Loading ...
Sorry, an error occurred while loading the content.

Re: Commonsense Skiff

Expand Messages
  • gbship
    ... strength. ... the ... Thanks everyone for the thought and advice. I should have explained better the use for this boat. It s for an expedition type
    Message 1 of 20 , Jul 3, 2005
    View Source
    • 0 Attachment
      >
      > That's what I was talking about when I mentioned penetration
      strength.
      > Sure a Gypsy isn't going to hit logs at 30 knots, but the scantlings
      > will already be redeuced in proportion to the speed. You can't let
      the
      > skins get too thin. 'Too thin' on foam is thinnner than 'too thin' on
      > ply. Avoiding that was where the extra weight came from.
      >
      > Chris

      Thanks everyone for the thought and advice. I should have explained
      better the use for this boat. It's for an expedition type competition
      of around 1,000 miles, give or take, for kayaks and small sailboats.
      Among the salient features, are you must beach launch your craft (You
      can use mechanical assistance, but you must carry whatever you use for
      the entire race), the ability to go under a 9-foot high bridge with 10-
      foot horizontal clearance, deal with open water and inland waterways
      churned by powerboat wakes, etc. This race is around the peninsula part
      of Florida, so at one point, competitors have to go up the St. Mary's
      river (in S. Georgia) and then portage their boats 40 MILES to the
      Suwanee. The kayakers balance their boats on a set of wheels, attach
      the bow to the back of their belt and walk it. They can also tow it
      with a folding bike -- as long as they carry the bike for the entire
      race. Obviously this won't work for sailboats, which even in a small
      size weigh much more. So those comeptitors are allowed to switch to a
      canoe for the necessary river portions and the portage. You can see the
      details at Watertribe.com, check the Ultra Florida Challenge section.
      We're only planning to do the shorter Everglades Challenge in 2006, in
      our Frolic2, but I'm intrigued with trying the longer race in 2007. My
      particular itch right now is to wonder if a small sailboat could be
      built light enough so that switching to the canoe would be unnecessary,
      even for the portage (which I would do with a bike!).

      But, alas, I know almost nothing of composite construction, which is
      why everyone's advice is so helpful and much appreciated. It does no
      good to have an ultralight hull if it's punctured by a razor sharp
      shell on an oyster bar, or a cypress knee or mangrove root in the
      Everglades, or by a rock or log in the Suwanee. The weight concern is
      why I've been mostly looking at ply instant-type boats in the 125 to
      150 pound range and wondering if that weight could be cut in half with
      composite construction. There are intriguing hints. For example, my 25-
      30 pound solid wood mast on the Rolic2 could be replaced by a carbon
      fiber spar that would weight less than 10 pounds. In Pete Goss' book
      about single handed racing around the world, he mentions that the bare
      hull of his 50 footer could be turned over by 6 husky guys --- about
      what the 1/2 inch ply/fiberglass bare hull weighs on our 30-footer
      (which is a Gypsy-type hull).

      BTW Graeme, thanks for the suggestion of the Zephyr, but I ruled that
      out because while it is an excellent daysailer and can handle some
      nasty weather, it doesn't row very well, possibly because the 16-inch
      sides are too high. (I had one for many years, and was very fond of it.)

      Gary Blankenship
    • John B. Trussell
      There have been various threads wich suggest that PCB doesn t design racing boats. You might take a look at Paul Gartside s web site--His Flashboat is a
      Message 2 of 20 , Jul 3, 2005
      View Source
      • 0 Attachment
        There have been various threads wich suggest that PCB doesn't design
        "racing" boats. You might take a look at Paul Gartside's web site--His
        Flashboat is a very light, very fast row boat and he has camp cruised around
        Alaska in it.

        It appears to me that the rules you described favor a kayak with a sail.
        I've always thought that a two person rowing boat would do well in this sort
        of race--the two rowers could alternate and maintain speed more or less
        continuously; they would also have the ability to row together and buck
        currents if needed.

        I'm way too old and decrepit to participate or even enjoy the kind of boat
        needed for this kind of event, but iy si fun to think about.

