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Re: Birdwatcher II - others being built?

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  • Bob Larkin
    ...
    Message 1 of 20 , Jan 1, 2005
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      --- In
      <http://groups.yahoo.com/group/bolger/message//group/bolger/post?postID=r6zJpKzH9fTObSDbSfOpuPHJO4DWtXGEyYpkGGno3lSIVLWR8ShNO6ScJw-6M5AlIT8KmpC-Be9DS6M56LSSqTk>bolger@yahoogroups.com,
      "Nels"
      <<http://groups.yahoo.com/group/bolger/message//group/bolger/post?postID=9_Go02GuNDvzvgm1ONUd_U0ZEx8HYPaJaNGERdi6_rVYmQ_hvfwMZnOgUix0TOCxFi5-haJ5Vy0XqwA>arvent@h...>
      wrote:

      >Good for you! You have made a great choice. There is one being built
      >in TN I believe.
      >
      >The fellow's name is David Lipsey. I will forward his e-mail to you
      >off-list and I am certain he would love to hear from you. He sounds
      >like a real pirate as he has at least two other boats in various
      >stages of completion.

      Thanks Nels for the lead. I will report back about his progress, assuming I
      reach him. I have the email address that you sent--thanks.
      >
      >I believe he has changed the scantlings somewhat because of the
      >available materials. He is using 3/8" for the outer layer, 3/4"
      >longitudinals and foam thickness and 1/4" linings. That sounds
      >excellent to me actually.
      >
      This is an interesting question. I have given it some thought, and plan to
      go with Bolger's design of 1/4" and 1/8" (actually 3 mm) outer and inner,
      along with 1 inch foam. Let me put down my understanding of composite
      walls, and see if I have it close to right (I would also like to run this
      past David Lipsey and understand his choices).

      When the side is hit by water, the outer wall will want to bend in. As this
      happens, the inner wall comes under tension, where it is strong. This inner
      wall is important in preventing inward deflection.

      The outer wall also plays a role in that it does have strength in
      compression. If both walls are increased in thickness by 1.5, the strength
      of the boat side is also increase by 1.5.

      The overall resistance to bending of the side is strongly dependent on the
      foam thickness, going as the square of this. So 1" foam produces a wall
      approaching twice the strength of 3/4". This assumes the inner wall won't
      fail in tension, which would be interesting to study!

      Thus, the Bolger construction would be stronger by 4/3 squared times 1/1.5
      or about 18 percent.

      This also assumes that the foam does not fail by being squished. I think
      this may be a reasonable assumption. The foam is not resistant to a sharp
      object, but if the load is distributed over a large area, as the walls tend
      to do, it becomes difficult to compress.

      In fact, the whole side, especially with the 1/4" outer wall, can be
      destroyed by a concentrated load, like an errant log. Part of the defense
      is the sharpie shape and the hope of taking this impact almost all edgewise
      on the bottom. Or avoiding the log!

      The other side of the equation is weight, and the BW concept wants to
      concentrate the weight in the bottom and the movable objects like
      people. The lighter the sides, the better. This pushes for thin walls, as
      does the cost of wood.

      Are there any composite structure designers to keep this straight? I'm an
      amateur at this stuff, with a couple of old books.

      And Happy 2005 to All!

      Bob
    • Nels
      ... plan to ... inner, ... composite ... run this ... Hi Bob, I would just like to say that all you spoke of is probably correct and I know David would agree.
      Message 2 of 20 , Jan 1, 2005
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        --- In bolger@yahoogroups.com, Bob Larkin <boblark@p...> wrote:
        > This is an interesting question. I have given it some thought, and
        plan to
        > go with Bolger's design of 1/4" and 1/8" (actually 3 mm) outer and
        inner,
        > along with 1 inch foam. Let me put down my understanding of
        composite
        > walls, and see if I have it close to right (I would also like to
        run this
        > past David Lipsey and understand his choices).
        >
        Hi Bob,

        I would just like to say that all you spoke of is probably correct
        and I know David would agree. His decisions were based on available
        materials and limited resources and he is in no way endorsing them
        for others. He estimates that the boat will be about 40 lb heavier
        and have 25% less floatation in the hull. Of course BWI has no hull
        floatation except in the ends so that can be easily made up for. And
        the end weight will also depend on how much glass is added. If I was
        to use 3/8" MDO I would only glass below the waterline. If I used
        1/4" I would glass the entire exterior. The weight would probably end
        up the same. Of course it also depends on what kind of plywood one
        uses.

