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Re: AF4 Progress and Question

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  • rlspell2000
    I suspect the oak/epoxy joint failures have something to do with the hardness of the oak. You may have a bond that will rip the wood fibers of pine in
    Message 1 of 10 , Apr 4, 2002
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      I suspect the oak/epoxy joint failures have something to do with the
      hardness of the oak. You may have a bond that will rip the wood
      fibers of pine in destructive testing. Test the same joint with oak,
      and the joint fails. It may be because it takes more force to pull
      appart oak than pine. Say, the epoxy joint is stronger than pine but
      not oak.

      I've tested with oak epoxied to ply, and it always broke appart in
      the fibers of the ply. Do your own testing to be sure.
      --- In Michalak@y..., jhkohnen@b... wrote:
      > Congratulations! You've done the hardest part: getting started on
      the
      > project, that's even harder than getting it finished, for me at
      least. <g>
      >
      > "They" say that oak and epoxy are a bad mix, there's apparently
      lots of
      > evidence of joint failures in epoxy glued oak. Something about the
      > chemistry, I guess. You might want to use someother glue, for your
      scarfs
      > at least. The joints between the chines and the bottom and sides are
      > probably going to be backed up with fasteners, right?
      >
      > Good luck with the project.
      >
      > On Wed, 03 Apr 2002 20:40:48 -0000, Pat Pateson wrote:
      > > I actually started Cutting for my AF4 yesterday.
      > > I cut the Chines from a very nice 10' White oak board.
      > > Now, All I have to do is connect the rest of the boat to them.
      > > I also built a simple scarfing jig for my radial arm saw.
      > > 10 to 1 sound about right?
      > > ...
      >
      >
      > --
      > John <jkohnen@b...>
      > http://www.boat-links.com/
      > The way to fight a woman is with your hat. Grab it and run. <John
      Barrymore>
    • antec007
      Thanks for the reply regarding White Oak and Epoxy. John s message got me scarred, (John always scares me)and I have being trying to do some research on
      Message 2 of 10 , Apr 5, 2002
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        Thanks for the reply regarding White Oak and Epoxy.
        John's message got me scarred, (John always scares me)and I have
        being trying to do some research on bonding White Oak with epoxy.
        I'm not absolutely sure I would trust my own testing.

        I have not been able to find any info on "Chemical" causes for the
        failures.
        I have found some warnings about "Physical" causes, particularly the
        necessity to "Roughen" the surface of the oak, to give it some teethe
        for the epoxy to grab.
        Apparently white oak is so hard that a surface that comes off a
        planer, or even a saw, is too smooth and hard for the epoxy to grab.

        I am open to Any info regarding bonding White Oak with epoxy.
        Not to disregard John's concerns and warning, but I think it would be
        a loss to boat builders to Not be Able to use White Oak with Epoxy
        for a fear of joint failure simply because it is "White Oak", when
        the real cause of the failure may be lack of proper "Technique".

        White Oak does have great boat building properties.
        It was a staple of boat building long befor Epoxy
        The cost of white oak has remained fairly constant in the last few
        year, while the cost of VG fir, and lots of other good boat building
        woods has increased a lot. (It is only about half the cost of VG fir.)
        It is Very Strong. It is dense, and holds mechanical fastenings
        extremely well, if you can get the fastenings attached in the first
        place. (Again, technique, not inherent property of White Oak, you
        can't Just drive a nail or screw into it without drilling first.)
        It bends well without breaking. If it is cut in relatively thin
        strips,
        and laminate, it makes for a very strong, curved piece. It apparently
        bends very well when "Steam Bent" (although I have personally never
        tried it.)
        It is also fairly impervious to water, having a closed cell
        structure, even when not "coated".
        (One, one of my favorite things about it, although it has nothing to
        do with it's use in boat building, is that it Smells like an antique
        furniture shop when it is worked. As a furniture builder, I really
        like that. It makes me feel like I am Really building something.)

        Kay talked me out of using "Pigmented Epoxy" instead of paint, since
        it would require some sort of "Painted covering" to protect it
        from "UV" anyway, so I wouldn't be saving any work, and would
        have to be a Lot more careful with the mixing and use of the epoxy to
        get the color we want, and to make sure all the color was the same.
        It's "Latex" again.
        Adding pigment to the epoxy did look like it would be less expensive
        than any paint, if it had a UV protectant in it.
        About $10 worth of pigment will color a gallon of epoxy.


        Thanks all.

