Fiberglass Sheathing a 1962 Carvel Hull

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • gypsie
    NSW Australia
    • Jun 2010
    • 8173

    Fiberglass Sheathing a 1962 Carvel Hull

    My boat broke its mooring and was damaged.
    Insurance company wrote it off, (repair costs were higher than agreed value - because of labour), i bought it back and am now in the process of repairing it.
    Thread here; http://forum.woodenboat.com/showthre...ew-Deck/page17 From about page 17 I'm dealing with the current (involuntary) issue. (Page 1 gives you some insight into the boat, age/history).

    Repair includes bringing the boat back to bare wood.
    First she was sand blasted, gently but with predictable (minor) consequences, and now I am in the process of sanding off the remaining paint and making her fair again.

    IMG_6869.jpg

    IMG_6875.jpg



    I want to consider sheathing her in epoxy and fiberglass.

    I have been reluctant to sheath for a number of reasons, examples;
    A) - the hull is sound, the planking and framing are sound, the caulking is sound. She is in general good health. (but she is aging).
    B) - water ingress under the sheathing. How do i deal with areas for example around the ballast - how do i prevent water ingress and the glass working away....?
    C) - Scale - am i just introducing a bloody huge job, with attendant costs, without a good reason.
    D) - Won't the movement of the hull crack the glass and then - water ingress under the sheathing....? Note the hull is sound and there is no discernible movement of the planks (when she's not getting buffeted onto a beach). Caulking is good as of before sand blasting, now some of the compound is flaking out.

    The Pros are fewer BUT persuasive;
    i) simply protecting the boat. I must admit i lay awake nights, from about 9 months plus after haul out, worrying about worms. I've had debris catch my mooring line and knock bottom paint off - so emergency haul out for repairs below the waterline = expensive and time consuming.
    ii) Longevity - I know there is a sentiment expressed in post #5 here; https://forums.ybw.com/index.php?thr...eathing.79345/, but - with a sound boat, given what we know about modern materials - this could be a reliable way of protecting this boat indefinitely. Given the positive condition of the boat - encapsulating it now could be a genuinely good thing.


    Questions to start off with;
    -Process for reliably sheathing the hull.
    -Thickness of cloth, type, number of layers.
    -Do i need to drop the ballast off? Do i glass over it too?
    -Do i need to glass the inside as well ? (Who was that french dude?)
    It's all fun and games until Darth Vader comes.
  • wizbang 13
    Senior Member
    • Oct 2009
    • 24796

    #2
    Re: Fiberglass Sheathing a 1962 Carvel Hull

    Sheathing a carvel boat is like varnishing a cabin side... in that 90 percent of the work is in the prep.
    To sheath sucessfully, the boat must be dried out..that is a year under a roof.
    The hull must be stabilized and locked up....that means ripping out the existing seam compound and cotton and either gluing in splines or solid epoxy.The wide planks may want to be "kerfed" with a skilsaw blade...this is an easy enough job, but one must realize there is no going back.
    A boat gets to a certain age.. there are hard questions to ask...easy to answer.

    Comment

    • pcford
      boatwright/film/video
      • Jul 2002
      • 9875

      #3
      Re: Fiberglass Sheathing a 1962 Carvel Hull

      Just don't do it. If the boat is on its last legs and you do not have the resources to do it, you could get a few more years out of it. After that, mulch.

      Comment

      • gypsie
        NSW Australia
        • Jun 2010
        • 8173

        #4
        Re: Fiberglass Sheathing a 1962 Carvel Hull

        Originally posted by pcford
        Just don't do it. If the boat is on its last legs and you do not have the resources to do it, you could get a few more years out of it. After that, mulch.
        She is a long way from mulch. Definitely not on her last legs - far from it.
        It's all fun and games until Darth Vader comes.

        Comment

        • gypsie
          NSW Australia
          • Jun 2010
          • 8173

          #5
          Re: Fiberglass Sheathing a 1962 Carvel Hull

          Originally posted by wizbang 13
          Sheathing a carvel boat is like varnishing a cabin side... in that 90 percent of the work is in the prep.
          To sheath sucessfully, the boat must be dried out..that is a year under a roof.
          The hull must be stabilized and locked up....that means ripping out the existing seam compound and cotton and either gluing in splines or solid epoxy.The wide planks may want to be "kerfed" with a skilsaw blade...this is an easy enough job, but one must realize there is no going back.
          A boat gets to a certain age.. there are hard questions to ask...easy to answer.
          So far, so 'not going there'.
          Stabilised is not just about wood shrinking/expanding - its about movement at the seams..? Prevent cracking of the glass at the plank joins. Splines I presume, to be glued in - effectively turning the hull into a strip built hull with edge glued planks.
          What you're describing to me is a radical change in the nature of the boat.

          Ripping out seam compound and caulking cotton, could be; run the circular saw (kerf) along seam - set to a depth that doesn't cut the frame in two. With a 3mm thick blade, insert a 3mm spline....... That is not as much work as it feels at first blush. A baton screwed on to guide the saw.......
          Would the spline have to go all the way through - or - with a 28mm plank, insert a 20mm deep spline? Or maybe just a 10mm spline all round.
          It's all fun and games until Darth Vader comes.

