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Re: [bolger] Glassing for impact resistance/resistance is useless

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  • Richard Spelling
    The interesting thing about glassing the hull for impact resistance is that we all put it on the wrong side! Durring a big impact the outside of the hull is
    Message 1 of 10 , Nov 2, 2002
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      The interesting thing about glassing the hull for "impact resistance" is
      that we all put it on the wrong side! Durring a big impact the outside of
      the hull is under compression, and the inside is under tension. If we put
      the glass on the inside, it would have a much better chance of preventing a
      stump from joining you in the boat.

      Glass on the outside is handy to keep big chunks of plywood from being
      ripped out by sharp rocks, though. Kevlar would be even better.

      Then again, on thin hulls, 5mm lauan comes to mind, I've come close to
      putting a knee through the bottom of the hull. Even a light glass layer on
      the bottom would help prevent that.

      ----- Original Message -----
      From: "David Ryan" <david@...>
      To: <bolger@yahoogroups.com>
      Sent: Saturday, November 02, 2002 6:00 AM
      Subject: [bolger] Glassing for impact resistance/resistance is useless


      | FBBB --
      |
      | As you all know, I am a big advocate of glassing over plywood
      | anywhere the sun beat down on it. Theres's simply no comparison
      | between how long a prime&paint finish lasts vs. glass/epoxy/paint.
      |
      | However, I've had no good experience "glassing for impact resistance"
      | on my small boats.
      |
      | The inevitable result is the glass fails at the point of impact,
      | allowing water to creep under the glass job. Over time, the results
      | of this are even worse than using no glass at all! Glass delaminates,
      | trapped water does nasty things to the wood, etc.
      |
      | Now that doesn't mean I don't double up around chines, and other
      | pointy parts of the boat. But I don't expect my "impact protection
      | either." Perhaps on a larger craft you could build up the glass
      | enough to provide some meaningful protection, but I think on a small,
      | cheap boat it's both cost and weight prohibitive.
      |
      | YIBB,
      |
      | David
      | --
      |
      | C.E.P.
      | 415 W.46th Street
      | New York, New York 10036
      | http://www.crumblingempire.com
      | Mobile (646) 325-8325
      | Office (212) 247-0296
      |
      |
      | Bolger rules!!!
      | - no cursing, flaming, trolling, spamming, or flogging dead horses
      | - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
      | - add your comments at the TOP and SIGN your posts and <snip> away
      | - To order 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
      |
      | Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
      |
      |
    • Ned Asplundh
      Lookee here: http://www.oneoceankayaks.com/Abrasion.htm ...for one builder s take on the good, bad and ugly of differing reinforcement fabrics. ...
      Message 2 of 10 , Nov 2, 2002
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        Lookee here:

        http://www.oneoceankayaks.com/Abrasion.htm

        ...for one builder's take on the "good, bad and ugly" of differing
        reinforcement fabrics.

        --- In bolger@y..., David Ryan <david@c...> wrote:
        > FBBB --
        >
        > As you all know, I am a big advocate of glassing over plywood
        > anywhere the sun beat down on it. Theres's simply no comparison
        > between how long a prime&paint finish lasts vs. glass/epoxy/paint.
        >
        > However, I've had no good experience "glassing for impact
        resistance"
        > on my small boats.
        >
        > The inevitable result is the glass fails at the point of impact,
        > allowing water to creep under the glass job. Over time, the results
        > of this are even worse than using no glass at all! Glass
        delaminates,
        > trapped water does nasty things to the wood, etc.
        >
        > Now that doesn't mean I don't double up around chines, and other
        > pointy parts of the boat. But I don't expect my "impact protection
        > either." Perhaps on a larger craft you could build up the glass
        > enough to provide some meaningful protection, but I think on a
        small,
        > cheap boat it's both cost and weight prohibitive.
        >
        > YIBB,
        >
        > David
        > --
        >
        > C.E.P.
        > 415 W.46th Street
        > New York, New York 10036
        > http://www.crumblingempire.com
        > Mobile (646) 325-8325
        > Office (212) 247-0296
      • Jeff Blunck
        I just visited this site and one of us is mistaken. I purchased Olefin from Defender and it looks and lays up exactly like the Dynel shown on this site. Also,
        Message 3 of 10 , Nov 2, 2002
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          I just visited this site and one of us is mistaken. I purchased Olefin from
          Defender and it looks and lays up exactly like the Dynel shown on this site.
          Also, the Defender catalog list this type of picture for Olefin.

          I went out in the garage and checked the box and packing on the 75 yard roll
          I have been using and it's marked Olefin.

