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Questions after my first pour.

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  • raferjl
    Greetings sandcrabs, Having built a furnace, burner, tools, and everything else, I did my first aluminum pour yesterday. I had fair success with my limited
    Message 1 of 19 , Jul 29 1:43 PM
      Greetings sandcrabs,

      Having built a furnace, burner, tools, and everything else, I did my first aluminum pour yesterday. I had fair success with my limited goals.

      However, the experience did bring up some questions.

      First some background. The aluminum source was painted aluminum window frame extrusions. I know this is not ideal, but we had plenty of it. The crucible is welded steel. The goal was to cast several cylindrical shapes for machinability tests. We used broomstick handles stuck into an open faced greensand mold.

      The furnace and burner worked well. The thin extrusions were melting as fast as I could push them down into the puddle. We fluxed with kosher salt, skimmed, degassed with pool shock, skimmed, then poured.

      Of course, the thin extrusions created a lot of dross, but after skimming, we had a crucible of nice shiny aluminum.

      Pouring went well with some awkwardness due to using the tools for the first time.

      There were two issues that I have questions about.

      1) Portions of the melt that were exposed to the air had a sandpapery texture. Not pebbled, or wrinkled, but actually very rough like 120 grit sandpaper. I had expected a smoother surface, perhaps wrinkled by contraction. Is this a normal crystalisation effect for all alloys, or just the crummy extrusion alloy we used, or something else altogether?

      2) The greensand batch that we made would not be at all suitable for a two part mold. Though it would clump together when squeezed in the hand, and broke cleanly, it had no strength to it. We used about 30 percent by volume fire clay (left over from making the furnaces), mixed with 90 grit silica sand. Mixing was done by pushing it around in a wheel barrow until it looked homogeneous. We did not mull or tread on it. We only made about 30 of 40 pounds. Is it possible to make an adequate greensand with just fire clay, sand, and water? Our planned next experiment is to add more and more clay, treading on the sand after each addition, then testing for consistency each time until we think the sand is either strong enough, or no longer has the required porosity. Or should we just give up on fire clay and go with bentonite, or a combination of the two.

      Thanks in advance for reading this long post, and sharing your wisdom.
    • Scott Trostel
      Perhaps you might have had a bit of contamination in your metal that you got a gritty surface.  I use some coated aluminum in some of my melts but its rough
      Message 2 of 19 , Jul 29 2:42 PM
        Perhaps you might have had a bit of contamination in your metal that you got a gritty surface.  I use some coated aluminum in some of my melts but its rough stuff to try and cast so I add some zinc, it flows better and the surface is much more smooth.
        The fire clay will work, I use it but I screen out all the brick chips and crap that they tend to mix into it.  Your percentage is way too high.  I suggest less clay.  I shovel mix my green sand, the goal being just to coat the grains of sand, not to smother them.  Kind of sand also makes a difference.  I've used white sandbox sand, which works, but my favorite is some sand I found along a local river, it is finer and tends to be rougher thus wants to lock together.

        Scott


        [Non-text portions of this message have been removed]
      • David Patterson
        Sounds like your problems are in the sand you used. Extrusions will cast just fine without adding anything to it, it s probably 6061t6 alloy. To make it
        Message 3 of 19 , Jul 29 9:49 PM
          Sounds like your problems are in the sand you used. Extrusions will cast just fine without adding anything to it, it's probably 6061t6 alloy. To make it machine better remove from the mold while still hot, then quench with cold water. Either spray or adgatate in a bucket until it stops steaming.
          Surface finish will depend on how coarse the sand is and the quality of the sand. If you had little green strength, the sand will wash as the metal flows over the mold.
          Every casting I've made so far has been extrusions. Saving the wheels and automotive casting for later. 

          Dave Patterson
          odd_kins@...
          http://home.comcast.net/~oddkins/foundry_home.html

          --- On Fri, 7/29/11, raferjl <jim@...> wrote:


          From: raferjl <jim@...>
          Subject: [hobbicast] Questions after my first pour.
          To: hobbicast@yahoogroups.com
          Date: Friday, July 29, 2011, 1:43 PM


           



          Greetings sandcrabs,

          Having built a furnace, burner, tools, and everything else, I did my first aluminum pour yesterday. I had fair success with my limited goals.

          However, the experience did bring up some questions.

          First some background. The aluminum source was painted aluminum window frame extrusions. I know this is not ideal, but we had plenty of it. The crucible is welded steel. The goal was to cast several cylindrical shapes for machinability tests. We used broomstick handles stuck into an open faced greensand mold.

          The furnace and burner worked well. The thin extrusions were melting as fast as I could push them down into the puddle. We fluxed with kosher salt, skimmed, degassed with pool shock, skimmed, then poured.

          Of course, the thin extrusions created a lot of dross, but after skimming, we had a crucible of nice shiny aluminum.