        3/4' foam and 1X lumber (which is only 3/4" thick) are both far
        cheaper than the 1" thickness items. David bought his at Home Despot.

        I am not certain if the hull is a TRUE ply/foam/ply sandwich
        construction as the foam is not laminated to the plywood. Or is it? I
        am not sure if it is meant to be a structural component. Of course
        the doubled ply is really strong by itself - even without the foam!

        A great asset of the design is it's 6" draft and low momemntum which
        means it will pass right over most obstructions or just bounce off
        with nary more than a scratch. All blows will be glancing with the
        exception of the bottom and chimes and these are easily reinforced
        with extra glass taping, or even a sacrificial skid.

        How about UMHD strakes like Bruce used on Rose?

        Perhaps Bruce can share with us how these were attached?

        I am really curious about the slot closure system. Can you elaborate
        on that?

        Happy 2005, Nels
      • Bob Larkin
        ... Hi Jim - sounds like a fine project! I talked to my wife about adding a second set of oar ports in BW-2, but I didn t detect much interest!! Bob
        Message 3 of 20 , Jan 1, 2005
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          On Fri, 31 Dec 2004 Jim Clements wrote:

          >I'm about to take the plunge to build the Amhearst Galley with is a longer
          >version of the Birdwatcher for 8 rowers. Good luck with yours. I hope
          >I'm not getting in over my head.

          Hi Jim - sounds like a fine project! I talked to my wife about adding a
          second set of oar ports in BW-2, but I didn't detect much interest!!

          Bob
        • Harry James
          This one has been perking around in my thoughts for quite a while, as I am feeling particularly maudlin this fine New Years morning I will try and get it down
          Message 4 of 20 , Jan 1, 2005
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            This one has been perking around in my thoughts for quite a while, as I
            am feeling particularly maudlin this fine New Years morning I will try
            and get it down coherently.

            In early September last year I returned from a years National Guard
            mobilization. I had stopped the emails from my various Yahoo groups when
            I was mobilized. While going through demobilization at Ft McCoy
            Wisconsin I was able to get on line and I thought --what the heck-- I
            will reactivate my Yahoo accounts. I got emails started again from all
            of them and then started to read back the last few days of messages on
            the Bolger list. There you all were-- Peter L, the Bruce H's, David R
            and Sue F with the plans still not finished for the I -60 , many other
            familiar names, just like no time had passed at all. It was a tremendous
            emotional impact, I was back in a part of the world I had been
            completely separated from.

            A friend caught me furtively wiping my eyes and asked me what was wrong.
            The answer was "absolutely nothing is wrong, things are very right". I
            was really coming home.

            This group has always been a little different from other groups that I
            belong to, lots of adjective's come to mind, helpful, humorous,
            knowlegable, I have had a hard time pinning this one down. Mostly you
            are just human the way we want humans to be, all the positive stuff none
            of the negative. You are the people I would want as neighbors.

            So have a happy Bolger new year, may your tools be sharp and your
            plywood void less.

            Harry James from Juneau where the Taku is blowing, the weak winter sun
            is shining and the shop is warm and full of wood.
          • Philip Smith
            You think we re great? I hope you get a chance to meet Phil and Susanne! They are some of the nicest and smartest people it will ever be your pleasure to meet.
            Message 5 of 20 , Jan 1, 2005
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              You think we're great? I hope you get a chance to meet
              Phil and Susanne! They are some of the nicest and
              smartest people it will ever be your pleasure to meet.
              Not to mention creative, atistic, funny, considerate,
              insightful and more, much more.

              Welcome back, Happy New Year, and best of luck.

              Phil Smith
            • jhkohnen@boat-links.com
              What does Bolger recommend using for the foam? I gave some thought to plywood/foam composite construction a few years ago when I tried building a Brick with
              Message 6 of 20 , Jan 1, 2005
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                What does Bolger recommend using for the foam? I gave some thought to
                plywood/foam composite construction a few years ago when I tried building a
                Brick with composite sides (I made some errors and finally threw my hands up
                in disgust and scrapped it). For my use I figured insulation foam sheets
                would work fine, but for something more ambitious I wondered if they had
                enough strength. When stressed would the foam fail internally? Would
                repeated stresses cause cumulative damage until you just had foam dust
                between the sheets of plywood? Perhaps I was being overly pessimistic...