        John T
        ----- Original Message -----
        From: "gbship" <gbship@...>
        To: <bolger@yahoogroups.com>
        Sent: Sunday, July 03, 2005 7:57 AM
        Subject: [bolger] Re: Commonsense Skiff


        > >
        > > That's what I was talking about when I mentioned penetration
        > strength.
        > > Sure a Gypsy isn't going to hit logs at 30 knots, but the scantlings
        > > will already be redeuced in proportion to the speed. You can't let
        > the
        > > skins get too thin. 'Too thin' on foam is thinnner than 'too thin' on
        > > ply. Avoiding that was where the extra weight came from.
        > >
        > > Chris
        >
        > Thanks everyone for the thought and advice. I should have explained
        > better the use for this boat. It's for an expedition type competition
        > of around 1,000 miles, give or take, for kayaks and small sailboats.
        > Among the salient features, are you must beach launch your craft (You
        > can use mechanical assistance, but you must carry whatever you use for
        > the entire race), the ability to go under a 9-foot high bridge with 10-
        > foot horizontal clearance, deal with open water and inland waterways
        > churned by powerboat wakes, etc. This race is around the peninsula part
        > of Florida, so at one point, competitors have to go up the St. Mary's
        > river (in S. Georgia) and then portage their boats 40 MILES to the
        > Suwanee. The kayakers balance their boats on a set of wheels, attach
        > the bow to the back of their belt and walk it. They can also tow it
        > with a folding bike -- as long as they carry the bike for the entire
        > race. Obviously this won't work for sailboats, which even in a small
        > size weigh much more. So those comeptitors are allowed to switch to a
        > canoe for the necessary river portions and the portage. You can see the
        > details at Watertribe.com, check the Ultra Florida Challenge section.
        > We're only planning to do the shorter Everglades Challenge in 2006, in
        > our Frolic2, but I'm intrigued with trying the longer race in 2007. My
        > particular itch right now is to wonder if a small sailboat could be
        > built light enough so that switching to the canoe would be unnecessary,
        > even for the portage (which I would do with a bike!).
        >
        > But, alas, I know almost nothing of composite construction, which is
        > why everyone's advice is so helpful and much appreciated. It does no
        > good to have an ultralight hull if it's punctured by a razor sharp
        > shell on an oyster bar, or a cypress knee or mangrove root in the
        > Everglades, or by a rock or log in the Suwanee. The weight concern is
        > why I've been mostly looking at ply instant-type boats in the 125 to
        > 150 pound range and wondering if that weight could be cut in half with
        > composite construction. There are intriguing hints. For example, my 25-
        > 30 pound solid wood mast on the Rolic2 could be replaced by a carbon
        > fiber spar that would weight less than 10 pounds. In Pete Goss' book
        > about single handed racing around the world, he mentions that the bare
        > hull of his 50 footer could be turned over by 6 husky guys --- about
        > what the 1/2 inch ply/fiberglass bare hull weighs on our 30-footer
        > (which is a Gypsy-type hull).
        >
        > BTW Graeme, thanks for the suggestion of the Zephyr, but I ruled that
        > out because while it is an excellent daysailer and can handle some
        > nasty weather, it doesn't row very well, possibly because the 16-inch
        > sides are too high. (I had one for many years, and was very fond of it.)
        >
        > Gary Blankenship
        >
        >
        >
        >
        > 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
        >
        >
        >
        >
        >
        >
        >
        >
        > --
        > No virus found in this incoming message.
        > Checked by AVG Anti-Virus.
        > Version: 7.0.323 / Virus Database: 267.8.6/33 - Release Date: 6/28/2005
        >
      • Gary Lepak
        Gary, For what it s worth, I once built a Bolger Dolphin, (Small Boats, Design #259, 18 x 4 ) out of 3/8 Airex foam with two layers of 6 oz glass inside and
        Message 3 of 20 , Jul 3, 2005
        View Source
        • 0 Attachment
          Gary,

          For what it's worth, I once built a Bolger Dolphin, (Small Boats, Design
          #259, 18' x 4') out of 3/8" Airex foam with two layers of 6 oz glass inside
          and out. It was a stripped down rowboat version, no centerboard, rudder or
          rig. It weighed about a 100 lbs. I never weighed it, but two people could
          throw it over their heads like a canoe. It seemed quite tough, and I never
          worried about punctures or breakage. Of course it is a compound curved
          hull so the bulding took some time with lofting and moldmaking, but you
          would get a strong light hull this way. These days I would use Corefoam,
          though it is expensive.