          Pouring went well with some awkwardness due to using the tools for the first time.

          There were two issues that I have questions about.

          1) Portions of the melt that were exposed to the air had a sandpapery texture. Not pebbled, or wrinkled, but actually very rough like 120 grit sandpaper. I had expected a smoother surface, perhaps wrinkled by contraction. Is this a normal crystalisation effect for all alloys, or just the crummy extrusion alloy we used, or something else altogether?

          2) The greensand batch that we made would not be at all suitable for a two part mold. Though it would clump together when squeezed in the hand, and broke cleanly, it had no strength to it. We used about 30 percent by volume fire clay (left over from making the furnaces), mixed with 90 grit silica sand. Mixing was done by pushing it around in a wheel barrow until it looked homogeneous. We did not mull or tread on it. We only made about 30 of 40 pounds. Is it possible to make an adequate greensand with just fire clay, sand, and water? Our planned next experiment is to add more and more clay, treading on the sand after each addition, then testing for consistency each time until we think the sand is either strong enough, or no longer has the required porosity. Or should we just give up on fire clay and go with bentonite, or a combination of the two.

          Thanks in advance for reading this long post, and sharing your wisdom.








          [Non-text portions of this message have been removed]
        • Jeshua Lacock
          ... Add about 5% copper then it is actually pretty ideal. It will make higher quality and strength castings and will flow much better. Best, Jeshua Lacock,
          Message 4 of 19 , Jul 29 9:54 PM
            On Jul 29, 2011, at 2:43 PM, raferjl wrote:

            > First some background. The aluminum source was painted aluminum window frame extrusions. I know this is not ideal, but we had plenty of it. The crucible is welded steel. The goal was to cast several cylindrical shapes for machinability tests. We used broomstick handles stuck into an open faced greensand mold.

            Add about 5% copper then it is actually pretty ideal.

            It will make higher quality and strength castings and will flow much better.


            Best,

            Jeshua Lacock, Owner
            <http://OpenOSX.com>
            phone: 208.462.4171
          • Rupert
            Hello Raferjl, ... I m doing that now melting down an old obsolete satellite receiver dish. Good idea to stay up wind from any fumes that might be produced
            Message 5 of 19 , Jul 30 5:19 AM
              Hello Raferjl,

              On 7/29/2011 2:43 PM, raferjl wrote:
              >
              > First some background. The aluminum source was painted aluminum
              > window frame extrusions. I know this is not ideal, but we had plenty
              > of it. The crucible is welded steel. The goal was to cast several
              > cylindrical shapes for machinability tests. We used broomstick
              > handles stuck into an open faced greensand mold.

              I'm doing that now melting down an old obsolete satellite receiver
              dish. Good idea to stay up wind from any fumes that might be produced
              from the burning paint.
              Adding 5-8% copper by weight to the melt in the later stage of melting
              will help improve the machinability. Try to find copper wire or small
              pieces to add to the molten aluminum as the molten aluminum will absorb
              the copper. As mentioned, so will quenching the casting while it is
              still hot.
              >
              > The furnace and burner worked well. The thin extrusions were melting
              > as fast as I could push them down into the puddle. We fluxed with
              > kosher salt, skimmed, degassed with pool shock, skimmed, then
              > poured.
              Many of those powders are hydroscopic so just be sure to preheat any
              powders before you plunge them into the melt.

              >
              > Of course, the thin extrusions created a lot of dross, but after
              > skimming, we had a crucible of nice shiny aluminum.
              A lot of dross is normal when melting painted or dirty metal.

              >
              > Pouring went well with some awkwardness due to using the tools for
              > the first time.

              A dry run with a cold crucible is always a good idea even if you do it
              mentally at the beginning of every melt.

              >
              > There were two issues that I have questions about.
              >
              > 1) Portions of the melt that were exposed to the air had a sandpapery
              > texture. Not pebbled, or wrinkled, but actually very rough like 120
              > grit sandpaper. I had expected a smoother surface, perhaps wrinkled
              > by contraction. Is this a normal crystalisation effect for all
              > alloys, or just the crummy extrusion alloy we used, or something else
              > altogether?

              That is normal.
              >
              > 2) The greensand batch that we made would not be at all suitable for
              > a two part mold. Though it would clump together when squeezed in the
              > hand, and broke cleanly, it had no strength to it. We used about 30
              > percent by volume fire clay (left over from making the furnaces),
              > mixed with 90 grit silica sand. Mixing was done by pushing it around
              > in a wheel barrow until it looked homogeneous. We did not mull or
              > tread on it. We only made about 30 of 40 pounds. Is it possible to
              > make an adequate greensand with just fire clay, sand, and water? Our
              > planned next experiment is to add more and more clay, treading on the
              > sand after each addition, then testing for consistency each time
              > until we think the sand is either strong enough, or no longer has the
              > required porosity. Or should we just give up on fire clay and go
              > with bentonite, or a combination of the two.