                On Sat, 01 Jan 2005 10:10:44 -0800, Bob L wrote:
                > ...
                > This also assumes that the foam does not fail by being squished. I think
                > this may be a reasonable assumption. The foam is not resistant to a sharp
                > object, but if the load is distributed over a large area, as the walls
                tend
                > to do, it becomes difficult to compress.
                > ...

                --
                John <jkohnen@...>
                http://www.boat-links.com/
                It s a damn poor mind that can think of only one way to spell a word!
                <Attributed to Andrew Jackson>
              • Nels
                ... If you check the links on this site there is a folder giving a list of materials for BWII, including the brand name of the foam. If you Google you will
                Message 7 of 20 , Jan 1, 2005
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                  --- In bolger@yahoogroups.com, jhkohnen@b... wrote:
                  > What does Bolger recommend using for the foam?

                  If you check the links on this site there is a folder giving a list
                  of materials for BWII, including the brand name of the foam.

                  If you Google you will find there are some very impressive home-
                  building insulation foams. Limited only by your pocket book. Some
                  have instructions on the net showing which adhesives to use and the
                  type of strapping. To me these foams will stand up to boat use and
                  are well in keeping with Bolger boxes.

                  Cheers, Nels
                • Philip Smith
                  When choosing a foam you should also consider any toxic fumes it might give off if it and your boat happen to catch fire. Different foams have very different
                  Message 8 of 20 , Jan 1, 2005
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                    When choosing a foam you should also consider any
                    toxic fumes it might give off if it and your boat
                    happen to catch fire. Different foams have very
                    different levels of toxicity.

                    You may want to give yourself a chance to drown before
                    you die from poisoning.

                    Phil Smith
                  • Peter Lenihan
                    ... Hmmmmm.....seems to me that if your boat is on FIRE(yikes!) you ve really got your hands full and your world is not made better with the presence of less
                    Message 9 of 20 , Jan 1, 2005
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                      --- In bolger@yahoogroups.com, Philip Smith <pbs@w...> wrote:
                      > When choosing a foam you should also consider any
                      > toxic fumes it might give off if it and your boat
                      > happen to catch fire.

                      Hmmmmm.....seems to me that if your boat is on FIRE(yikes!) you've
                      really got your hands full and your world is not made better with
                      the presence of less toxic elements either within the hull materials
                      and your boats contents :-0
                      However, some plastics do off-gas for many,many months and this may
                      be more delitrious to ones health in the long run......I think :-)

                      Sincerely,

                      Peter Lenihan
                    • Bob Larkin
                      ... The installation of the foam presents several interesting issues. I have not seen Bolger address them specifically, but it strikes me as most desirable to
                      Message 10 of 20 , Jan 1, 2005
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                        Nels wrote:
                        >I am not certain if the hull is a TRUE ply/foam/ply sandwich
                        >construction as the foam is not laminated to the plywood. Or is it? I
                        >am not sure if it is meant to be a structural component. Of course
                        >the doubled ply is really strong by itself - even without the foam!

                        The installation of the foam presents several interesting issues. I have
                        not seen Bolger address them specifically, but it strikes me as most
                        desirable to make the foam and plywood into a sandwich, with strong
                        adhesive. Structurally, this increases the strength for forces pulling from
                        the outside, that may occur when the boat is heeled. Also important, is to
                        prevent voids that can collect water. I was planning to use some 2-part
                        expanding foam in small left-over volumes around the foam sheets.

                        I have used the expanding foam before, and I remember problems in
                        controlling the stuff! It sometimes didn't want to go where you wanted,
                        and other times wanted to sneak out through cracks. I want to have all the
                        expanding foam in place before putting the inner plywood on. This allows
                        cleanup and redo of missed areas. The expanding foam I used also required
                        good ventilation! Maybe they have better products now, as this was 15
                        years ago.

                        John K., I plan to do some small test panels with the foam sandwich. I can
                        drop off a sample for you to play with if you want? This will probably be
                        early Feb. You will probably think of good ways to torture the stuff.

                        >If I was
                        >to use 3/8" MDO I would only glass below the waterline. If I used
                        >1/4" I would glass the entire exterior. The weight would probably end
                        >up the same. Of course it also depends on what kind of plywood one
                        >uses.

                        Nels, on the build up for the sides, I now understand the constraints that
                        David was working with! Thanks. I agree on the use of glass for the 1/4"
                        plywood, but it probably could be thinner than the bottom.

