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

Re: Concrete keels?

Expand Messages
  • pvanderw@optonline.net
    We can be specific. From William Garden s Yacht Designs, we get Lead - 710 lb/cu ft Iron - 440 lb/cu ft Concrete - 144 lb/cu ft By putting boiler punchings,
    Message 1 of 17 , Dec 1, 2001
      We can be specific.

      From William Garden's Yacht Designs, we get

      Lead - 710 lb/cu ft
      Iron - 440 lb/cu ft
      Concrete - 144 lb/cu ft

      By putting boiler punchings, etc. in the concrete, we can increase
      the weight. Let us guess (I really don't know what is realistic) we
      can get

      Iron/Concrete mix - 250 lb cu ft.

      Now, the first 64 lb in each cu ft compensates for the displaced
      water, so the ballast effect is that much less than the above numbers.

      Lead - 646 lb/cu ft
      Iron - 346 lb/cu ft
      Mix - 186 lb/cu ft
      Concrete - 80 lb/cu ft

      The Micro ballast casting is supposed to be 420 lbs (from Common
      Sense Designs site) or .59 cu ft. and will have 382 lb of ballast
      effect. The equivalent ballast volumes are then:

      Lead - .59 cu ft
      Iron - 1.10 cu ft
      Mix - 2.05 cu ft
      Concrete - 4.78 cu ft.

      You can see that the keel would need complete redesign to use a
      concrete ballast casting.

      PHV
    • amoore@hfx.eastlink.ca
      I must agree with Bill here. There is a reason the old timers use lead most of the time and most of that reason is density. For the price and availability
      Message 2 of 17 , Dec 2, 2001
        I must agree with Bill here. There is a reason the old timers use
        lead most of the time and most of that reason is density. For the
        price and availability you can't get much denser. Switching a micro
        keel to cement you would have to increase you depth quite a bit to get
        the same righting arm. There is another reason to use lead and it
        depends on the ballast location, not being familar with Micro's I
        don't know if this applies. Lead is soft and if external (bolted on
        the bottom of the hull as apposed to poored in the hull) ballast is
        used it can make for a very good shock aborber against an unfortunate
        bump on something hard like a rock. Iron can send a terible vibration
        through the hull affecting the keel bolts, cement could crumble and or
        vibrate the keel bolts(or what ever) which would be very difficult to
        repare. Any dents in lead are easy to repare.


        Andy
      • thomas dalzell
        In micro s case the slug is inserted into a plywood housing, so you couldn t get reasonable stability from cement in the shoe, but you possibly could with a
        Message 3 of 17 , Dec 2, 2001
          In micro's case the slug is inserted into a plywood
          housing, so you couldn't get reasonable stability from
          cement in the shoe, but you possibly could with a full
          length cement keel.

          --- amoore@... wrote:

          <HR>
          <html><body>
          <tt>
          <BR>
          I must agree with Bill here.  There is a reason
          the old timers use<BR>
          lead most of the time and most of that reason is
          density.  For the<BR>
          price and availability you can't get much
          denser.  Switching a micro<BR>
          keel to cement you would have to increase you depth
          quite a bit to get<BR>
          the same righting arm.  There is another reason
          to use lead and it<BR>
          depends on the ballast location, not being familar
          with Micro's I<BR>
          don't know if this applies.  Lead is soft and if
          external (bolted on<BR>
          the bottom of the hull as apposed to poored in the
          hull) ballast is<BR>
          used it can make for a very good shock aborber against
          an unfortunate<BR>
          bump on something hard like a rock.  Iron can
          send a terible vibration<BR>
          through the hull affecting the keel bolts, cement
          could crumble and or<BR>
          vibrate the keel bolts(or what ever) which would be
          very difficult to<BR>
          repare.  Any dents in lead are easy to
          repare.<BR>
          <BR>
          <BR>
          Andy<BR>
          <BR>
          </tt>