              My thoughts on this one are way too much fireclay. Use bentonite as the
              binder as mentioned in another post. The 90 grit sand will work but the
              texture of the casting will be coarse.

              Rupert


              --

              yvt

              Rupert Wenig
              Camrose, Alberta, Canada.

              email: rwenig2@...

              http://users.xplornet.com/~rwenig/Home/
            • raferjl
              Thank you to everyone for your replies. I ve redesigned my liftout and pouring shanks to be two separate tools. I m using a similar pouring shank to the ones
              Message 6 of 19 , Aug 3, 2011
                Thank you to everyone for your replies.

                I've redesigned my liftout and pouring shanks to be two separate tools. I'm using a similar pouring shank to the ones you see in myfordboy's youtube videos. These have been dry run tested without scary hot molten metal.

                We're buying some bentonite clay to make a new batch of green sand.
                We'll probably mix it, and let it season for a day before use.

                A couple of responders have suggested using zinc or copper to help with free-flowing pours and machinability of the nearly-pure aluminum from extrusions.

                What do you think about using newer pennies as a source of zinc (plus a little copper)? What are some other sources of scrap zinc?

                Also, what does the group think of using aluminum turning chips as a source of scrap aluminum? I have a barrel full of mostly 6061 that is relatively oil free, that I could compact into bricks to charge the crucible. They would probably create lots of oxide dross, but otherwise ok?

                --- In hobbicast@yahoogroups.com, Rupert <rwenig2@...> wrote:
                >
                > Hello Raferjl,
                >
                > On 7/29/2011 2:43 PM, raferjl wrote:
                > >
                > > First some background. The aluminum source was painted aluminum
                > > window frame extrusions. I know this is not ideal, but we had plenty
                > > of it. The crucible is welded steel. The goal was to cast several
                > > cylindrical shapes for machinability tests. We used broomstick
                > > handles stuck into an open faced greensand mold.
                >
                > I'm doing that now melting down an old obsolete satellite receiver
                > dish. Good idea to stay up wind from any fumes that might be produced
                > from the burning paint.
                > Adding 5-8% copper by weight to the melt in the later stage of melting
                > will help improve the machinability. Try to find copper wire or small
                > pieces to add to the molten aluminum as the molten aluminum will absorb
                > the copper. As mentioned, so will quenching the casting while it is
                > still hot.
                > >
                > > The furnace and burner worked well. The thin extrusions were melting
                > > as fast as I could push them down into the puddle. We fluxed with
                > > kosher salt, skimmed, degassed with pool shock, skimmed, then
                > > poured.
                > Many of those powders are hydroscopic so just be sure to preheat any
                > powders before you plunge them into the melt.
                >
                > >
                > > Of course, the thin extrusions created a lot of dross, but after
                > > skimming, we had a crucible of nice shiny aluminum.
                > A lot of dross is normal when melting painted or dirty metal.
                >
                > >
                > > Pouring went well with some awkwardness due to using the tools for
                > > the first time.
                >
                > A dry run with a cold crucible is always a good idea even if you do it
                > mentally at the beginning of every melt.
                >
                > >
                > > There were two issues that I have questions about.
                > >
                > > 1) Portions of the melt that were exposed to the air had a sandpapery
                > > texture. Not pebbled, or wrinkled, but actually very rough like 120
                > > grit sandpaper. I had expected a smoother surface, perhaps wrinkled
                > > by contraction. Is this a normal crystalisation effect for all
                > > alloys, or just the crummy extrusion alloy we used, or something else
                > > altogether?
                >
                > That is normal.
                > >
                > > 2) The greensand batch that we made would not be at all suitable for
                > > a two part mold. Though it would clump together when squeezed in the
                > > hand, and broke cleanly, it had no strength to it. We used about 30
                > > percent by volume fire clay (left over from making the furnaces),
                > > mixed with 90 grit silica sand. Mixing was done by pushing it around
                > > in a wheel barrow until it looked homogeneous. We did not mull or
                > > tread on it. We only made about 30 of 40 pounds. Is it possible to
                > > make an adequate greensand with just fire clay, sand, and water? Our
                > > planned next experiment is to add more and more clay, treading on the
                > > sand after each addition, then testing for consistency each time
                > > until we think the sand is either strong enough, or no longer has the
                > > required porosity. Or should we just give up on fire clay and go
                > > with bentonite, or a combination of the two.
                >
                > My thoughts on this one are way too much fireclay. Use bentonite as the
                > binder as mentioned in another post. The 90 grit sand will work but the
                > texture of the casting will be coarse.
                >
                > Rupert
                >
                >
                > --
                >
                > yvt
                >
                > Rupert Wenig
                > Camrose, Alberta, Canada.
                >
                > email: rwenig2@...
                >
                > http://users.xplornet.com/~rwenig/Home/
                >
              • Jarod Eells
                You might try the chips a time or two and see how much metal you recover. Then you can decide if it is worth it for you. Others have reported that it was too
                Message 7 of 19 , Aug 3, 2011
                  You might try the chips a time or two and see how much metal you recover.
                  Then you can decide if it is worth it for you. Others have reported that
                  it was too much work for what they got back. I did this once with a whole
                  bucket of Al punch-outs that someone gave me but those had more volume than typical chips.
                  It's the amount of surface area that is exposed to oxygen and creates dross.