          For a cheaper light boat that would be quicker to build I might try
          lapstrake plywood. You could vary the plank thickness, say 4 to 5 mm on the
          bottom and 3mm topsides.

          Gary Lepak
          Port Angeles, WA
        • Howard Stephenson
          To see a boat that is suitable for South Georgia, go to: http://www.ibiblio.org/ebooks/Shackleton/South/057.jpg Howard ;-]
          Message 4 of 20 , Jul 3, 2005
          View Source
          • 0 Attachment
            To see a boat that is suitable for South Georgia, go to:

            http://www.ibiblio.org/ebooks/Shackleton/South/057.jpg

            Howard ;-]

            --- In bolger@yahoogroups.com, "gbship" <gbship@c...> wrote:

            > so at one point, competitors have to go up the St. Mary's
            > river (in S. Georgia) and then portage their boats 40 MILES
          • graeme19121984
            Perhaps *the* small boat team time trial endurance event.
            Message 5 of 20 , Jul 3, 2005
            View Source
            • 0 Attachment
              Perhaps *the* small boat team time trial endurance event.

              --- In bolger@yahoogroups.com, "Howard Stephenson" <stephensonhw@a...>
              wrote:
              > To see a boat that is suitable for South Georgia, go to:
              >
              > http://www.ibiblio.org/ebooks/Shackleton/South/057.jpg
              >
              > Howard ;-]
              >
              > --- In bolger@yahoogroups.com, "gbship" <gbship@c...> wrote:
              >
              > > so at one point, competitors have to go up the St. Mary's
              > > river (in S. Georgia) and then portage their boats 40 MILES
            • James Greene
              Wow, when I was thinking abut glass over foam construction I was considering 1 inch foam or thicker for the hulls. You guys are using foam that s less than
              Message 6 of 20 , Jul 3, 2005
              View Source
              • 0 Attachment
                Wow, when I was thinking abut glass over foam construction I was
                considering 1 inch foam or thicker for the hulls. You guys are using
                foam that's less than half this thickness! Interesting ...

                James Greene


                On Jul 3, 2005, at 09:58, gbship wrote:

                > A friend
                > laminated a couple layers of glass on either side of 3/8 inch foam (I
                > think that was the thickness) and you could whack it with a hammer
                > without damage and it was considerably lighter than a ply sandwich
                > would have been. I made some hatches for our Frolic2 of glass over 1/4-
                > inch foam and those are reasonably strong, and very light, but not
                > strong enough for use for a hull.
              • James Greene
                ... I wonder if the cheapest available foam might not be good enough for most small boats, provided it fills the void between the inner and outer skins and
                Message 7 of 20 , Jul 3, 2005
                View Source
                • 0 Attachment
                  > These days I would use Corefoam,
                  > though it is expensive.

                  I wonder if the cheapest available foam might not be "good enough" for
                  most small boats, provided it fills the void between the inner and
                  outer skins and does not separate from them. Does this leave out good
                  old fashioned styrofoam I wonder?

                  James Greene
                • Clyde Wisner
                  I think I used inch and a half foam for my Brick and had to use a lot of glass and epoxy to get strength to stand in. I also made a deck of sorts from 1/4 ply
                  Message 8 of 20 , Jul 4, 2005
                  View Source
                  • 0 Attachment
                    I think I used inch and a half foam for my Brick and had to use a lot of
                    glass and epoxy to get strength to stand in. I also made a deck of sorts
                    from 1/4 ply so the sides wouldn't bolge out. Overall, not worth the
                    money in glass and epoxy, and the trouble. If you do go forward, I would
                    think a multi
                    chine rather than large flat areas like the bottom of a Brick. My foam
                    Brick floats upside down of course and almost floated away during
                    Isabell, which might not have been bad. Clyde.


