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RE: [bolger] Re: Mohegan frindship sloop and ballast

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  • Chester Young
    As a consultant in the marine engineering field doing shoreline revetment work I prefer galvanized grade 60 rebar to epoxy coated. 1st issue is that concrete
    Message 1 of 23 , Feb 1, 2011
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      As a consultant in the marine engineering field doing shoreline revetment work I prefer galvanized grade 60 rebar to epoxy coated.  1st issue is that concrete does not adhere to the epoxy coating.  Any chip in the coating is a vector for rust along the rebar, and when it does fail it tends to do so in large sections.  Observation after failure has shown where long sections of rebar would separate from the concrete due to the epoxy surface being smooth.  Fortunately there is not a lot of epoxy coated steel used in the private sector, bridges are a complete other animal with extensive installation procedures to eliminate penetration through the epoxy.

       

      Just my 2 cents worth, for what it is worth.

       

      Caloosarat

       

      From: bolger@yahoogroups.com [mailto:bolger@yahoogroups.com] On Behalf Of Eric Kramp
      Sent: Monday, January 31, 2011 9:45 PM
      To: bolger@yahoogroups.com
      Subject: [bolger] Re: Mohegan frindship sloop and ballast

       

       

      First time responding. In regards to concrete encased on concrete, it's
      important to remember that the concrete is protecting the steel while
      the steel is providing tensional strength. Concrete in water makes a
      basic solution, and steel tends to rust in an acidic.

      I've chipped away concrete from 50 year old rebar and the steel looked
      quite good. Large cracks, on the other hand, will defeat this combination.

      If I were in a position to build a boat of this size right now, I'd
      research epoxy-coated resteel. Bridge resteel is pretty inexpensive
      compared to bare steel, and would provide a low-oxygen environment for
      the steel.

      -Eric

      From Peter:

      >
      > It's not just concrete. It's concrete with embedded iron or steel
      > scrap. If the metal starts to rust, you are going to have a big mess,
      > so it's necessary to be sure the metal is entirely encapsulated.

    • BruceHallman
      ... Remember here, this is ballast, and the steel is there to provide density to the concrete. Loss of adhesion and the resultant loss of tensile strength is
      Message 2 of 23 , Feb 1, 2011
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        Erik wrote:
        >the steel while the steel is providing tensional strength.
        Chester wrote:
        >1st issue is that concrete does not adhere to the epoxy coating.

        Remember here, this is ballast, and the steel is there to provide
        density to the concrete. Loss of adhesion and the resultant loss of
        tensile strength is of no matter.

        Economy is the issue I think, and high density concrete is the goal as
        being cheap and easy to conform to the irregular shape being filled.
        The more dense the mix, the greater the headroom possible in that tiny
        cabin. I have seen the use of iron ore as aggregate in concrete mixes
        for high density, and also steel punchings are used in marine ballast
        concrete mixes.

        http://www.marineballast.com/steel.html

        http://www.marineballast.com/densities.html
      • daschultz2000
        George Buehler s Backyard Boat Building contains much information about concrete/steel ballast. Buehler is big on very practical construction of useable
        Message 3 of 23 , Feb 1, 2011
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          George Buehler's "Backyard Boat Building" contains much information about concrete/steel ballast. Buehler is big on very practical construction of useable boats. They may not be 'goldplaters' but they get the job done.

          Don
        • BruceHallman
          ... After I hit send to that last email, it occurred to me that using recycled automobile tire lead wheel weights at aggregate would be a real and cheap
          Message 4 of 23 , Feb 1, 2011
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            > for high density, and also steel punchings are used in marine ballast
            > concrete mixes.

            After I hit send to that last email, it occurred to me that using
            recycled automobile tire lead wheel weights at aggregate would be a
            real and cheap alternative. Where I live, you can go down to the
            local tire shops and they all have 5 gallon buckets where they collect
            the wheel weights they discard when they balance new tires on rims.
            The give these away for free or for cheap mostly to the people who
            make lead castings for bullets, or for fishing weights etc.. Put
            these lead wheel weights in the hold of Monhegan, and fill the
            interstitial spaces with cement slurry, and you would get a cheap high
            density ballast.
          • vscopeland
            Great post. Thanks for that practical knowledge.
            Message 5 of 23 , Feb 1, 2011
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              Great post. Thanks for that practical knowledge.