                  Jarod.

                  On Wed, Aug 03, 2011 at 09:32:07PM -0000, raferjl wrote:
                  > Thank you to everyone for your replies.
                  >
                  > I've redesigned my liftout and pouring shanks to be two separate tools. I'm using a similar pouring shank to the ones you see in myfordboy's youtube videos. These have been dry run tested without scary hot molten metal.
                  >
                  > We're buying some bentonite clay to make a new batch of green sand.
                  > We'll probably mix it, and let it season for a day before use.
                  >
                  > A couple of responders have suggested using zinc or copper to help with free-flowing pours and machinability of the nearly-pure aluminum from extrusions.
                  >
                  > What do you think about using newer pennies as a source of zinc (plus a little copper)? What are some other sources of scrap zinc?
                  >
                  > Also, what does the group think of using aluminum turning chips as a source of scrap aluminum? I have a barrel full of mostly 6061 that is relatively oil free, that I could compact into bricks to charge the crucible. They would probably create lots of oxide dross, but otherwise ok?
                  >
                • Evan Daniel
                  ... You ll find the bentonite to be a big improvement. It s also worth getting finer sand if you can find it locally. Where are you located? I ve found chips
                  Message 8 of 19 , Aug 3, 2011
                    On Wed, Aug 3, 2011 at 5:32 PM, raferjl <jim@...> wrote:
                    > Thank you to everyone for your replies.
                    >
                    > I've redesigned my liftout and pouring shanks to be two separate tools.  I'm using a similar pouring shank to the ones you see in myfordboy's youtube videos.  These have been dry run tested without scary hot molten metal.
                    >
                    > We're buying some bentonite clay to make a new batch of green sand.
                    > We'll probably mix it, and let it season for a day before use.
                    >
                    > A couple of responders have suggested using zinc or copper to help with free-flowing pours and machinability of the nearly-pure aluminum from extrusions.
                    >
                    > What do you think about using newer pennies as a source of zinc (plus a little copper)?  What are some other sources of scrap zinc?
                    >
                    > Also, what does the group think of using aluminum turning chips as a source of scrap aluminum?  I have a barrel full of mostly 6061 that is relatively oil free, that I could compact into bricks to charge the crucible.  They would probably create lots of oxide dross, but otherwise ok?

                    You'll find the bentonite to be a big improvement. It's also worth
                    getting finer sand if you can find it locally. Where are you located?

                    I've found chips and turnings to be more trouble than they're worth,
                    but mine have been slightly oily and not compressed.

                    Pennies would work fine as a source of zinc (97.5 % Zn, 2.5% Cu),
                    except that they're illegal to use for such purposes. As of late last
                    year (iirc) melting down pennies or nickels for their metallurgical
                    contents is prohibited. (The market value of the metals exceeds the
                    face value of the coins.)

                    Evan Daniel
                  • Scott Trostel
                    There are lots of sources for scrap zinc.  My favorite is three local plastic plants that get their pellets in railroad cars.  The discharge caps on the
                    Message 9 of 19 , Aug 3, 2011
                      There are lots of sources for scrap zinc.  My favorite is three local plastic plants that get their pellets in railroad cars.  The discharge caps on the bottom of the cars are sealed with a steel wire and the locking bond is a chunk of zinc. They cut the wire and toss the seals to the side of the track as the cars are unloaded.  They are happy for me to come around and clean up all the seals.  I melt the zinc and toss the steel wire in the scrap can.  When I get enough accumulated wire scrap I head to the scrap yard.  Its a win-win all the way around.  I've not tried newer pennies, but why not?  I will caution you that zinc melts at a lower temp than aluminum so you need to add the solid zinc to the aluminum as the puddle forms.  I once tried just the opposite, the zinc overheated and caught fire, burning with a blue-white flame and created a horrible smoke that you do not want to breathe. The smoke turned the inside of my furnace white as it
                      oxidized in the atmosphere. 

                      I have also melted a few die-cast zinc motor frames from washing machine motors.
                      My personal experience with aluminum turnings is not good.  I just take the tops off the aluminum pop cans, put the chips in there and head to the scrap yard.  I also sell them my dross, yes, it is saleable.