                    James Greene wrote:

                    > > These days I would use Corefoam,
                    > > though it is expensive.
                    >
                    > I wonder if the cheapest available foam might not be "good enough" for
                    > most small boats, provided it fills the void between the inner and
                    > outer skins and does not separate from them. Does this leave out good
                    > old fashioned styrofoam I wonder?
                    >
                    > James Greene
                    >
                    >
                    >
                    >
                    >
                    >
                    > 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
                    >
                    > * Visit your group "bolger
                    > <http://groups.yahoo.com/group/bolger>" on the web.
                    >
                    > * To unsubscribe from this group, send an email to:
                    > bolger-unsubscribe@yahoogroups.com
                    > <mailto:bolger-unsubscribe@yahoogroups.com?subject=Unsubscribe>
                    >
                    > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
                    > Service <http://docs.yahoo.com/info/terms/>.
                    >
                    >
                    > ------------------------------------------------------------------------
                    >



                    [Non-text portions of this message have been removed]
                  • Chris Stewart
                    ... the ... at ... side. Consider skin on frame constuction using 26 ounce double ply woven nylon skin. Quoting from UMIAK An Illustrated Guide by Skip
                    Message 9 of 20 , Jul 4, 2005
                    View Source
                    • 0 Attachment
                      --- In bolger@yahoogroups.com, Chris Lasdauskas <cml@t...> wrote:
                      > 'To demonstrate his point, the builder took a hammer and wacked at
                      the
                      > sample panel mightily. With the hammer bouncing off harmlessly, he
                      > offered it confidently to the skeptical architect. Taking the hammer,
                      > the architect turned it claw-side down and -— with virtually no force
                      at
                      > all -— drove it right through Kevlar, the foam, and out the other
                      side.


                      Consider skin on frame constuction using 26 ounce double ply woven
                      nylon skin. Quoting from "UMIAK An Illustrated Guide" by Skip Snaith:
                      "The 26-ounce double-weave nylon skin on Tim's boat was incredibly
                      tough; you could hit it with the claw end of a hammer as hard as you
                      liked, and the hammer would bounce back."

                      Skin on frame can produce very light boats. Platt Monfort's Geodesic
                      Aerolight boats are incredibly light, but probably not strong enough
                      for the Watertribe Challenge. Up the scantlings a bit, with the frame
                      lashed rather than glued to preserve flexibility, and use a much
                      tougher skin and you'd end up with a light, resilient boat.

                      Chris Stewart
                    • Gary Lepak
                      James, The boatbuilding foams like Airex, Corecell and Divinicell are more dense than styrofoam. 5 to 8 lbs per cubic ft. compared to 1.1 (white) to 2 (pink
                      Message 10 of 20 , Jul 4, 2005
                      View Source
                      • 0 Attachment
                        James,
                        The boatbuilding foams like Airex, Corecell and Divinicell are more dense
                        than styrofoam. 5 to 8 lbs per cubic ft. compared to 1.1 (white) to 2
                        (pink or blue). The lighter the foam the thicker the skin needs to be to
                        maintain the bond when struck. I've built two boats from blue foam, a tri
                        that didn't last very long made of 1" thick foam with glass/epoxy skins,
                        and a solid foam paddleboard I still have. The board has two layers of 6
                        oz glass in epoxy resin on the bottom and a 3mm ply deck. The two layers of
                        6 are about minimum I think, and it is still easily punctured or dented. It
                        just doesn't matter much if it is, as it still floats, being solid foam. If
                        you are always building boats with epoxy anyway, you fill the dings easily.
                        The ply deck seems to take a lot of abuse without delaminating though, and
                        could make a good boat with 1" foam inside 3mm ply with glass inside, but
                        would probably weigh as much as 1/4" ply. I like using the blue foam though
                        and still use it for things like outrigger floats or sponsons, i.e. solid
                        foam objects with glass skin, rather than as a foam sandwich hull skin .
                        Gary Lepak


                        ----- Original Message ----- > I wonder if the cheapest available foam might
                        not be "good enough" for
                        > most small boats, provided it fills the void between the inner and
                        > outer skins and does not separate from them. Does this leave out good
                        > old fashioned styrofoam I wonder?
                        >
                        > James Greene
                      Your message has been successfully submitted and would be delivered to recipients shortly.