              --- In bolger@yahoogroups.com, "Chester Young" <chester@...> wrote:
              >
              > As a consultant in the marine engineering field doing shoreline
              > revetment work I prefer galvanized grade 60 rebar to epoxy coated. 1st
              > issue is that concrete does not adhere to the epoxy coating. Any chip
              > in the coating is a vector for rust along the rebar, and when it does
              > fail it tends to do so in large sections. Observation after failure has
              > shown where long sections of rebar would separate from the concrete due
              > to the epoxy surface being smooth. Fortunately there is not a lot of
              > epoxy coated steel used in the private sector, bridges are a complete
              > other animal with extensive installation procedures to eliminate
              > penetration through the epoxy.
              >
              >
              >
              > Just my 2 cents worth, for what it is worth.
              >
              >
              >
              > Caloosarat
              >
              >
              >
              > From: bolger@yahoogroups.com [mailto:bolger@yahoogroups.com] On Behalf
              > Of Eric Kramp
              > Sent: Monday, January 31, 2011 9:45 PM
              > To: bolger@yahoogroups.com
              > Subject: [bolger] Re: Mohegan frindship sloop and ballast
              >
              >
              >
              >
              >
              > First time responding. In regards to concrete encased on concrete, it's
              > important to remember that the concrete is protecting the steel while
              > the steel is providing tensional strength. Concrete in water makes a
              > basic solution, and steel tends to rust in an acidic.
              >
              > I've chipped away concrete from 50 year old rebar and the steel looked
              > quite good. Large cracks, on the other hand, will defeat this
              > combination.
              >
              > If I were in a position to build a boat of this size right now, I'd
              > research epoxy-coated resteel. Bridge resteel is pretty inexpensive
              > compared to bare steel, and would provide a low-oxygen environment for
              > the steel.
              >
              > -Eric
              >
              > From Peter:
              > >
              > > It's not just concrete. It's concrete with embedded iron or steel
              > > scrap. If the metal starts to rust, you are going to have a big mess,
              > > so it's necessary to be sure the metal is entirely encapsulated.
              >
            • vscopeland
              Yes, I would do the same, although it negates my eco-friendly notions previously mentioned!
              Message 6 of 23 , Feb 1, 2011
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                Yes, I would do the same, although it negates my eco-friendly notions previously mentioned!

                --- In bolger@yahoogroups.com, BruceHallman <hallman@...> wrote:
                >
                > > for high density, and also steel punchings are used in marine ballast
                > > concrete mixes.
                >
                > After I hit send to that last email, it occurred to me that using
                > recycled automobile tire lead wheel weights at aggregate would be a
                > real and cheap alternative. Where I live, you can go down to the
                > local tire shops and they all have 5 gallon buckets where they collect
                > the wheel weights they discard when they balance new tires on rims.
                > The give these away for free or for cheap mostly to the people who
                > make lead castings for bullets, or for fishing weights etc.. Put
                > these lead wheel weights in the hold of Monhegan, and fill the
                > interstitial spaces with cement slurry, and you would get a cheap high
                > density ballast.
                >
              • Amilcar Rossi
                My experience with iron/concrete ballast is that moist from condensation or incidental rain tend to go between ballast and wood and stay there, creating
                Message 7 of 23 , Feb 2, 2011
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                  My experience with iron/concrete ballast is that moist from condensation or incidental rain tend to go between ballast and wood and stay there, creating problems much earlier than rust

                  Somewhere someone writhed that " never leave inaccessible places in a wooden boat"

                  If the ballast bulks are removable, you can check,   keep dry, or fix some soft spot in the hull

                   

                  Amilcar

                   

                • Peter
                  ... I did wonder about combining carvel construction (fairly flexible) with concrete ballast (monumentally inflexible). Bolger called for about 700lbs of
                  Message 8 of 23 , Feb 2, 2011
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                    > My experience with iron/concrete ballast is that moist
                    > from condensation or incidental rain tend to go between
                    > ballast and wood and stay there, creating problems much
                    > earlier than rust

                    I did wonder about combining carvel construction (fairly flexible) with concrete ballast (monumentally inflexible).