          It's possible this site has the Dynel and Olefin mixed up.

          Interesting.

          Jeff


          ----- Original Message -----
          From: "Ned Asplundh" <nasplundh@...>
          To: <bolger@yahoogroups.com>
          Sent: Saturday, November 02, 2002 6:09 PM
          Subject: [bolger] Re: Glassing for impact resistance/resistance is useless


          > Lookee here:
          >
          > http://www.oneoceankayaks.com/Abrasion.htm
          >
          > ...for one builder's take on the "good, bad and ugly" of differing
          > reinforcement fabrics.
          >
          > --- In bolger@y..., David Ryan <david@c...> wrote:
          > > FBBB --
          > >
          > > As you all know, I am a big advocate of glassing over plywood
          > > anywhere the sun beat down on it. Theres's simply no comparison
          > > between how long a prime&paint finish lasts vs. glass/epoxy/paint.
          > >
          > > However, I've had no good experience "glassing for impact
          > resistance"
          > > on my small boats.
          > >
          > > The inevitable result is the glass fails at the point of impact,
          > > allowing water to creep under the glass job. Over time, the results
          > > of this are even worse than using no glass at all! Glass
          > delaminates,
          > > trapped water does nasty things to the wood, etc.
          > >
          > > Now that doesn't mean I don't double up around chines, and other
          > > pointy parts of the boat. But I don't expect my "impact protection
          > > either." Perhaps on a larger craft you could build up the glass
          > > enough to provide some meaningful protection, but I think on a
          > small,
          > > cheap boat it's both cost and weight prohibitive.
          > >
          > > YIBB,
          > >
          > > David
          > > --
          > >
          > > C.E.P.
          > > 415 W.46th Street
          > > New York, New York 10036
          > > http://www.crumblingempire.com
          > > Mobile (646) 325-8325
          > > Office (212) 247-0296
          >
          >
          > Bolger rules!!!
          > - no cursing, flaming, trolling, spamming, or flogging dead horses
          > - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
          > - add your comments at the TOP and SIGN your posts and <snip> away
          > - To order 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
          >
          > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
          >
          >
          >
        • Nels
          ... delaminates, ... I wonder David if the plywood is sucking out some of the resin from the glass as it cures? Do you precoat the plywood first with a
          Message 4 of 10 , Nov 2, 2002
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            --- In bolger@y..., David Ryan <david@c...> wrote:
            > FBBB --
            >
            > The inevitable result is the glass fails at the point of impact,
            > allowing water to creep under the glass job. Over time, the results
            > of this are even worse than using no glass at all! Glass
            delaminates,
            > trapped water does nasty things to the wood, etc.
            >
            >> C.E.P.
            > 415 W.46th Street
            > New York, New York 10036
            > http://www.crumblingempire.com
            > Mobile (646) 325-8325
            > Office (212) 247-0296

            I wonder David if the plywood is sucking out some of the resin from
            the glass as it cures? Do you precoat the plywood first with a
            penetrating resin to prevent this?

            System Three has a special resin for this purpose.There should
            therefor be a molecular bonding between that inner glass surface and
            the plywood cellular structure. This is one reason why epoxy is
            superior to polyester resin.

            Nels
          • John Cupp
            I continue to advocate UHMW for all the reasons sited in this thread. With UHMW your boat acts like it has a Teflon shell and will slid up and over submerged
            Message 5 of 10 , Nov 2, 2002
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              I continue to advocate UHMW for all the reasons sited in this
              thread. With UHMW your boat acts like it has a Teflon shell and will
              slid up and over submerged obstacles like rocks and logs. I'm
              positive if you follow a good building practice with normal bracing
              and bulkheads then plate you boat with this incredible substance you
              will have a three part protection system.

              1. Plywood is stronger than most plain wood when comparing equal
              thickness.

              2. Fiberglass with epoxy provides another excellent layer that will
              allow an impact to be spread over a larger area to absorb the impact
              instead of a puncture.

              3. Finally UHMW is and has been in use on wooden boats for years and
              is becoming a favorite coating for craft exposed to white water or
              rocky beaches where no other bottom protection works like UHMW.

              I implore all boat builders to become acquainted with UHMW, it could
              save your life or hours of cutting and scraping out wood rot. Maybe
              you're afraid of the weight cost but I have used a .22 rifle(in a
              safe area) and if you shoot at UHMW(3/8") directly on it will flatten
              the bullet if the UHMW is backed by plywood. By itself it allows
              penetration but no further travel. Not as effective as kevlar but
              UHMW is supposed to provide a super slick surface that will provide
              something that slides past and over rocks, eliminating punctures.