                      Scott


                      [Non-text portions of this message have been removed]
                    • Jeshua Lacock
                      ... It has always been illegal to melt any money. It is called Destroying Government Property - and it is a prison-able offense. No thanks. Best, Jeshua
                      Message 10 of 19 , Aug 3, 2011
                        On Aug 3, 2011, at 6:53 PM, Evan Daniel wrote:

                        > As of late last
                        > year (iirc) melting down pennies or nickels for their metallurgical
                        > contents is prohibited. (The market value of the metals exceeds the
                        > face value of the coins.)

                        It has always been illegal to melt any money.

                        It is called "Destroying Government Property" - and it is a prison-able offense.

                        No thanks.


                        Best,

                        Jeshua Lacock, Owner
                        <http://OpenOSX.com>
                        phone: 208.462.4171
                      • Evan Daniel
                        ... Actually, the regulation is new, and it only applies to pennies and nickels: http://www.usatoday.com/money/2006-12-14-melting-ban-usat_x.htm Defacing or
                        Message 11 of 19 , Aug 3, 2011
                          On Wed, Aug 3, 2011 at 9:35 PM, Jeshua Lacock <jeshua@...> wrote:
                          >
                          > On Aug 3, 2011, at 6:53 PM, Evan Daniel wrote:
                          >
                          >> As of late last
                          >> year (iirc) melting down pennies or nickels for their metallurgical
                          >> contents is prohibited. (The market value of the metals exceeds the
                          >> face value of the coins.)
                          >
                          > It has always been illegal to melt any money.
                          >
                          > It is called "Destroying Government Property" - and it is a prison-able offense.
                          >
                          > No thanks.

                          Actually, the regulation is new, and it only applies to pennies and nickels:

                          http://www.usatoday.com/money/2006-12-14-melting-ban-usat_x.htm

                          Defacing or damaging currency *for the purpose of fraud* has always
                          been illegal. Doing it for non-fraudulent reasons other than the
                          metallurgical value is still legal. For example, it's OK to stamp
                          pennies into decorative things with those machines you'll often see at
                          museums and such, since the penny is being used as more than a source
                          of metal -- the fact that it started as a penny is part of the appeal.
                          Similarly, making art or doing science class demos with pennies and
                          nickels and other coins is fine.

                          You're still free to melt down other coins for their scrap value, it
                          just isn't profitable.

                          Evan Daniel
                        • Jeshua Lacock
                          ... That is true about decorative use. Wasn t aware of the educational use - but that makes sense. ... I am not positive that turning a shiny penny into a
                          Message 12 of 19 , Aug 3, 2011
                            On Aug 3, 2011, at 7:42 PM, Evan Daniel wrote:

                            > >
                            > > On Aug 3, 2011, at 6:53 PM, Evan Daniel wrote:
                            > >
                            > >> As of late last
                            > >> year (iirc) melting down pennies or nickels for their metallurgical
                            > >> contents is prohibited. (The market value of the metals exceeds the
                            > >> face value of the coins.)
                            > >
                            > > It has always been illegal to melt any money.
                            > >
                            > > It is called "Destroying Government Property" - and it is a prison-able offense.
                            > >
                            > > No thanks.
                            >
                            > Actually, the regulation is new, and it only applies to pennies and nickels:
                            >
                            > http://www.usatoday.com/money/2006-12-14-melting-ban-usat_x.htm
                            >
                            > Defacing or damaging currency *for the purpose of fraud* has always
                            > been illegal. Doing it for non-fraudulent reasons other than the
                            > metallurgical value is still legal. For example, it's OK to stamp
                            > pennies into decorative things with those machines you'll often see at
                            > museums and such, since the penny is being used as more than a source
                            > of metal -- the fact that it started as a penny is part of the appeal.
                            > Similarly, making art or doing science class demos with pennies and
                            > nickels and other coins is fine.

                            That is true about decorative use. Wasn't aware of the educational use - but that makes sense.

                            > You're still free to melt down other coins for their scrap value, it
                            > just isn't profitable.

                            I am not positive that turning a shiny penny into a potential lump of useless metal would hold up under the decorative use.

                            Regardless, I do know that I would not want to have to prove anything in front of judge and jury if I could at all avoid it.