        I've cut one piece of wood for my new boat, and already
        "Screwed Up". ( - ;

        Pat

        --- In Michalak@y..., "rlspell2000" <richard@s...> wrote:
        > I suspect the oak/epoxy joint failures have something to do with
        the
        > hardness of the oak. You may have a bond that will rip the wood
        > fibers of pine in destructive testing. Test the same joint with
        oak,
        > and the joint fails. It may be because it takes more force to pull
        > appart oak than pine. Say, the epoxy joint is stronger than pine
        but
        > not oak.
        >
        > I've tested with oak epoxied to ply, and it always broke appart in
        > the fibers of the ply. Do your own testing to be sure.
        > --- In Michalak@y..., jhkohnen@b... wrote:
        > > Congratulations! You've done the hardest part: getting started on
        > the
        > > project, that's even harder than getting it finished, for me at
        > least. <g>
        > >
        > > "They" say that oak and epoxy are a bad mix, there's apparently
        > lots of
        > > evidence of joint failures in epoxy glued oak. Something about the
        > > chemistry, I guess. You might want to use someother glue, for
        your
        > scarfs
        > > at least. The joints between the chines and the bottom and sides
        are
        > > probably going to be backed up with fasteners, right?
        > >
        > > Good luck with the project.
        > >
        > > On Wed, 03 Apr 2002 20:40:48 -0000, Pat Pateson wrote:
        > > > I actually started Cutting for my AF4 yesterday.
        > > > I cut the Chines from a very nice 10' White oak board.
        > > > Now, All I have to do is connect the rest of the boat to them.
        > > > I also built a simple scarfing jig for my radial arm saw.
        > > > 10 to 1 sound about right?
        > > > ...
        > >
        > >
        > > --
        > > John <jkohnen@b...>
        > > http://www.boat-links.com/
        > > The way to fight a woman is with your hat. Grab it and run.
        <John
        > Barrymore>
      • jhkohnen@boat-links.com
        I have that effect on some people. Two things to keep in mind: I only _sound_ like I know what I m talking about (gets me in trouble a lot), and I was only
        Message 3 of 10 , Apr 5, 2002
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          I have that effect on some people. <g> Two things to keep in mind: I only
          _sound_ like I know what I'm talking about (gets me in trouble a lot), and
          I was only parroting what I've picked up in various places from "Them"; the
          collective wisdom of a bunch of boatbuilders who write books and/or post to
          the 'net. You can't always believe what you read in books or see on the
          Web, but there's been an awful lot said about the unsuitability of using
          epoxy with white oak. Where there's smoke? Not necessarily, as we all know,
          but the trouble is that some people have mentioned seeing failures in epoxy
          glued white oak joints years after they were made. How do you test for that
          before building? Was there something wrong with the technique used by the
          people who put those joints together years ago? What's the right technique?

          But then maybe "everybody" knows epoxy and white oak don't go together
          because they've heard it from "everybody" else, but if you asked them they
          don't have any personal experience because they were afraid to try the
          combination. I know that applies to me... <g>

          Take a look in the archives of rec.boats.building:

          http://groups.google.com/groups?hl=en&q=epoxy+oak&btnG=Google+Search&meta=group%3Drec.boats.building

          http://groups.google.com/

          Pat Ford, who restored mahogany motorboats for twenty years, is a
          vociferous opponent of epoxy gluing white oak. He's mentioned seeing failed
          joints years down the road.

          On Fri, 05 Apr 2002 20:58:15 -0000, Pat wrote:
          > Thanks for the reply regarding White Oak and Epoxy.
          > John's message got me scarred, (John always scares me)and I have
          > being trying to do some research on bonding White Oak with epoxy.
          > I'm not absolutely sure I would trust my own testing.
          > ...


          --
          John <jkohnen@...>
          http://www.boat-links.com/
          Why should we take advice on sex from the Pope?
          If he knows anything about it, he shouldn't. <G. B. Shaw>
        • Chuck Leinweber
          Thanks for the info, John. I have had some surprising failures with epoxy too. I once glued some strips of Western Red Cedar to the ply deck of my Caprice.
          Message 4 of 10 , Apr 6, 2002
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            Thanks for the info, John. I have had some surprising failures with epoxy
            too. I once glued some strips of Western Red Cedar to the ply deck of my
            Caprice. I left the upper surface of the unfinished thinking it would make
            a pretty good non-skid surface. It did....until the first time it got wet.
            Those strips popped off that deck faster than you could say Raka. I guess
            everyone but me knows that if wood gets wet AFTER it has been epoxied, the
            glue will let go. That is why they use the term "encapsulation". You have
            to enclose the entire piece of wood. If the wood will get wet, you need to
            use 3M 5200 or Sikaflex on the joint.

