Preview: How to Build a Caledonia Yawl, Part 6 – Laminating the Stems

15 Responses So Far to “How to Build a Caledonia Yawl, Part 6 – Laminating the Stems”

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  Connor Wallace says:

  Let’s say someone were to laminate the stems in the reverse order, with the outer stem on the inside of the pattern and the inner stem outside of that. Clearly that person would later come to find that when you fit them together in the correct manner that the curves will not line up, except with some serious clamping pressure. Would you advise that person take it as a loss, eat the cost (and material) and start over? Or is this an issue you think can be remedied with a bit of pressure and post production gap filling?

  Asking for a friend…

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    Geoff Kerr says:

    If your friend is listening I suggest a quick trip to the woodstove to destroy the evidence and a fresh start. I can imagine being able to eventually fit the bogus outer stem to the finished hull, but the reshaping it would require would surely be a mess. Fitting the misshapen (is that a word?) inner stem to the molds and keelson would be such a doubt inducing exercise that I would have no confidence in any subsequent steps. Your friend can take comfort in how much easier the second set will be to produce with all of that practice.

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  Geoffrey Adams says:

  Hello Geoff, You certainly do make this look easy and I suppose it’s really not that hard if broken down into small steps as you do. I do have a question though. Lately I have been looking into other sources on laminating and there seems to be a lot of talk about “spring back” of the laminates after the epoxy has cured. I noticed that you didn’t mention anything about springback. Is there something in you method that helps/ eliminates it? Please address this as I am preparing to laminate stems for my Tirrik.

  Thanks,

  Geoff Adams

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    Geoff Kerr says:

    Springback is a real thing. My impression is that it varies with material, thickness, number of layers, the phase of the moon, etc. These Caledonia stems might spring 1/4″ over their whole length (when released from the form, if one end is held in place the other springs away 1/4 or so). That seems pretty negligible to me, and well within my tolerances. Given the potential variables of the accuracy of your form, your beveling artistry, getting the things accurately mounted, etc., I say it is time to carry on and build the boat, As long as you keep things fair from here on out no one, even you is ever going to know if the stem is perfectly shaped or not.

    • 

      Geoffrey Adams says:

      Thanks, Advice heard and preparing to be taken. Here we go!!

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  Derrick Burry says:

  Geoff,

  It appears you have added a bit of tint and thickening agent to the resin. Is this the case?

  Thanks,

  …and I have really enjoyed viewing all your videos!

  Derrick

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    Geoff Kerr says:

    There is definitely thickener in this application. Epoxy is never used for adhesive purposes without an appropriate thickener. May I suggest you review the introductory epoxy tutorial we did in the opening of the series…
    There was no tint added. It is possible to tint epoxy,say perhaps in a sealer coat to match a planned paint scheme, but that would be pointless in this application.

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      Derrick Burry says:

      Thanks Geoff,

      Having watched all your videos quite some time ago, it is difficult to remember which segments covered the fine details. I am planning to laminate some teak much the same way as you did for the stems of the CY. I think a bit of thickener will help in that application too.

      Thanks

      Derrick

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  Robie Gardner says:

  I have a question reguarding the species of wood for laminating the stems. I have a source of douglas fir here in my home town, but the stock has a moderate amount of knots and the growth rings show it isn’t old growth. I’m a decoy carver and I have a large amount of eastern white cedar that is clear of any knots. I know the cedar is a prefered lumber for planking, but is it too soft for the inner and outer stems and floor timbers? What would be a better choice, nor neither? Thank you.
  Robie Gardner
  Portsmouth, VA

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    Geoff Kerr says:

    I would steer clear of cedar, just on the classic assumption that there are stronger woods for structural components. I would suggest mahogany or Doulas fir are the woods commonly used for laminations, and the only ones I have experience with. Any decent lumber yard or mill should be able to get you CVG (clear,vertical grain) DF 2x pieces, usually in no more than a couple of days wait as they get it from their distributor. My very ordinary local yard produced one for me in one day this week. Cedar is fabulous planking, and I have recently used it for seats and floorboards on a designers specification.

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      Robie Gardner says:

      Thank you.

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  Robert Mckeown says:

  Did you make the laminating strips yourself (e.g. by ripping larger boards) ?

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    Geoff Kerr says:

    Yes. This is a table saw exercise. They can be gotten out of a variety of stock, be it 2x6s or some roughcut 8/4. It is certainly possible to find a commercial woodshop or sawmilll to mill them for you. Just work up a cut list and be willing to pay for their labor and overhead. Don’t scrimp on length or width. A little extra will be a big comfort.

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  randall spurr says:

  Great work Geoff, you make it look so easy!

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  edward demarco says:

  Excellent..! cant wait for Part 7