                    Bolger called for about 700lbs of ballast which is about a cubic foot of lead. If the lead were cast in trapezoidal prisms, they might fit comfortbly in the bilge, short side down. It might multiply the work if you have to build several different molds, but you might be able of find a single section yielding say, 4 ingots in the 175lb range that would fit, appropriately shimmed.
                  • vscopeland
                    That s a good idea, and a clean installation, although molding and pouring lead is not easy or cheap, or fast, besides the gases and danger of molten metal if
                    Message 9 of 23 , Feb 2, 2011
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                      That's a good idea, and a clean installation, although molding and pouring lead is not easy or cheap, or fast, besides the gases and danger of molten metal if the mold(s) leak - for an amateur at least. I suppose for pouring concrete one needs a mixer, but that could be borrowed...

                      --- In bolger@yahoogroups.com, "Peter" <pvanderwaart@...> wrote:
                      >
                      >
                      > > My experience with iron/concrete ballast is that moist
                      > > from condensation or incidental rain tend to go between
                      > > ballast and wood and stay there, creating problems much
                      > > earlier than rust
                      >
                      > I did wonder about combining carvel construction (fairly flexible) with concrete ballast (monumentally inflexible).
                      >
                      > Bolger called for about 700lbs of ballast which is about a cubic foot of lead. If the lead were cast in trapezoidal prisms, they might fit comfortbly in the bilge, short side down. It might multiply the work if you have to build several different molds, but you might be able of find a single section yielding say, 4 ingots in the 175lb range that would fit, appropriately shimmed.
                      >
                    • Susanne@comcast.net
                      In general, might it be plausible (?) 1. - to use left-overs of the FIRESTONE rubber-roofing - raid the roofer s dumpster - and a modest batch of vulcanizing
                      Message 10 of 23 , Feb 2, 2011
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                        In general, might it be plausible  (?)
                        1. - to use left-overs of the FIRESTONE rubber-roofing - raid the roofer's dumpster - and a modest batch of vulcanizing adhesive,
                        2. - to cut out and glue up a series of more or less custom fit dedicated shapes/mouldsbetween, say, floor-timbers,
                        3. - to pour the concrete/metal-scraps mix into to pre-determined height,
                        4. - locate one or two j-hooked lengths of threaded galv./SS rod in the curing mix and let set up. 
                        5. - Then screw on threaded eye(s) and lift up that cured ballast segment,
                        6. - peel off/out the rubber 'glove' and reinsert the ballast segment
                        7. - and bolt it down with a metal or wooden bar for reliable duty as ballast. 
                        Annually, lifting up each segment would allow inspection of wood structure and periodic application of anti-rot chemicals that can live with concrete.  That rubber-roofing is very touch and can easily withstand pouring a few hundred pounds of conrete/ballast mix into it surrounded by hull-structure.

                        Susanne Altenburger, PB&F 
                             
                        ----- Original Message -----
                        Sent: Wednesday, February 02, 2011 5:58 PM
                        Subject: [bolger] Re: Mohegan frindship sloop and ballast

                         

                        That's a good idea, and a clean installation, although molding and pouring lead is not easy or cheap, or fast, besides the gases and danger of molten metal if the mold(s) leak - for an amateur at least. I suppose for pouring concrete one needs a mixer, but that could be borrowed...

