Seam repair

Discussion in 'Boat Design' started by jscrae, Sep 21, 2008.

  1. jscrae
    Joined: Sep 2008
    Posts: 1
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    Location: Duluth

    jscrae New Member

    This is my first post ever. We are restoring a 32' 1961 Chris Craft Constellation. The previous owner routed the seams to about a 1/4 inch, some are wider though, and filled them with an aggressive, rigid caulk. We have removed the caulk, replanked where needed, including replacing a couple of frames. We've sanded, faired, and filled screwholes, painted the hull with primer because we live in MN where the winter comes early. Now we need to figure out what to do with the seams. We're leaning toward this option-- epoxy in wood strips to the areas where the seams are wider than 1/4 inch and then rout everything evenly and fill with BoatLife polysulfide caulk. We know this will leave us with much wider seams than the original design... Any ideas about this? Will we have too much movement in the boat with such wide seams?
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Is this a carvel, batten seam or double planked boat? The construction type would lend a lot toward the repair options.

    Typically once you destroy seams, you have to replace them. Double planked boats are more tolerant of "repaired" seams then the other types.

    You're going to have considerable movement in carvel and batten seam construction, meaning the seams need to be strong, tight and of course water tight. Double planked will have less movement, but there will still be some. Likely more then epoxy can tolerate, unless then planks are removed, cleaned and bedded in thickened epoxy, at which point your seams could be wide open, tight or anything in between.

    If memory serves me, these were battened boats with a 'glass superstructure. The battens carry the seam loads, but the fasteners and plank edge keep the movement down. If the plank edges have huge gaps, even with goo in a tube squeezed in, they'll move a lot, tearing out the fasteners pretty quickly, which is probably what is causing your leaks (assumed).

    If a battened boat is leaking, then the fasteners are spent and need to be replaced. Addressing the seam gaps isn't going to solve much.

    My recommendation is to systematically remove each plank, clean it's seam edges and refasten, tight against it's neighbor, then move on to the next plank. At some point during this process, you'll notice the planks are landing a fair distance off where they used to live. You can install filler or stealer pieces to accommodate this, which will bring you back to where the planks want to live.

    Planking is a consumable item (just like an air or oil filter on a car), intended to be replaced after a specific amount of service. You can try to "nurse" this worn out material along, live with the leaks or replace the planking and it's fasteners.
     
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