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ZAMAC

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  • Daniel Osvaldo Caso
    Hi all: Can someone tell me if zamac and white metal are the same thing? I would also appreciate if someone can specify what is actually white metal (it s
    Message 1 of 7 , Apr 2, 2009
      Hi all:

      Can someone tell me if "zamac" and white metal are the same thing?

      I would also appreciate if someone can specify what is actually
      white metal (it's components and eventually proportions)) as used for good castings.

      Thank you.

      Daniel
    • Herb Kephart
      ... Daniel- Zamac is an alloy of zinc, aluminum, magnesium and copper, pressure cast in metal (usually steel) molds, at a much higher temperature (1100F ?)
      Message 2 of 7 , Apr 2, 2009
        --- In FS32NGModelrail@yahoogroups.com, "Daniel Osvaldo Caso" <d.caso@...> wrote:
        >
        > Hi all:
        >
        > Can someone tell me if "zamac" and white metal are the same thing?
        >
        > I would also appreciate if someone can specify what is actually
        > white metal (it's components and eventually proportions)) as used for good castings.
        >
        > Thank you.
        >
        > Daniel
        >
        Daniel- Zamac is an alloy of zinc, aluminum, magnesium and copper, pressure cast in metal (usually steel) molds, at a much higher temperature (1100F ?) than white metal. Even a minute amount of lead in the mix will eventually cause the casting to fall apart do to inter-granular corrosion

        White metal, sometimes erroneously called pewter, is an alloy of tin and varying amounts of lead and bismuth. It can be cast into vulcanized rubber molds, which are spun at a speed to subject the molten metal to about 25 times the force of gravity, to aid in filling the cavities. Usually poured around 525-575 deg F.

        More tin better for thin sections to get fill

        A little more lead for thick pieces, costs less, and can be poured a little cooler, giving longer mold life.

        Bismuth adds stiffness.

        Hope that this helps

        Herb Kephart

        Real Pewter is almost 100% tin
      • David.Halfpenny
        Qualifiers on whitemetals: - a friend is dying slowly from lead poisoning contracted when he had a model kit business. - antique pewter usually contains lead -
        Message 3 of 7 , Apr 2, 2009
          Qualifiers on whitemetals:

          - a friend is dying slowly from lead poisoning contracted when he had a
          model kit business.

          - antique pewter usually contains lead

          - modern pewter contains toxic antimony, but not a lot of it.

          David 1/2d
        • daniel caso
          Herb: Thank you. I see it isn t a simple question and I must learn before stepping into it. Now, if you don t mind, here another questions: 1- What would be
          Message 4 of 7 , Apr 3, 2009
            Herb:

            Thank you. I see it isn't a simple question and I
            must learn before stepping into it.
            Now, if you don't mind, here another questions:

            1- What would be the advantages and disadvantages at
            using zamac for small (and not so small)1/32 scale
            kit parts?

            2- How can I expect -eventually- zamac to react to
            friction if used, for example, for axleboxes where
            the end of pin-point axles are going to pivot into
            conical holes? I have seen this done among other in
            many Wrightlines parts. I have many myself
            (includding a dozen of Roy's wonderful skips) an
            NEVER had problems with them; but don't know if
            I could expect something simmilar from zamac cast
            pieces.

            Thank you again.


            Daniel










            --- Herb Kephart <ebtm3@...> wrote:

            > --- In FS32NGModelrail@yahoogroups.com, "Daniel
            > Osvaldo Caso" <d.caso@...> wrote:
            > >
            > > Hi all:
            > >
            > > Can someone tell me if "zamac" and white metal
            > are the same thing?

            > >
            > > I would also appreciate if someone can specify
            > what is actually
            > > white metal (it's components and eventually
            > proportions)) as used for good castings.
            > >
            > > Thank you.
            > >
            > > Daniel
            > >
            > Daniel- Zamac is an alloy of zinc, aluminum,
            > magnesium and copper, pressure cast in metal
            > (usually steel) molds, at a much higher temperature
            > (1100F ?) than white metal. Even a minute amount of
            > lead in the mix will eventually cause the casting to
            > fall apart do to inter-granular corrosion
            >
            > White metal, sometimes erroneously called pewter, is
            > an alloy of tin and varying amounts of lead and
            > bismuth. It can be cast into vulcanized rubber
            > molds, which are spun at a speed to subject the
            > molten metal to about 25 times the force of gravity,
            > to aid in filling the cavities. Usually poured
            > around 525-575 deg F.
            >
            > More tin better for thin sections to get fill
            >
            > A little more lead for thick pieces, costs less, and
            > can be poured a little cooler, giving longer mold
            > life.
            >
            > Bismuth adds stiffness.
            >
            > Hope that this helps
            >
            > Herb Kephart
            >
            > Real Pewter is almost 100% tin
            >
            >


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          • daniel caso
            David: Thank you. Sad about your friend. I understand very clear your signal. Good to know. But aren t nowadays good methods for dealing with that? Is that
            Message 5 of 7 , Apr 3, 2009
              David:

              Thank you. Sad about your friend. I understand
              very clear your signal. Good to know.
              But aren't nowadays good methods for dealing with
              that?
              Is that related JUST (...) to the production
              process of would it also involve some risks for
              the people building/using the kits?

              Extremely important aspect!

              Thank you.

