A new wooden yacht build, strip planking technique technique impresses

Discussion in 'Sailboats' started by rwatson, May 15, 2023.

  1. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    Those who can't work to close fits are stuck with using epoxy.Which is a long way from cheap and quite possibly less durable than phenol-formaldehye.A former associate who made propellors for his light aircraft using Aerodux was horrified at the thought using it with high clamping pressure.The last hull I saw made with it has been in regular use for over forty years and it was only stapled together using veneer strips to distribute the load.
     
  2. Rumars
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    Rumars Senior Member

    Have you actually priced phenol-formaldehyde glues lately? Plenty of cheaper epoxies around and you don't have to plan your work around the glues expiration date, or worry if your supplier stored it properly.
    I don't know what your associate uses, but Aerodux 185, requires 0.8-1.2N/mm2 for structural hardwood laminations, and other formulations are similar. 1N/mm2 is 145 psi, that's 10 times atmospheric pressure. Yes it will work with less pressure, but it won't achieve the properties it's famous for.

    Fact is, for the average user, amateur or pro, epoxy is the better overall fit, and that's why it's so predominant. There are niche applications for wich other glues are better, that's indisputable.
     
  3. rwatson
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    rwatson Senior Member

    "Acorn to Arabella" had a serious problem with old Resorcinol glue.

     
  4. rangebowdrie
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    rangebowdrie Senior Member

    I've followed along on the "Acorn to Arabella" series and have contacted them a few times.
    Yes, they are Luddites in many ways.
    Insisting on full length planks with resorcinol glued scarf joints in oak was (IMHO,) not such a great idea.
    Anyway, as noted above, the pressure required for resorcinol is quite high, joints must basically light-tight.
    It has a good reputation for spruce spars where massive pressure can be applied to relatively small areas and the wood is soft. We think of teak as a "hardwood", but it really is a "soft" hardwood.
    For the less-than-perfect among us epoxy makes a lot of sense.
    Many of the failures of epoxy joints can be attributed to making the joints TOO tight.
    Epoxy wants some room, it's a physical bond, not a chemical bond, and it needs some room for its "physical" presence in the joint.
     

  5. Howlandwoodworks
    Joined: Sep 2018
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    Location: USA MO

    Howlandwoodworks Member

    You must have all of your ducks in a row if you are going to used formaldehyde glues.
    It is perishable 12 month shelf life, must be stored at room temperature and accurate mixing proportions are paramount. The viscosity of formaldehyde glues and the resulting glue mix is predominantly dependent upon temperature and can be cured at elevated or room temperature, or by (RF) radio frequency energy to accelerate drying time. I used it mostly for vacuum bagging wood veneers. You can get it with an anti creeping additive so it won't slide around when clamping or bagging.
     
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