            Chuck



            > I have that effect on some people. <g> Two things to keep in mind: I only
            > _sound_ like I know what I'm talking about (gets me in trouble a lot), and
            > I was only parroting what I've picked up in various places from "Them";
            the
            > collective wisdom of a bunch of boatbuilders who write books and/or post
            to
            > the 'net. You can't always believe what you read in books or see on the
            > Web, but there's been an awful lot said about the unsuitability of using
            > epoxy with white oak. Where there's smoke? Not necessarily, as we all
            know,
            > but the trouble is that some people have mentioned seeing failures in
            epoxy
            > glued white oak joints years after they were made. How do you test for
            that
            > before building? Was there something wrong with the technique used by the
            > people who put those joints together years ago? What's the right
            technique?
            >
            > But then maybe "everybody" knows epoxy and white oak don't go together
            > because they've heard it from "everybody" else, but if you asked them they
            > don't have any personal experience because they were afraid to try the
            > combination. I know that applies to me... <g>
            >
            > Take a look in the archives of rec.boats.building:
            >
            >
            http://groups.google.com/groups?hl=en&q=epoxy+oak&btnG=Google+Search&meta=gr
            oup%3Drec.boats.building
            >
            > http://groups.google.com/
            >
            > Pat Ford, who restored mahogany motorboats for twenty years, is a
            > vociferous opponent of epoxy gluing white oak. He's mentioned seeing
            failed
            > joints years down the road.
            >
            > On Fri, 05 Apr 2002 20:58:15 -0000, Pat wrote:
            > > Thanks for the reply regarding White Oak and Epoxy.
            > > John's message got me scarred, (John always scares me)and I have
            > > being trying to do some research on bonding White Oak with epoxy.
            > > I'm not absolutely sure I would trust my own testing.
            > > ...
            >
            >
            > --
            > John <jkohnen@...>
            > http://www.boat-links.com/
            > Why should we take advice on sex from the Pope?
            > If he knows anything about it, he shouldn't. <G. B. Shaw>
            >
            >
            >
            >
            > To unsubscribe from this group, send an email to:
            > Michalak-unsubscribe@yahoogroups.com
            >
            >
            >
            > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
            >
            >
            >
            >
          • rlspell2000
            And, you can t encapsulate with strait epoxy, you need a light cloth to prevent checking.... Why do you think I m using MDO? I ve had some scraps out in the
            Message 5 of 10 , Apr 6, 2002
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              And, you can't encapsulate with strait epoxy, you need a light cloth
              to prevent checking....

              Why do you think I'm using MDO?

              I've had some scraps out in the weather for 9 months, the only pieces
              that even notice the rain are the ones that are thin enough for the
              water to seep in though the edges.

              That resin coated paper is sweet!

              --- In Michalak@y..., "Chuck Leinweber" <chuck@d...> wrote:
              > Thanks for the info, John. I have had some surprising failures
              with epoxy
              > too. I once glued some strips of Western Red Cedar to the ply deck
              of my
              > Caprice. I left the upper surface of the unfinished thinking it
              would make
              > a pretty good non-skid surface. It did....until the first time it
              got wet.
              > Those strips popped off that deck faster than you could say Raka.
              I guess
              > everyone but me knows that if wood gets wet AFTER it has been
              epoxied, the
              > glue will let go. That is why they use the term "encapsulation".
              You have
              > to enclose the entire piece of wood. If the wood will get wet, you
              need to
              > use 3M 5200 or Sikaflex on the joint.
              >
              > Chuck
              >
              >
              >
              > > I have that effect on some people. <g> Two things to keep in
              mind: I only
              > > _sound_ like I know what I'm talking about (gets me in trouble a
              lot), and
              > > I was only parroting what I've picked up in various places
              from "Them";
              > the
              > > collective wisdom of a bunch of boatbuilders who write books
              and/or post
              > to
              > > the 'net. You can't always believe what you read in books or see
              on the
              > > Web, but there's been an awful lot said about the unsuitability
              of using
              > > epoxy with white oak. Where there's smoke? Not necessarily, as we
              all
              > know,
              > > but the trouble is that some people have mentioned seeing
              failures in
              > epoxy
              > > glued white oak joints years after they were made. How do you
              test for
              > that
              > > before building? Was there something wrong with the technique
              used by the
              > > people who put those joints together years ago? What's the right
              > technique?
              > >
              > > But then maybe "everybody" knows epoxy and white oak don't go
              together
              > > because they've heard it from "everybody" else, but if you asked
              them they
              > > don't have any personal experience because they were afraid to
              try the
              > > combination. I know that applies to me... <g>
              > >
              > > Take a look in the archives of rec.boats.building:
              > >
              > >
              > http://groups.google.com/groups?
              hl=en&q=epoxy+oak&btnG=Google+Search&meta=gr
              > oup%3Drec.boats.building
              > >
              > > http://groups.google.com/
              > >
              > > Pat Ford, who restored mahogany motorboats for twenty years, is a
              > > vociferous opponent of epoxy gluing white oak. He's mentioned
              seeing
              > failed
              > > joints years down the road.
              > >
              > > On Fri, 05 Apr 2002 20:58:15 -0000, Pat wrote:
              > > > Thanks for the reply regarding White Oak and Epoxy.
              > > > John's message got me scarred, (John always scares me)and I have
              > > > being trying to do some research on bonding White Oak with
              epoxy.
              > > > I'm not absolutely sure I would trust my own testing.
              > > > ...
              > >
              > >
              > > --
              > > John <jkohnen@b...>
              > > http://www.boat-links.com/
              > > Why should we take advice on sex from the Pope?
              > > If he knows anything about it, he shouldn't. <G. B.
              Shaw>
              > >
              > >
              > >
              > >
              > > To unsubscribe from this group, send an email to:
              > > Michalak-unsubscribe@y...
              > >
              > >
              > >
              > > Your use of Yahoo! Groups is subject to
              http://docs.yahoo.com/info/terms/
              > >
              > >
              > >
              > >
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