          Comment

          • pcford
            boatwright/film/video
            • Jul 2002
            • 9875

            #6
            Re: Fiberglass Sheathing a 1962 Carvel Hull

            Originally posted by gypsie
            She is a long way from mulch. Definitely not on her last legs - far from it.
            Then don't do something that will likely be very bad for the boat.

            Comment

            • gypsie
              NSW Australia
              • Jun 2010
              • 8173

              #7
              Re: Fiberglass Sheathing a 1962 Carvel Hull

              West system have a publication on Wooden boat restoration and repair. Section 5.1.1 page 28 concurs with Whizbang.
              WEST SYSTEM® technical publications and DVDs provide detailed procedures and instructions for specific repair and construction applications. Find your closest WEST SYSTEM dealer. Contact Us


              Indeed - no going back.
              It's all fun and games until Darth Vader comes.

              Comment

              • RFNK
                Port Stephens, Australia
                • Feb 2007
                • 26941

                #8
                Re: Fiberglass Sheathing a 1962 Carvel Hull

                Wizbang is right, except it won't need a year to dry out. The hull must be stabilised prior to sheathing. The best way to do that is by splining. This involves having a splining blade made up for a small circular saw then running it along each seam on a batten. A spline is then glued into each seam. This is not a big job and I can help with locating a shop to make the blade.

                Then you have two choices. Cold moulding or structural sheathing. Double diagonal strips of timber, sheathed, or two layers of glass. My first thought would be a moderate grade of double bias but another form of glass might be better - that's easily checked. All epoxy, of course. Seabirds are true classics. Do this properly and you'll have a great boat. I I were you, I'd use multiple layers of glass (probably 2) over a spline hull. I think this is the simplest method that will actually work. Of course the hull must be free of any rot and dry enough. Once the westerlies kick in, in another month or two, it'll be dry enough.
                Rick

                Lean and nosey like a ferret

                Comment

                • RFNK
                  Port Stephens, Australia
                  • Feb 2007
                  • 26941

                  #9
                  Re: Fiberglass Sheathing a 1962 Carvel Hull

                  The splining blade cuts through the seam but not into frames. To be most effective it should be a tapered blade. I tried years ago to buy one but couldn't find one. But any good saw shop can make one up. A good investment and should be easy to sell. The spline can be glued in with either epoxy or polyurethane. Poly likes moisture, epoxy doesn't.
                  Rick

                  Lean and nosey like a ferret

                  Comment

                  • Peerie Maa
                    Old Grey Inquisitive One
                    • Oct 2008
                    • 62422

                    #10
                    Re: Fiberglass Sheathing a 1962 Carvel Hull

                    If the hull is stabilised so that there is no movement in the wood at all anywhere, what does sheathing it add? You have a strong sound boat before you apply any e/glass, so why do you need to do it?
                    It really is quite difficult to build an ugly wooden boat.

                    The power of the web: Anyone can post anything on the web
                    The weakness of the web: Anyone can post anything on the web.

                    Comment

                    • RFNK
                      Port Stephens, Australia
                      • Feb 2007
                      • 26941

                      #11
                      Re: Fiberglass Sheathing a 1962 Carvel Hull

                      If you decide to go this way, get a basic moisture meter. They are cheap and you'll be able to check the dryness of your planking over the next few weeks etc.
                      Rick

                      Lean and nosey like a ferret

                      Comment

                      • RFNK
                        Port Stephens, Australia
                        • Feb 2007
                        • 26941

                        #12
                        Re: Fiberglass Sheathing a 1962 Carvel Hull

                        Originally posted by Peerie Maa
                        If the hull is stabilised so that there is no movement in the wood at all anywhere, what does sheathing it add? You have a strong sound boat before you apply any e/glass, so why do you need to do it?
                        The fasteners are old and would be allowing moisture through. The old planking is softer and weaker. With structural sheathing, the hull will be stronger, more waterproof, antifoul will last much longer and the interior of the boat will be drier.
                        Last edited by RFNK; 06-09-2020, 04:15 AM.
                        Rick

                        Lean and nosey like a ferret

                        Comment

                        • RFNK
                          Port Stephens, Australia
                          • Feb 2007
                          • 26941

                          #13
                          Re: Fiberglass Sheathing a 1962 Carvel Hull

                          For the record, my boat, Masina, is strip planked, edge nailed and glued, and sheathed. Built in 1975, sailed all around the world, and the hull remains virtually as new. Hull maintenance is negligible.
                          Rick

                          Lean and nosey like a ferret

                          Comment

                          • Phil Y
                            Banned
                            • Apr 2010
                            • 21066

                            #14
                            Mine likewise, but built in 1974 and only sailed Australian waters. My leaky deck, now replaced, has over the last few years let water into the hull and I suspect that to be the cause of some topside seams cracking as she dries out in the summers. Time will tell.

                            Sent from my CPH1851 using Tapatalk

                            Comment

                            • RFNK
                              Port Stephens, Australia
                              • Feb 2007
                              • 26941

                              #15
                              Re: Fiberglass Sheathing a 1962 Carvel Hull

                              Well, happily Masina's plywood deck was also sheathed properly in 1975 and remains perfect.
                              Rick

                              Lean and nosey like a ferret

                              Comment

                              Working...