          <br>

          <!-- |**|begin egp html banner|**| -->

          <table border=0 cellspacing=0 cellpadding=2>
          <tr bgcolor=#FFFFCC>
          <td align=center><font size="-1"
          color=#003399><b>Yahoo! Groups Sponsor</b></font></td>
          </tr>
          <tr bgcolor=#FFFFFF>
          <td align=center width=470><table border=0
          cellpadding=0 cellspacaaing=0>
          <tr>
          <td align=center><font face=arial
          size=-2>ADVERTISEMENT</font><br><a
          href="http://rd.yahoo.com/M=178320.1681224.3270152.1261774/D=egroupweb/S=1705065791:HM/A=879172/R=0/*http://www.fastweb.com/ib/yahoo-75f"><img
          src="http://us.a1.yimg.com/us.yimg.com/a/fa/fastweb/newred300x250.gif"
          alt="" width="300" height="250" border="0"></a></td>
          </tr>
          </table></td>
          </tr>
          <tr><td><img alt="" width=1 height=1
          src="http://us.adserver.yahoo.com/l?M=178320.1681224.3270152.1261774/D=egroupmail/S=1705065791:HM/A=879172/rand=177583232"></td></tr>
          </table>

          <!-- |**|end egp html banner|**| -->


          <br>
          <tt>
          Bolger rules!!!<BR>
          - no cursing, flaming, trolling, spamming, or flogging
          dead horses<BR>
          - pls take "personals" off-list, stay on
          topic, and punctuate<BR>
          - add your comments at the TOP and SIGN your posts,
          snip all you like<BR>
          - To order plans: Mr. Philip C. Bolger, P.O. Box 1209,
          Gloucester, MA, 01930, Fax: (978) 282-1349<BR>
          - Unsubscribe: 
          bolger-unsubscribe@yahoogroups.com</tt>
          <br>

          <br>
          <tt>Your use of Yahoo! Groups is subject to the <a
          href="http://docs.yahoo.com/info/terms/">Yahoo! Terms
          of Service</a>.</tt>
          </br>

          </body></html>



          _______________________________________________________
          Build your own website in minutes and for free at http://ca.geocities.com
        • John Bell
          Chiming in late here... I suspect this story leaves something out: Could it have been the keelbolts had been removed for some type of repair? But because the
          Message 4 of 17 , Dec 3, 2001
            Chiming in late here...

            I suspect this story leaves something out: Could it have been the keelbolts
            had been removed for some type of repair? But because the keel had been
            bedded in 5200, it did not fall off right away without some persuasion.

            I can't imagine a manufacturer purposely leaving out keelboats. Too much
            liability there. 5200 is good stuff, but it ain't that good.

            JB



            ----- Original Message -----
            From: <mat_man@...>
            To: <bolger@yahoogroups.com>
            Sent: Friday, November 30, 2001 8:57 PM
            Subject: [bolger] Re: Concrete keels?


            | About the only thing I could find at rec.boat.building was
            | from Glenn Ashmore (builder of 45' stip/glass cutter):
            |
            | "I've seen a fin held on only by 5200 my self. To get it off, the
            | boat was raised with a travellift and a fork lift truck was brought
            | is to support the keel as the 5200 was cut off. Even then the fork
            | lift had to work the keel a little to get it off. Overall it was a
            | smooth operation and left me with a very comfortable feeling. There
            | was no possibility that keel would come off by itself even if all the
            | bolts failed.
            |
            | The keel had to come off so the boat could be shipped."
            |
            |
            | Mat
            |
            |
            |
            |
            |
            |
            |
            | Bolger rules!!!
            | - no cursing, flaming, trolling, spamming, or flogging dead horses
            | - pls take "personals" off-list, stay on topic, and punctuate
            | - add your comments at the TOP and SIGN your posts, snip all you like
            | - To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA,
            01930, Fax: (978) 282-1349
            | - Unsubscribe: bolger-unsubscribe@yahoogroups.com
            |
            | Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
            |
            |
          • ravenous@gate.net
            ... JB, You are exactly right. ... BTW, the 316 SS bolts were in perfect shape even after 15 years of blue water cruising. The 5200 kept any possibility of
            Message 5 of 17 , Dec 3, 2001
              "John Bell" <jmbell@m...> wrote:
              >Chiming in late here...
              >I suspect this story leaves something out: Could it have been the
              >keelbolts had been removed for some type of repair? But because the
              >keel had been bedded in 5200, it did not fall off right away without
              >some persuasion.

              JB,
              You are exactly right.
              The rest of Glenn Ashmore's post:
              --------------------
              BTW, the 316 SS bolts were in perfect shape even after 15 years of
              blue water cruising. The 5200 kept any possibility of sea water
              reaching the them. The keel had to come off so the boat could be
              shipped.
              ----------------------------------
              Rhett, the soon to be "Other AF4 Owner in Georgia"
            Your message has been successfully submitted and would be delivered to recipients shortly.