                        --- In bolger@yahoogroups.com, "Peter" <pvanderwaart@...> wrote:
                        >
                        >
                        > > My experience with iron/concrete ballast is that moist
                        > > from condensation or incidental rain tend to go between
                        > > ballast and wood and stay there, creating problems much
                        > > earlier than rust
                        >
                        > I did wonder about combining carvel construction (fairly flexible) with concrete ballast (monumentally inflexible).
                        >
                        > Bolger called for about 700lbs of ballast which is about a cubic foot of lead. If the lead were cast in trapezoidal prisms, they might fit comfortbly in the bilge, short side down. It might multiply the work if you have to build several different molds, but you might be able of find a single section yielding say, 4 ingots in the 175lb range that would fit, appropriately shimmed.
                        >

                      • david_shurr
                        I just checked the price of lead. A little over $2/lbs w/free shipping. Makes a boat s cost go up. I ll just add a hiking board and have my friends sit on it
                        Message 11 of 23 , Feb 2, 2011
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                          I just checked the price of lead. A little over $2/lbs w/free shipping. Makes a boat's cost go up. I'll just add a hiking board and have my friends sit on it out over the water.

                          Here is just one of the many websites out there.

                          http://www.rotometals.com/Lead-Ingots-s/32.htm

                          David
                        • Peter
                          ... Hence the scrounging at tire stores.... When the tire stores sell the lead, they are selling at source or wholesale prices. Your $2/lb is retail. It pays
                          Message 12 of 23 , Feb 3, 2011
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                            > I just checked the price of lead.
                            > A little over $2/lbs w/free shipping.

                            Hence the scrounging at tire stores....

                            When the tire stores sell the lead, they are selling at source or wholesale prices. Your $2/lb is retail. It pays to cut out the middleman if you can.
                          • etap28
                            Retail lead is high. Most of the boatbuilders I ve ever known scrounge for lead rather than pay retail. The best place to get lead by far is off an old hulk
                            Message 13 of 23 , Feb 3, 2011
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                              Retail lead is high. Most of the boatbuilders I've ever known scrounge for lead rather than pay retail. The best place to get lead by far is off an old hulk rotting in a field. Otherwise, metal salvage yards always have a lot, and it's quite a bit less than retail. And, if you're shipping the lead, than it stand to reason a big chunk of that cost is the shipping. . . Look locally




                              --- In bolger@yahoogroups.com, "david_shurr" <david_shurr@...> wrote:
                              >
                              > I just checked the price of lead. A little over $2/lbs w/free shipping. Makes a boat's cost go up. I'll just add a hiking board and have my friends sit on it out over the water.
                              >
                              > Here is just one of the many websites out there.
                              >
                              > http://www.rotometals.com/Lead-Ingots-s/32.htm
                              >
                              > David
                              >
                            • meier.denis
                              I placed a lead wanted ad on kijiji and had a reply from a retired printer who sold me 450 pounds for 40cents/pound. There is lots of old lead type out
                              Message 14 of 23 , Feb 3, 2011
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                                I placed a "lead wanted" ad on kijiji and had a reply from a retired printer who sold me 450 pounds for 40cents/pound. There is lots of old lead type out there. Worth a try.
                                Denis Meier
                                MicroWave (will launch this year for sure)


                                --- In bolger@yahoogroups.com, "david_shurr" <david_shurr@...> wrote:
                                >
                                > I just checked the price of lead. A little over $2/lbs w/free shipping. Makes a boat's cost go up. I'll just add a hiking board and have my friends sit on it out over the water.
                                >
                                > Here is just one of the many websites out there.
                                >
                                > http://www.rotometals.com/Lead-Ingots-s/32.htm
                                >
                                > David
                                >
                              • Michael Kline
                                Suggest you build closed boxes to fit in the sections and then fill them with used wheel weights. Adjust the weight in each box by adding clean (washed)
                                Message 15 of 23 , Feb 3, 2011
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                                  Suggest you build closed boxes to fit in the sections and then fill them with used wheel weights.  Adjust the weight in each box by adding clean (washed) gravel as needed.  The weights can be acquired from local garages and tire stores and as long as you pay a slight premium over their usual return value, they should be motivated to deal.  This is cheapest place to tap this material stream than anywhere else in the material recovery chain.  The wooden exterior of the boxes should pose no problem for fastening down and could be built with external spacers to promote water and air flow around the boxes.
                                   
                                  Mike
                                   
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