              I have used UHMW on drift boats that survived my poor navigation
              down some of the most treacherous white water the pacific northwest
              has to offer. The outcome, Rivers 7 oars. Boats, well over 100
              anadromous fish including steelhead, Salmon and Char. Some rapids
              caused impacts that would have literally torn the bottom out of a
              plain plywood with fiberglass covered bottom.

              I cannot make anyone use UHMW but I will use it myself when I know
              the safety of myself, family and other passengers depend on my good
              judgment. UHMW is the greatest innovation for wooden boats since
              bronze screws. The views expressed here are mine alone and do not
              represent Yahoo or others who post on this forum(LOL).

              John





              --- In bolger@y..., "Ned Asplundh" <nasplundh@y...> wrote:
              > Lookee here:
              >
              > http://www.oneoceankayaks.com/Abrasion.htm
              >
              > ...for one builder's take on the "good, bad and ugly" of differing
              > reinforcement fabrics.
              >
              > --- In bolger@y..., David Ryan <david@c...> wrote:
              > > FBBB --
              > >
              > > As you all know, I am a big advocate of glassing over plywood
              > > anywhere the sun beat down on it. Theres's simply no comparison
              > > between how long a prime&paint finish lasts vs. glass/epoxy/paint.
              > >
              > > However, I've had no good experience "glassing for impact
              > resistance"
              > > on my small boats.
              > >
              > > The inevitable result is the glass fails at the point of impact,
              > > allowing water to creep under the glass job. Over time, the
              results
              > > of this are even worse than using no glass at all! Glass
              > delaminates,
              > > trapped water does nasty things to the wood, etc.
              > >
              > > Now that doesn't mean I don't double up around chines, and other
              > > pointy parts of the boat. But I don't expect my "impact
              protection
              > > either." Perhaps on a larger craft you could build up the glass
              > > enough to provide some meaningful protection, but I think on a
              > small,
              > > cheap boat it's both cost and weight prohibitive.
              > >
              > > YIBB,
              > >
              > > David
              > > --
              > >
              > > C.E.P.
              > > 415 W.46th Street
              > > New York, New York 10036
              > > http://www.crumblingempire.com
              > > Mobile (646) 325-8325
              > > Office (212) 247-0296
            • brucehallman
              ... I am intrigued by the stuff. Has PCB expressed an opinion? Beyond the advantages that John mentions, I imagine that barnacles, etc. will not attach to
              Message 6 of 10 , Nov 2, 2002
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                --- In bolger@y..., "John Cupp" <caj@k...> wrote:
                > I continue to advocate UHMW for all the reasons sited in this
                > thread.

                I am intrigued by the stuff. Has PCB
                expressed an opinion? Beyond the
                advantages that John mentions, I
                imagine that barnacles, etc. will
                not attach to it. Similar for
                boring clams. Sort of the modern
                answer to copper cladding.
              • Sakari Aaltonen
                ... But where du you buy it? What form does it come in? How much does it cost? Sakari Aaltonen
                Message 7 of 10 , Nov 2, 2002
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                  > .......... UHMW is the greatest innovation for wooden boats since
                  > bronze screws. The views expressed here are mine alone and do not
                  > represent Yahoo or others who post on this forum(LOL).
                  >
                  > John

                  But where du you buy it? What form does it come in? How much does it cost?


                  Sakari Aaltonen
                • sals_dad
                  ... it cost? ... Try Crown Plastics: http://www.crownplastics.com/ 513-367-0238. For notes on a conversation I had with Pete there, see
                  Message 8 of 10 , Nov 4, 2002
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                    > > .......... UHMW is the greatest innovation for wooden boats since
                    > > bronze screws.
                    >
                    > But where du you buy it? What form does it come in? How much does
                    it cost?
                    >

                    Try Crown Plastics: http://www.crownplastics.com/ 513-367-0238. For
                    notes on a conversation I had with Pete there, see
                    http://groups.yahoo.com/group/bolger/message/23430 . There are lots
                    of other vendors (try a Google search) but Pete seemed knowledgeable.

                    He sent me a couple 10" square samples of adhesive-backed UHMW, but I
                    haven't yet had a boat upside down to apply it. Wonder how it
                    adheres in cold temps?

                    Sal's Dad
                    (still peeved 'cause the Diablo's new Yamaha wouldn't start this
                    weekend - it wasn't THAT cold, just a bit of ice in the bilge...)
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