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David Ryan

David Ryan is a boat builder and USCG licensed master captain. He is the owner of Sailing Montauk and skipper of Montauk''s charter sailing catamaran MON TIKI You can follow him on Twitter @CaptDavidRyan

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  1. Avatar James B Franks
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    says:

    What additional information or tests did the USCG want to approve the plywood?Report

    • Avatar David Ryan in reply to James B Franks
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      says:

      We had to send a sample of our plywood to an ASTM certified lab and have a battery of tests conducted on it. It came back about 65% stronger than required to meet the USCG spec, and the USCG spec itself includes a generous safety margin. MON TIKI is going to be one very strong boat!Report

      • Avatar BlaiseP in reply to David Ryan
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        says:

        If you’re the very first builder to get through this certification process, you should submit your story somewhere others could benefit from it.Report

        • Avatar David Ryan in reply to BlaiseP
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          says:

          Yes, we should and we are. You guys are my beta readers.  😉Report

          • Avatar BlaiseP in reply to David Ryan
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            says:

            I’ve been dinking with the design of my houseboat in a desultory way.   Every pontoon houseboat I’ve ever seen has been a marvel of both ugliness and unseaworthiness.   Mine won’t be.

            I’m learning how to do expanding foam wall construction onto a draped form,  making it possible to have an insulated air conditioned space, like a fridge itself.   Thick wall though, unavoidably Roger Dean-ish, there are no corners, it’s all curves and chicken wire on forged steel rods.Report

            • Avatar James Hanley in reply to BlaiseP
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              says:

              I’m learning how to do expanding foam wall construction… there are no corners,

              Perfect for Wisconsin!

              And we’ll finally see that house of foam
              …It’s our dream vacation in the DellsReport

              • Avatar BlaiseP in reply to James Hanley
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                says:

                Won’t be build in Wisconsin.   I’m trying to confine the keels of the standoff pontoon skids to the dimensions of a standard lowboy trailer: that’s my constraining dimension.    Neither love nor money could convince me to spend so much as a cent in the Wisconsin Dells.

                I don’t do dream vacations.   I don’t work more than 10 months a year anyway, screws up my taxes.   I put the sharp point of my compass point down in a port town and swing the pencil point out a day’s voyage out, looking for somewhere to put in of nights.  If I play my cards right, anywhere I can get AT&T to give me a data channel, I’m in business.Report

              • Avatar James Hanley in reply to BlaiseP
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                says:

                I’m trying to confine the keels of the standoff pontoon skids to the dimensions of a standard lowboy trailer:

                Sounds pretty constraining for a house boat.  Love the overall idea, though.Report

              • Avatar BlaiseP in reply to James Hanley
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                says:

                That’s an understatement, heh.   Clearly the boat is going to be wider than the truck bed.   A flat bottomed boat is a lot easier to work with but if I do it right, I can put in some system to adapt it to a standard truck trailer.

                Louisiana waters feature many submerged snags:  if I go the pontoon route, I’m going to fill them with foam and armor the bottom with the aforementioned skids, taking guidance from the little crawfish boats that roar around in swamps, running over submerged logs and such with considerable aplomb.Report

  2. Avatar wardsmith
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    says:

    Are those screw/washer combinations a permanent part of the boat now, or do they unscrew before the fiberglass epoxy stuff goes on?Report

    • Avatar David Ryan in reply to wardsmith
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      says:

      The screws/washers are performing a clamping function, and are removed prior to the exterior being skinned in glass and epoxy. That’s what we did today for the port hull: took out all the screws and started filling and fairing in preparation for glassing.Report

      • Avatar Stillwater in reply to David Ryan
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        says:

        So how did you connect the skin of the hull to the framing? Or is it floating?Report

        • Avatar Stillwater in reply to Stillwater
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          says:

          Ahhh. GLUE! Is that right?Report

        • Avatar David Ryan in reply to Stillwater
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          says:

          Glue is the correct answer.

