Rebuilding cored deck, trial n errorr, learning by doing and a game of will it float

Discussion in 'Boatbuilding' started by Norado, Oct 15, 2016.

  1. Norado
    Joined: May 2016
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    Location: Le Havre

    Norado Junior Member

    It's been half a year since I removed the first teak plank from my 34 foot sailboat. All the teak was swiftly pulled off and I went on to cutting open the outer skin to assess the extent of balsa rot. I had absolutely no idea how I was supposed to rebuild the deck. Insted of getting my ducks in a row I impulsively went forward on momentum and gutted half my deck in a Top Gearesque "how hard can it be" fashion.

    As I retrospectively started researching balsa core repairs I realized I had dug myself a huge time pit if not also a money pit. I learned about 12:1 bevels and that I had made cuts in the wrong places, that proper core bonding is virtually impossible for the DIYer, delamination will occur, the epoxy will not allow the deck to flex, polyester will not bond and so on and so forth.

    As far as I've learned you can set out to do boat repairs the correct way as described in books and according to best practices and consensus on sites like But being my first project it's hard to relate when you haven't actually done it before. So I've opted for the other way, reading, interpreting, altering and adapting the information to fit my specific problems, trying, failing and praying that it simply will be good enough. The good old good enogh.

    I would be exaggerating if I said the job is almost done, but I am slowly getting nearer a recored and relaminated deck and I guess I'm looking for the universe to tell me that my vessel will not fall apart. I mean, there's probably some voids under my Airex foam core (which is set in epoxy w colloidal silica). The resin to glass ratio is surely off for some of the laminate (too dry before I got the right technique). I've used epoxy so I would think that it should hold up better than if I had chosen polyester.

    How sensitive to mistakes is this fiberglass stuff? Is it really rocket science? I mean the more research you do, the more mistakes you realised you've done. I wonder if boatbuilding would be easier without the internet offering this abundance of information and in some cases disinformation. The simplest of questions can send you straight down the rabbithole and you wake up at night pondering resin to glass ratios.

    I wish I had a smaller project to make all the mistakes before going head first into a 500-1000 hour project. It would be more gratifying knowing that I'm on the right track to a sound vessel instead of questioning whether I'm just creating more work and preparing a repair for a repair. I'm doing this job myself and I'm sure there are numerous boat builders winging it like I've done that can relate to these sentiments, at least when you started out.

    I might come off as incompetent, which I suppose is a fair assessment, but I do my best and I'm learning. You can read until the cows come home, but as far as I'm concerned getting your hands dirty and making your own experiences is the key.
  2. Petros
    Joined: Oct 2007
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    Location: Arlington, WA-USA

    Petros Senior Member

    sounds about normal. do not worry, you are in good company. Even the best and most experienced ship rights can tell you (if they will admit it) of the really stupid mistakes they have made along the way. Sometimes even when you know better, you take short cuts thinking it will save time, only to find out a year or two later (when you have to redo it all) there was a reason for each step in the process.

    I just consider it "stupid tax", part of the process of learning, that can not be avoided (like the other type of tax, and death). It is the hazard of the learning process. Do not bail out, just keep at it and by the time you are done you will be an expert too. Or, vow to never DIY again! either way, it should not happen again.

    Good luck.
  3. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    I did a repair of this type on a rather large yacht. The area was limited to the bow. We cut into the deck from the bottom leaving the fiberglass and outer deck intact. We then rebuilt the decking underneath with epoxy jelly, Fiberglass layers, and cedar tongue and groove. This was not a typical repair for many reasons, but it worked well there. Took 2 people 3 weeks, we spent one week removing rotten wood with everything from a chain saw to a hand grinder with saw blades. The epoxy jelly made it possible because we laid cloth on the ceiling, until it was stiff enough. Cedar added final strength and finished the interior. It was also lighter, impervious to termites and most rot.
  4. leaky
    Joined: Sep 2008
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    Location: nh

    leaky Senior Member

    This is kinda an old post but based on what you are saying it sounds like you've made the project extremely complicated in your mind, if you are just talking about the topside deck. 2 part epoxy bonds really well to practically anything that is a bondable surface, the only thing it lacks as far as bonding goes is a solvent, so certain materials that "want" the solvent to dissolve them like the binder in chopped strand mat, do not work as well. Outside of that it's very user friendly - odds are good if it cured and you didn't do anything to keep it from bonding like adding wax, it's bonded.

    I'd have to see more what you mean by "epoxy will not allow the deck to flex" but in reality epoxy flexes more - my experience is if I build the same structure with polyester and epoxy, the epoxy is a stronger structure but that may not be immediately apparent because the resin itself is more flexible. I've never seen anyone build a hull out of 2 part epoxy but I bet the difference in panel deflection would be quite apparent if it had long flat sections not otherwise supported by structure.


  5. Norado
    Joined: May 2016
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    Location: Le Havre

    Norado Junior Member

    Thank you,

    I'm thinking it will hold up too, it at least seems solid. It's hard when you lack the experience and confidence and there's all these different opinions floating around the interne, gets into your head when you're stuck in a large project like this.t At least I've learned a lot :cool:
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