              Daniel





              --- "David.Halfpenny" <david.halfpenny@...>
              wrote:

              > Qualifiers on whitemetals:
              >
              > - a friend is dying slowly from lead poisoning
              > contracted when he had a
              > model kit business.
              >
              > - antique pewter usually contains lead
              >
              > - modern pewter contains toxic antimony, but not a
              > lot of it.
              >
              > David 1/2d
              >
              >


              Send instant messages to your online friends http://uk.messenger.yahoo.com
            • David.Halfpenny
              ... From: daniel caso Sent: Friday, April 03, 2009 8:13 AM To: Subject: Re: [FS32NGModelrail] Re: ZAMAC
              Message 6 of 7 , Apr 3, 2009
                --------------------------------------------------
                From: "daniel caso" <d.caso@...>
                Sent: Friday, April 03, 2009 8:13 AM
                To: <FS32NGModelrail@yahoogroups.com>
                Subject: Re: [FS32NGModelrail] Re: ZAMAC

                >
                > David:
                >
                > Thank you. Sad about your friend. I understand
                > very clear your signal. Good to know.
                > But aren't nowadays good methods for dealing with
                > that?
                > Is that related JUST (...) to the production
                > process of would it also involve some risks for
                > the people building/using the kits?
                >
                > Extremely important aspect!
                >
                Daniel,

                My friend has been badly affected by breathing heavy metal vapour from
                casting whitemetal alloys for many years.

                Building kits is much less dangerous, but heavy metals accumulate in the
                body and cannot be got rid of. So it is a good idea to wash hands well
                before eating and to keep metal dust out of food drink and air.

                David 1/2d
              • Herb Kephart
                ... Question#1- Zamac is stiffer, harder, and stronger- advantage Disadvantage- cost of making a metal mold- You would probably have to sell thousands of parts
                Message 7 of 7 , Apr 3, 2009
                  --- In FS32NGModelrail@yahoogroups.com, daniel caso <d.caso@...> wrote:
                  >Daniel-
                  Question#1-
                  Zamac is stiffer, harder, and stronger- advantage
                  Disadvantage- cost of making a metal mold- You would probably have to sell thousands of parts just to pay for the mold. Cutting a cavity in a steel mold block with EDM (electric discharge machining) is slow process, and then you would have to get a commercial firm to do the castings- and they might not want to bother unless you ordered a great number of pieces.

                  Zamac was used as a bearing material for needle point axles for years in HO, before the advent of plastic trucks. It was even used as frame material for steam models with the steel driver axles running on the Zamac.

                  While there is a danger handling lead, common sense- washing hands befoer eating- etc., and the fact that you would not be doing it all day every day means to me that the danger of harm is remote.The chance of harm to the customer is even less, so long as they have enough sense not to chew on the parts.

                  Pewter nowdays has other materials added- but in the days that it was used as a material for food preparing the English government decreed by law that it be better than 99% tin- "Crown Pewter". The people that make art objects, and collectable items will call any mixture pewter. Herb
                  >
                  > Herb:
                  >
                  > Thank you. I see it isn't a simple question and I
                  > must learn before stepping into it.
                  > Now, if you don't mind, here another questions:
                  >
                  > 1- What would be the advantages and disadvantages at
                  > using zamac for small (and not so small)1/32 scale
                  > kit parts?
                  >
                  > 2- How can I expect -eventually- zamac to react to
                  > friction if used, for example, for axleboxes where
                  > the end of pin-point axles are going to pivot into
                  > conical holes? I have seen this done among other in
                  > many Wrightlines parts. I have many myself
                  > (includding a dozen of Roy's wonderful skips) an
                  > NEVER had problems with them; but don't know if
                  > I could expect something simmilar from zamac cast
                  > pieces.
                  >
                  > Thank you again.
                  >
                  >
                  > Daniel
                  >
                  >
                  >
                  >
                  >
                  >
                  >
                  >
                  >
                  >
                  > --- Herb Kephart <ebtm3@...> wrote:
                  >
                  > > --- In FS32NGModelrail@yahoogroups.com, "Daniel
                  > > Osvaldo Caso" <d.caso@> wrote:
                  > > >
                  > > > Hi all:
                  > > >
                  > > > Can someone tell me if "zamac" and white metal
                  > > are the same thing?
                  >
                  > > >
                  > > > I would also appreciate if someone can specify
                  > > what is actually
                  > > > white metal (it's components and eventually
                  > > proportions)) as used for good castings.
                  > > >
                  > > > Thank you.
                  > > >
                  > > > Daniel
                  > > >
                  > > Daniel- Zamac is an alloy of zinc, aluminum,
                  > > magnesium and copper, pressure cast in metal
                  > > (usually steel) molds, at a much higher temperature
                  > > (1100F ?) than white metal. Even a minute amount of
                  > > lead in the mix will eventually cause the casting to
                  > > fall apart do to inter-granular corrosion
                  > >
                  > > White metal, sometimes erroneously called pewter, is
                  > > an alloy of tin and varying amounts of lead and
                  > > bismuth. It can be cast into vulcanized rubber
                  > > molds, which are spun at a speed to subject the
                  > > molten metal to about 25 times the force of gravity,
                  > > to aid in filling the cavities. Usually poured
                  > > around 525-575 deg F.
                  > >
                  > > More tin better for thin sections to get fill
                  > >
                  > > A little more lead for thick pieces, costs less, and
                  > > can be poured a little cooler, giving longer mold
                  > > life.
                  > >
                  > > Bismuth adds stiffness.
                  > >
                  > > Hope that this helps
                  > >
                  > > Herb Kephart
                  > >
                  > > Real Pewter is almost 100% tin
                  > >
                  > >
                  >
                  >
                  > Send instant messages to your online friends http://uk.messenger.yahoo.com
                  >
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