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Scarfing rail stock

Discussion in 'Traditional All-Wood Construction' started by DAVID EDGERLY, Jan 6, 2014.

  1. DAVID EDGERLY

    DAVID EDGERLY Enthusiastic about Wooden Canoes

    I have typically used epoxy for all scarf joints,I am considering using titebond 3 for rail stock scarf realizing that this type of joint does not have any gap to fill I thought this white glue might be better. any body have any experience with this.
    Dave Edgerly
     
  2. Fitz

    Fitz Wooden Canoes are in the Blood

    I saw a comparison of glues once somewhere - maybe WoodenBoat- not sure. But if memory serves correctly, titebond compared the same or even did better in the comparison parameters than epoxy. I remember being surprised. You might find it with a Google search.
     
  3. Larry Meyer

    Larry Meyer Wooden Canoes are in the Blood

    I have used T2 on a variety of applications, canoes and outdoors stuff, and I am a big fan of it. It’s so much easier to use than epoxy and the tack is superfast and convenient. I argue all the time with epoxy devotees about t2.
    I do know that a guy I know who both builds guitars and repairs wooden boats has no qualms whatsoever about using T2 on boats, in place of epoxy .
     
  4. Larry Meyer

    Larry Meyer Wooden Canoes are in the Blood

    I have scarfed new inwale ends with T2. To get a wide enough deck, I widened a piece of walnut by butt jointing two pieces on the outside edges. No biscuits or anything. Just butt glued them all together with T2.
     
  5. Dave Wermuth

    Dave Wermuth Who hid my paddle?

    I used Titebond 3 on a split bamboo fly rod that had delaminated because some unfortunate angler put the rod away wet. All six strips had to be reglued in several places. All I can say is that the T3 is still holding the rod together. I am really impressed given the stress and flex that takes place in a 6wt fly rod. you mileage may differ, but I'm a believer.
     
  6. OP
    OP
    DAVID EDGERLY

    DAVID EDGERLY Enthusiastic about Wooden Canoes

    Thanks for all input I will be using more T2 in the future knowing that others have been doing this with success. I have been scarfing planking for length on this lapstrake project using epoxy may try T2 if I build another one. It would make cleanup easier.
    Dave Edgerly
     
  7. Jan Bloom

    Jan Bloom LOVES Wooden Canoes

    Use T3 for scarfing the rails and ribs. Much better then T2 when it comes to water.
     
  8. Dave Osborn

    Dave Osborn LIFE MEMBER

    I use G-Flex epoxy for scarfing gunwales.

    I think T3 is waterproof, although I had a bad experience with it on a porch repair that was exposed to the elements... maybe it was the treated wood...??
     
  9. Lazy Jack

    Lazy Jack LOVES Wooden Canoes

    I scarfed my OT outwhales with T3. No problems.
    I laminated a set of ribs for an adirondack guide boat using T2. No sign of delamination after several years.

    I laminated a set of adirondack guide boat ribs using T3. They started to fall apart as soon as I released the clamps and I had to throw them all away.

    Yes the wood was dry,
    yes I did apply a heavy coat to both surfaces,
    yes the temperature was around 70,
    yes the glue was cured,
    yes it was a new bottle of glue,
    yes there was glue on BOTH of the separated surfaces making this a glue failure not a wood failure,
    yes I am glad I discovered it before I started to build a boat around them!

    No, I really don't trust T3 anymore. I'll use epoxy from now on...
     
  10. Chuck Hoffhine

    Chuck Hoffhine Wooden Canoe Nut

    Tightbond III

    I have an engineer friend at Franklin International, the makers of Titebond glues. I asked him his opinion of using Tightbond III on canoes and below is his response. I have not included his name or number but would be happy to pass it on to interested people through a PM. He does speak of epoxy covered canoes which usually isn't 'what we do' but his information I think is helpful.

    -Chuck


    Dear Chuck,

    I do not recall that specific exchange, but this topic comes up regularly. I am quoted on a regular basis because part of my work is on the public end of this company, and you are more than welcome to do so. My only request is that my statement remains intact to avoid any confusion out of context.

    Titebond III is not recommended for applications where continuous submersion is entailed, not because it will fail but because it raises the question of liability. Since wooden canoes are normally finished with CPES and/or several layers of epoxy, virtually every type of wood glue has been used successfully. This includes the most basic white glues, which offer no water resistance, and they hold together because as long as the epoxy remains intact it will not be exposed to water. It has been argued that even if damage does occur, it is unlikely to result in catastrophic failure because the process of dissolving the glue takes time. Canoes tend to spend more time out of the water than in it, so scratches are typically repaired before any damage can propagate through the glueline. Cross-linking or catalyzed PVAs such as Titebond II or Titebond III feature high levels of water resistance, although when completely saturated with water they will lose strength until they are again fully dried. Our specific recommendation is to use marine grade epoxy or other resin based adhesives for this purpose. We are fully aware that Titebond II and Titebond III are both commonly used in this application, but that this is a calculated risk on the part of the end user.

    This likely brings up another common question: What is the difference between Titebond II and III? Products are often designed to pass specific tests, and such is the case for both of these products. Titebond II exceeds the requirements of ANSI/HPVA Type II water resistance, which Titebond III exceeds the requirements of ANSI/HPVA Type I water resistance. Both of these tests are conducted using 6” x 6” birch laminates glued together to make three-ply plywood.

    Type I testing involves cutting the 6" by 6" assemblies into 1" by 3" specimens, boiling them for 4 hours, then baking the specimens in an oven at 145°F for 20 hours. Next, they are boiled for an additional 4 hours and immediately cooled using running water. The specimens are sheared while wet, and the bonds must pass certain strength and wood failure requirements to pass the Type I specification.

    Type II testing involves cutting the 6" by 6" assemblies into 2" by 5" specimens, soaking them for 4 hours, and then baking the specimens at 120°F for 19 hours. This is repeated for a total of three cycles, and the bonds must not delaminate in order to pass the Type II specification.

    Rather than simply being a better or worse product, Titebond III is different from Titebond II. While Titebond III is capable of withstanding boiling water, it has greater thermal plasticity in lower temperature ranges. For instance: we test our wood glues for shear strength using hard maple at both room temperature and 150°F. At room temperature, both products are stronger than wood and therefore indicate the shear strength of maple, which averages between 3200-3400 PSI. At 150°F Titebond II loses roughly half of its’ bond strength and Titebond III loses nearly 2/3rds. Since creep correlates directly with thermal plasticity, it is evident that Titebond II has greater resistance to mechanical creep than Titebond III.

    Please feel free to contact me
     

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