                        >
                        >A great asset of the design is it's 6" draft and low momemntum which
                        >means it will pass right over most obstructions or just bounce off
                        >with nary more than a scratch. All blows will be glancing with the
                        >exception of the bottom and chimes and these are easily reinforced
                        >with extra glass taping, or even a sacrificial skid.
                        >
                        >How about UMHD strakes like Bruce used on Rose?

                        Yes, and it sounds like another good area to learn more about. I have used
                        it for small sliding parts---but why not the boat. BTW, I plan to take the
                        boat all the way to the water on the trailer ;-)

                        I am really curious about the slot closure system. Can you elaborate
                        on that?

                        Bolger does not overburden us with details for the hard hatches. Made up in
                        four overlapping sections, they are again fabricated from a sandwich of
                        1-inch foam with 3mm plywood top and bottom. The aft section has a 32-inch
                        cover that hinges forward. They sit just high enough over the
                        standing-room comings to allow drainage between sections. There are no
                        suggestions for stowage. As drawn, they are too long to fit in the forward
                        compartment.

                        These hatches are somewhat large, typically 2x4 feet. I will try to report
                        later on their apparent ability to bear weight. Again this is the sandwich
                        question. They also are easy to modify/replace, if needed.

                        My present plan is to build this type of hatch for the forward and aft
                        compartments and start out with a minimal soft cover for the middle (plus a
                        middle tent for camping). I'm still looking for proper latches.

                        Many thanks to all for the fine comments!

                        Bob
                      • Bruce Hallman
                        ... Having UHMW skid strips on the boat was also useful when pushing/pulling the boat around in my shop and driveway during construction. It makes
                        Message 11 of 20 , Jan 2, 2005
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                          > >How about UMHD strakes like Bruce used on Rose?
                          >
                          > Yes, and it sounds like another good area to learn more about. I have used
                          > it for small sliding parts---but why not the boat. BTW, I plan to take the
                          > boat all the way to the water on the trailer ;-)

                          <grin> Having UHMW skid strips on the boat was also useful when
                          pushing/pulling the boat around in my shop and driveway during
                          construction. It makes sense to reinforce the 'points of contact'
                          of the hull, the center bottom of the fin keel, and the center
                          edges of the chines.
                        • Howard Stephenson
                          A nice tribute to this group, Harry. But do you still keep up the trumpet playing? One of my model yacht racing friends goes by the name of Les Brown. (The
                          Message 12 of 20 , Jan 2, 2005
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                            A nice tribute to this group, Harry. But do you still keep up the
                            trumpet playing? One of my model yacht racing friends goes by the
                            name of Les Brown. (The above will be a mystery to most people under
                            about 60).

                            Howard

                            --- In bolger@yahoogroups.com, Harry James
                            > The answer was "absolutely nothing is wrong, things are very
                            > right". I was really coming home.
                          • Harry James
                            My very first memory was going into the hospital at the age of four to get my tonsils out and the nurse asking me where s your trumpet Harry . I have heard it
                            Message 13 of 20 , Jan 2, 2005
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                              My very first memory was going into the hospital at the age of four to
                              get my tonsils out and the nurse asking me "where's your trumpet Harry".
                              I have heard it one or two times since.

                              For the record I play Saxophone and 5 string Banjo, and because I am
                              partly Welsh, I have to sing.

                              HJ

                              Howard Stephenson wrote:

                              >A nice tribute to this group, Harry. But do you still keep up the
                              >trumpet playing? One of my model yacht racing friends goes by the
                              >name of Les Brown. (The above will be a mystery to most people under
                              >about 60).
                              >
                              >Howard
                              >
                              >--- In bolger@yahoogroups.com, Harry James
                              >
                              >
                              >>The answer was "absolutely nothing is wrong, things are very
                              >>right". I was really coming home.
                              >>
                              >>
                              >
                              >
                              >
                              >
                              >
                              >
                              >Bolger rules!!!
                              >- no cursing, flaming, trolling, spamming, or flogging dead horses
                              >- stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
                              >- Pls add your comments at the TOP, SIGN your posts, and snip away
                              >- Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
                              >- Unsubscribe: bolger-unsubscribe@yahoogroups.com
                              >- Open discussion: bolger_coffee_lounge-subscribe@yahoogroups.com
                              >Yahoo! Groups Links
                              >
                              >
                              >
                              >
                              >
                              >
                              >
                              >.
                              >
                              >
                              >
                            • David
                              ... ******************* Howard, Hold up there hepcat. Mostly I m a lurker here, but couldn t let that one go. I m substantially under 60, recently turned 39
                              Message 14 of 20 , Jan 2, 2005
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                                --- In bolger@yahoogroups.com, "Howard Stephenson" <stephensonhw@a...>
                                wrote:
                                >
                                > A nice tribute to this group, Harry. But do you still keep up the
                                > trumpet playing? One of my model yacht racing friends goes by the
                                > name of Les Brown. (The above will be a mystery to most people under
                                > about 60).
                                >
                                > Howard
                                >
                                > --- In bolger@yahoogroups.com, Harry James
                                > > The answer was "absolutely nothing is wrong, things are very
                                > > right". I was really coming home.

