd LOVES Wooden Canoes

    I agree with Todd.
    Staple holes love to weep epoxy away, as does gaps. If you go staple less, or fill the holes, and have a surface free of gaps and voids. No need to precoat.
    If your stripping technic isn't up to snuff, precoat.

    I love those white foam "Cigar" type rollers, for applying epoxy resin.
    Depending on the pot life of your epoxy, I like the old black foam 1/4" nap paint rollers to suck up excess resin. A lot of people prefer squeegees, I just always ended up with lines in my cloth, using them.

    Great advice so far ! And it's before you build, not after you made the mistakes !

    Jim
     
  16. David Satter

    David Satter LOVES Wooden Canoes

    I did the interior of a large sailboat with black walnut trim years ago. When the travel lift was launching it one strap broke and the sailboat fell to the ground , landed on the keel , but healed over and broke the mast . Was a bad day. Wish someone would have told me.
     

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