                            ;)


                            Best,

                            Jeshua Lacock, Owner
                            <http://OpenOSX.com>
                            phone: 208.462.4171
                          • Evan Daniel
                            ... Basically, AIUI, if you re worried about the metal content of the coin for direct reasons, it s not ok. Indirect ones are OK (how do I design the pressing
                            Message 13 of 19 , Aug 3, 2011
                              On Wed, Aug 3, 2011 at 9:47 PM, Jeshua Lacock <jeshua@...> wrote:
                              >
                              > On Aug 3, 2011, at 7:42 PM, Evan Daniel wrote:
                              >
                              >> >
                              >> > On Aug 3, 2011, at 6:53 PM, Evan Daniel wrote:
                              >> >
                              >> >> As of late last
                              >> >> year (iirc) melting down pennies or nickels for their metallurgical
                              >> >> contents is prohibited. (The market value of the metals exceeds the
                              >> >> face value of the coins.)
                              >> >
                              >> > It has always been illegal to melt any money.
                              >> >
                              >> > It is called "Destroying Government Property" - and it is a prison-able offense.
                              >> >
                              >> > No thanks.
                              >>
                              >> Actually, the regulation is new, and it only applies to pennies and nickels:
                              >>
                              >> http://www.usatoday.com/money/2006-12-14-melting-ban-usat_x.htm
                              >>
                              >> Defacing or damaging currency *for the purpose of fraud* has always
                              >> been illegal. Doing it for non-fraudulent reasons other than the
                              >> metallurgical value is still legal. For example, it's OK to stamp
                              >> pennies into decorative things with those machines you'll often see at
                              >> museums and such, since the penny is being used as more than a source
                              >> of metal -- the fact that it started as a penny is part of the appeal.
                              >> Similarly, making art or doing science class demos with pennies and
                              >> nickels and other coins is fine.
                              >
                              > That is true about decorative use. Wasn't aware of the educational use - but that makes sense.
                              >
                              >> You're still free to melt down other coins for their scrap value, it
                              >> just isn't profitable.
                              >
                              > I am not positive that turning a shiny penny into a potential lump of useless metal would hold up under the decorative use.
                              >
                              > Regardless, I do know that I would not want to have to prove anything in front of judge and jury if I could at all avoid it.

                              Basically, AIUI, if you're worried about the metal content of the coin
                              for direct reasons, it's not ok. Indirect ones are OK (how do I design
                              the pressing machine given that pennies are mostly zinc?).

                              The relevant regulations aren't too hard to read, though I seem to
                              recall them being a little tricky to actually find online.

                              (Caveats: the above is my interpretation, not legal advice. And it's
                              been a while since I actually read the relevant regulations.)

                              Evan Daniel
                            • David Knaack
                              ... In case anyone is interested, below are the relevant parts of US law. Basically, as others have said, as long as it is clear that you do not intend to
                              Message 14 of 19 , Aug 3, 2011
                                On Wed, Aug 3, 2011 at 8:47 PM, Jeshua Lacock <jeshua@...> wrote:

                                > **
                                > On Aug 3, 2011, at 7:42 PM, Evan Daniel wrote:
                                > > > On Aug 3, 2011, at 6:53 PM, Evan Daniel wrote:
                                > > >
                                > > >> As of late last
                                > > >> year (iirc) melting down pennies or nickels for their metallurgical
                                > > >> contents is prohibited.
                                > > >
                                > > > It has always been illegal to melt any money.
                                > > >
                                > >
                                > > Actually, the regulation is new, and it only applies to pennies and
                                > nickels:
                                > >
                                >
                                > That is true about decorative use. Wasn't aware of the educational use -
                                > but that makes sense.
                                >
                                >
                                In case anyone is interested, below are the relevant parts of US law.

                                Basically, as others have said, as long as it is clear that you do not
                                intend to " profit solely from the value of the metal content of the coins",
                                you won't have a problem.

                                18 USC 331 : Mutilation, diminution, and falsification of coins
                                http://www.law.cornell.edu/uscode/18/usc_sec_18_00000331----000-.html

                                31 CFR Part 82 : 5-CENT AND ONE-CENT COIN REGULATIONS
                                http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=1614ed72dff41099a078a3e0f3e7530e&rgn=div5&view=text&node=31:1.2.1.1.2&idno=31

                                Here is the same as published in the Federal Register:
                                Federal Register / Vol. 72, No. 208 / Monday, October 29, 2007
                                http://www.usmint.gov/downloads/consumer/FederalRegisterNotice.pdf



                                § 82.1 Prohibitions.
                                Except as specifically authorized by the Secretary of the Treasury (or
                                designee) or as otherwise provided in this part, no person shall export,
                                melt, or treat:
                                (a) Any 5-cent coin of the United States; or
                                (b) Any one-cent coin of the United States.


                                § 82.2 Exceptions.
                                (b) The prohibition contained in §82.1 against the treatment of 5-cent coins
                                and one-cent coins shall not apply to the treatment of these coins for
                                educational, amusement, novelty, jewelry, and similar purposes as long as
                                the volumes treated and the nature of the treatment makes it clear that such
                                treatment is not intended as a means by which to profit solely from the
                                value of the metal content of the coins.

                                DaveK
                                (Also, first post to the list, hi!)