                                *******************

                                Howard,

                                Hold up there hepcat. Mostly I'm a lurker here, but couldn't let that
                                one go. I'm substantially under 60, recently turned 39 (again), and I
                                certainly know Les Brown & his band of reknown. Of course, I played
                                trumpet for a few years. Right now I'm listening to a random selection
                                of: Glenn Miller; Miles Davis; Benny Goodman; Cab Calloway; Duke
                                Ellington. This kind of music keeps me hopping while I work on the
                                boat we're currently building.

                                Cheers,
                                David Graybeal
                                Portland, OR.

                                "You know what I miss about the good old days? I wasn't so good & I
                                wasn't so old" - Groucho Marx
                              • pvanderwaart
                                ... Once upon a time, circa 1970, I was in an East Asian Republic, courtesy of Uncle Sam, serving as bandsman for the US Army. As was his habit, fellow name of
                                Message 15 of 20 , Jan 2, 2005
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                                  > I certainly know Les Brown & his band of reknown.

                                  Once upon a time, circa 1970, I was in an East Asian Republic,
                                  courtesy of Uncle Sam, serving as bandsman for the US Army. As was
                                  his habit, fellow name of Bob Hope brought a song and humor show into
                                  the field. It fell to us to play for the audience for the few hours
                                  that it took to get several thousand troops in from the jungle (well,
                                  brush).

                                  So, I saw Les Brown, as well as his band of reknown, in person.

                                  Also, Neil Armstrong, Theresa Brewer, Connie Stevens, and a lovely
                                  German (or possibly Austrian) Miss World.

                                  Peter
                                • David
                                  ... *************** Ah, yes, but... are you under 60 - as I suspect?
                                  Message 16 of 20 , Jan 2, 2005
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                                    --- In bolger@yahoogroups.com, "pvanderwaart" <pvanderwaart@y wrote:>
                                    >
                                    > Once upon a time, circa 1970, I was in an East Asian Republic,
                                    > courtesy of Uncle Sam, serving as bandsman for the US Army. As was
                                    > his habit, fellow name of Bob Hope brought a song and humor show into
                                    > the field. It fell to us to play for the audience for the few hours
                                    > that it took to get several thousand troops in from the jungle (well,
                                    > brush).
                                    >
                                    > So, I saw Les Brown, as well as his band of reknown, in person.
                                    >
                                    > Also, Neil Armstrong, Theresa Brewer, Connie Stevens, and a lovely
                                    > German (or possibly Austrian) Miss World.
                                    >
                                    > Peter

                                    ***************

                                    Ah, yes, but... are you under 60 - as I suspect?
                                  • Bryant Owen
                                    Being partly Welsh, as my dad had it, means you HAVE to sing, doesn t necessarily means that you re good at it . Hey, I m not 60 (yet). My mom was a real
                                    Message 17 of 20 , Jan 2, 2005
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                                      Being partly Welsh, as my dad had it, means you HAVE to sing, doesn't
                                      necessarily means that you're good at it <g>.

                                      Hey, I'm not 60 (yet). My mom was a real bobbysockser, had tons of
                                      Frank's records - and lots of Big Band stuff too. Some of us Baby
                                      Boomers had lots of opportunities to listen to this stuff, just like
                                      my kids had to hear all that sixties crap I played.

                                      Bryant OWEN (probably a distant relation to George Owen, NA)

                                      --- In bolger@yahoogroups.com, Harry James <welshman@p...> wrote:
                                      > My very first memory was going into the hospital at the age of four
                                      to
                                      > get my tonsils out and the nurse asking me "where's your trumpet
                                      Harry".
                                      > I have heard it one or two times since.
                                      >
                                      > For the record I play Saxophone and 5 string Banjo, and because I
                                      am
                                      > partly Welsh, I have to sing.
                                      >
                                      > HJ
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