          The boat has very few fasteners or other metal components. She’s glued together using epoxy and additives that give different properties. By volume 8 parts mixed epoxy, 8 parts fumed silica, and 1 part milled glass fibers makes a good glue: stays were you put it, fills gaps, and is very strong.

          There are also a lot of structural fillets: coved beads of epoxy and fillers that go into corners where bulkheads and side panels meet. These at a lot of strength/stiffness to the structure.Report

          • Avatar Stillwater in reply to David Ryan
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            says:

            Yes, of course. That makes perfect sense. For some reason I was thinking fasteners would be necessary, but my own experience has taught me that isn’t so. It just took me a while to remember that.Report

          • Avatar Patrick Cahalan in reply to David Ryan
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            says:

            Total boat idiot question: what’s the lifetime of a skin?

            And how do you extend/replace it?  Do you have to take the old one off, or just…Report

            • Avatar David Ryan in reply to Patrick Cahalan
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              says:

              The safest answer is “It depends.” Some data points:

              My friend Bob built a Tiki 31 using exterior-grade plywood. 30 years later, the boat is still in service somewhere in France. For MON TIKI we’re using Bob’s epoxy application methods, but using marine-grade plywood from a more rot-resistant species.

              At the other end of the scale, I’ve build a handful of semi-disposable dories and dinks, using the cheapest materials and treating them very poorly. They seem to last about 5-10 years depending on use and luck.

              The two enemies are rot and sunlight.

              Rot is an internal enemy promoted by fresh water (leaks through the deck) and lack of air circullation. Good design and keeping fresh water out is the best preventative of rot.

              Sunlight is bad because of the UV component. UV breaks down epoxy, which exposees teh wood. A well-maintained paint job will protect epoxy from UV.

              Damage to a plywood skinned boat is easy to fix. Cut out the damage; use the hole as a template for the patch; back up the patch with glass and/or plywood; fair and paint the exterior.

              BTW, each hull of MON TIKI has five (5) separate water-right compartments. I won’t call her unsinkable, but she’s very well protected from sinking. If her skin was damaged, we could beach her at high tide and probably get the repair done before the next high tide.

               Report

              • Avatar James Hanley in reply to David Ryan
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                says:

                If her skin was damaged, we could beach her at high tide and probably get the repair done before the next high tide.

                Heh, that reminds me of the time I was using a folding canoe (skin stretched over a collapsible frame of aluminum poles) on the John Day River in Oregon.  5 miles down river (with 78 miles to go before the next road) I noticed the boat was filling with water.  A quick examination revealed that a shockcord holding one of the sets of aluminum framing poles together had broken, and where two poles came together (butt jointed, not a male/female connection) they had already rubbed a hole through the skin of the boat.  Oddly, when I rented the boat the day before, the shop had forgotten to give me the patch kit, but were still there after hours when I realized and rushed back.  So we taped up the pole joint with duct tape, then sewed a patch on the bottom of the boat by the light of the moon and a campfire.

                Pain in the ass, but a great memory.Report

              • Avatar Patrick Cahalan in reply to David Ryan
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                says:

                Comment lost in the database crash earlier today:

                So does the ply need to breathe?  Can you bypass the possibility of a rot problem by epoxying the interior?  I imagine there are cost implicationsReport

              • Avatar David Ryan in reply to Patrick Cahalan
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                says:

                The boat is “mumified” in epoxy inside and out, and as long as that stays intact, the wood undernegth is safe.

                The trouble comes when the coating is breeched, so care must be taken with the mounting of hardware, etc.

                Another nice thing about plywood is that worms hate the glue. Even if they get into the first layer, via a ding or damage or what not, the first glue line will stop them. So what you end up with is a material with the strength/weight ratio comparible to steel, but workable with handtools, and resistant to worm damage.

                BTW, my friend Bob is a big advocate of carbon fiber for much teh same reasons: very strong, but fabricatable with ordinary tools. Add Dyneema for rigging and you can make a very strong boat with little more than a skilsaw, squeegee and knitting needles.Report

              • Avatar James Hanley in reply to David Ryan
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                says:

                Can you buy dimensional and sheet carbon fiber?  Where?Report

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