                                [Non-text portions of this message have been removed]
                              • John Junkroski
                                According to Money Week magazine, December 18, 2006. ... While melting certain coins for the value of their metal content is illegal, ... the regulation
                                Message 15 of 19 , Aug 3, 2011
                                  According to Money Week magazine,
                                  December 18, 2006.

                                  > Until this month, melting down coins hasn�t been illegal in the US.

                                  While melting certain coins for the value of their metal content is illegal,

                                  "... the regulation includes an exception for the treatment of 5-cent and one-cent coins for educational, amusement, novelty, jewelry, and similar purposes as long as the volumes treated and the nature of the treatment makes it clear that such treatment is not intended as a means by which to profit solely from the value of the metal content of the coins. "

                                  Excerpted from
                                  DEPARTMENT OF THE TREASURY
                                  Monetary Offices
                                  31 CFR Part 82

                                  I am not a lawyer, but that sounds pretty clear to me. I certainly wouldn't hesitate to use a few coins in a melt.
                                  Education? I always learn something from every melt. Amusement? My wife is consistently amused by my efforts, and it is certainly a novelty when one of my experiments succeeds.
                                  So I'm covered three ways under the exception.

                                  John



                                  On Aug 3, 2011, at 8:35 PM, Jeshua Lacock wrote:

                                  >
                                  > On Aug 3, 2011, at 6:53 PM, Evan Daniel wrote:
                                  >
                                  > > As of late last
                                  > > year (iirc) melting down pennies or nickels for their metallurgical
                                  > > contents is prohibited. (The market value of the metals exceeds the
                                  > > face value of the coins.)
                                  >
                                  > It has always been illegal to melt any money.
                                  >
                                  > It is called "Destroying Government Property" - and it is a prison-able offense.
                                  >
                                  > No thanks.
                                  >
                                  > Best,
                                  >
                                  > Jeshua Lacock, Owner
                                  > <http://OpenOSX.com>
                                  > phone: 208.462.4171
                                  >
                                  >



                                  [Non-text portions of this message have been removed]
                                • Jeshua Lacock
                                  ... Thanks David; it s been a while since I last read it. The word profit can be a very vague term. If you make a door handle, it could be argued that you
                                  Message 16 of 19 , Aug 3, 2011
                                    On Aug 3, 2011, at 8:11 PM, David Knaack wrote:

                                    > In case anyone is interested, below are the relevant parts of US law.
                                    >
                                    > Basically, as others have said, as long as it is clear that you do not
                                    > intend to " profit solely from the value of the metal content of the coins",
                                    > you won't have a problem.

                                    Thanks David; it's been a while since I last read it.

                                    The word "profit" can be a very vague term.

                                    If you make a door handle, it could be argued that you profited from the "metal content of the coins" everytime you opened the door.

                                    Or what if you sell a casting, are you profiting? That is; did it sell for more than the market value of the melt?


                                    Best,

                                    Jeshua Lacock, Owner
                                    <http://OpenOSX.com>
                                    phone: 208.462.4171
                                  • David Knaack
                                    ... I d suppose those uses would make it pretty clear that you were not profiting solely from the value of the metal. If you cast 1000 lbs of artistic door
                                    Message 17 of 19 , Aug 3, 2011
                                      On Wed, Aug 3, 2011 at 9:23 PM, Jeshua Lacock <jeshua@...> wrote:

                                      > **
                                      > On Aug 3, 2011, at 8:11 PM, David Knaack wrote:
                                      >
                                      > > In case anyone is interested, below are the relevant parts of US law.
                                      > >
                                      > > Basically, as others have said, as long as it is clear that you do not
                                      > > intend to " profit solely from the value of the metal content of the
                                      > coins",
                                      > > you won't have a problem.
                                      >
                                      > Thanks David; it's been a while since I last read it.
                                      >
                                      > The word "profit" can be a very vague term.
                                      >
                                      > If you make a door handle, it could be argued that you profited from the
                                      > "metal content of the coins" everytime you opened the door.
                                      >
                                      > Or what if you sell a casting, are you profiting? That is; did it sell for
                                      > more than the market value of the melt?
                                      >
                                      >
                                      I'd suppose those uses would make it pretty clear that you were not
                                      profiting solely from the value of the metal.

                                      If you cast 1000 lbs of artistic door handles, then took them to the scrap
                                      yard to sell for cash you'd probably be in violation.

                                      For my purposes, the value is clearly in the entertainment and novelty use.
                                      Here is how my pennies end up:

                                      https://picasaweb.google.com/davidknaack/20110605?authuser=0&authkey=Gv1sRgCJaqn7b4oLCodQ&feat=directlink

                                      DaveK


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                                    • raferjl
                                      I live in a suburb of Denver, Colorado. We bought our clay and sand at Mile Hi Ceramics. $20 for a 50 lb bag of fire cement, $20 for a 100 pound bag of 90
                                      Message 18 of 19 , Aug 3, 2011
                                        I live in a suburb of Denver, Colorado. We bought our clay and sand at Mile Hi Ceramics. $20 for a 50 lb bag of fire cement, $20 for a 100 pound bag of 90 mesh silica sand. They mostly cater to potters, and that ilk, but don't mind selling their products to us. It sure beats mail order.

                                        Does anybody have a good resource for finer sand in the Denver metro area?

                                        --- In hobbicast@yahoogroups.com, Evan Daniel <evand@...> wrote:
                                        >
                                        > On Wed, Aug 3, 2011 at 5:32 PM, raferjl <jim@...> wrote:
                                        > > Thank you to everyone for your replies.
                                        > >
                                        > > I've redesigned my liftout and pouring shanks to be two separate tools.  I'm using a similar pouring shank to the ones you see in myfordboy's youtube videos.  These have been dry run tested without scary hot molten metal.
                                        > >
                                        > > We're buying some bentonite clay to make a new batch of green sand.
                                        > > We'll probably mix it, and let it season for a day before use.
                                        > >
                                        > > A couple of responders have suggested using zinc or copper to help with free-flowing pours and machinability of the nearly-pure aluminum from extrusions.
                                        > >
                                        > > What do you think about using newer pennies as a source of zinc (plus a little copper)?  What are some other sources of scrap zinc?
                                        > >
                                        > > Also, what does the group think of using aluminum turning chips as a source of scrap aluminum?  I have a barrel full of mostly 6061 that is relatively oil free, that I could compact into bricks to charge the crucible.  They would probably create lots of oxide dross, but otherwise ok?
                                        >
                                        > You'll find the bentonite to be a big improvement. It's also worth
                                        > getting finer sand if you can find it locally. Where are you located?
                                        >
                                        > I've found chips and turnings to be more trouble than they're worth,
                                        > but mine have been slightly oily and not compressed.
                                        >
                                        > Pennies would work fine as a source of zinc (97.5 % Zn, 2.5% Cu),
                                        > except that they're illegal to use for such purposes. As of late last
                                        > year (iirc) melting down pennies or nickels for their metallurgical
                                        > contents is prohibited. (The market value of the metals exceeds the
                                        > face value of the coins.)
                                        >
                                        > Evan Daniel
                                        >
                                      • Matthew Tinker
                                        Scott, just a note on melting Al into Zn, you don t need to get the Zn up to Al melting temperatures, the Al will dissolve into the molten Zn. The same is true
                                        Message 19 of 19 , Aug 3, 2011
                                          Scott,

                                          just a note on melting Al into Zn, you don't need to get the Zn up to Al melting temperatures, the Al will dissolve into the molten Zn. The same is true of adding Cu to Al, again, the Cu will dissolve into the Al at below the melting point of Al.

                                          As you say the Zn "smoke" is a poison, it "happens" at 700°C,(the zinc boils)  just 60°C over the melting poiny of Al. The more zinc there is in the mixture, the lower the melting point of the alloy.

                                          Regards, Matthew

                                          Matthew TINKER

                                          CNC conversion 1944 Colchester Lathe build-up log

                                          http://www.cnczone.com/forums/showthread.php?t=35519

                                          --- On Thu, 4/8/11, Scott Trostel <blwloco@...> wrote:

                                          From: Scott Trostel <blwloco@...>
                                          Subject: Re: [hobbicast] Re: Questions after my first pour.
                                          To: "hobbicast@yahoogroups.com" <hobbicast@yahoogroups.com>
                                          Date: Thursday, 4 August, 2011, 3:02







                                           









                                          There are lots of sources for scrap zinc.  My favorite is three local plastic plants that get their pellets in railroad cars.  The discharge caps on the bottom of the cars are sealed with a steel wire and the locking bond is a chunk of zinc. They cut the wire and toss the seals to the side of the track as the cars are unloaded.  They are happy for me to come around and clean up all the seals.  I melt the zinc and toss the steel wire in the scrap can.  When I get enough accumulated wire scrap I head to the scrap yard.  Its a win-win all the way around.  I've not tried newer pennies, but why not?  I will caution you that zinc melts at a lower temp than aluminum so you need to add the solid zinc to the aluminum as the puddle forms.  I once tried just the opposite, the zinc overheated and caught fire, burning with a blue-white flame and created a horrible smoke that you do not want to breathe. The smoke turned the inside of my furnace white as
                                          it

                                          oxidized in the atmosphere. 



                                          I have also melted a few die-cast zinc motor frames from washing machine motors.

                                          My personal experience with aluminum turnings is not good.  I just take the tops off the aluminum pop cans, put the chips in there and head to the scrap yard.  I also sell them my dross, yes, it is saleable.



                                          Scott



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