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Re: [hobbicast] Yellow Brass Crucibles

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  • Foundryman
    I do a lot of yellow brass reproduction work for various customers. The wall thickness of my crucibles eventually builds up to the point that they are
    Message 1 of 14 , Nov 22, 2000
      I do a lot of yellow brass reproduction work for various customers. The
      wall thickness of my crucibles eventually builds up to the point that they
      are unusable--can't get much metal in the crucible. Now I scrape with the
      skimmer on each melt and have been able to remove a small bit of the crud
      with a very hot heat on an empty crucible.

      The question is, does anyone have a solution for cleaning a yellow brass
      crucible?

      Best, Jerry in Missouri
      Custom Castings by Twaddell
      foundryman@...
      http://members.igateway.net/~jtwad/
    • DEATHSTARR54@AOL.COM
      Jerry, Crucibles have to be cleaned after each brass heat. Use a steel scraper that conforms to the crucible. As soon as you are finished pigging, scrape up &
      Message 2 of 14 , Nov 22, 2000
        Jerry, Crucibles have to be cleaned after each brass heat. Use a steel
        scraper that conforms to the crucible. As soon as you are finished pigging,
        scrape up & down quickly on sides. If you don't do it right away, it's stuck.
        I have removed buildup with a screw driver after it's cool, but it takes a
        lot of meat with it. Crucibles don't crack until they are less than 1/2"
        thick, usually, and when they do they just dribble because the shank is
        holding it together. Steve in Spokane


        [Non-text portions of this message have been removed]
      • Jim
        Jerry, Sounds like it may be a zinc oxide buildup. Use an exothermic cleaning flux for bronze. You didn t say what material your crucible is made of. That may
        Message 3 of 14 , Nov 22, 2000
          Jerry,

          Sounds like it may be a zinc oxide buildup. Use an exothermic cleaning flux
          for bronze. You didn't say what material your crucible is made of. That may
          be part of the problem.

          Jim Clary

          ----- Original Message -----
          From: "Foundryman" <foundryman@...>
          To: <hobbicast@egroups.com>
          Sent: Wednesday, November 22, 2000 9:37 AM
          Subject: Re: [hobbicast] Yellow Brass Crucibles


          > I do a lot of yellow brass reproduction work for various customers. The
          > wall thickness of my crucibles eventually builds up to the point that they
          > are unusable--can't get much metal in the crucible. Now I scrape with the
          > skimmer on each melt and have been able to remove a small bit of the crud
          > with a very hot heat on an empty crucible.
          >
          > The question is, does anyone have a solution for cleaning a yellow brass
          > crucible?
          >
          > Best, Jerry in Missouri
          > Custom Castings by Twaddell
          > foundryman@...
          > http://members.igateway.net/~jtwad/
          >
          >
          > Please visit our sponsor: Budget Casting Supply
          > http://budgetcastingsupply.com/
          >
          > The Home Foundrymen's Association website may be found here:
          http://members.xoom.com/HWilkinson/index.htm
          > It includes member project pages & links
          >
          > To unsubscribe from this group, send an email to:
          > hobbicast-unsubscribe@egroups.com
          >
          >
          >
          >
        • Foundryman
          Jim, My crucibles are si-carbide. The crud buildup is dark colored and hard as a rock--not zinc oxide. Other than a bit of 20 Mule Team, I haven t been
          Message 4 of 14 , Nov 23, 2000
            Jim, My crucibles are si-carbide. The crud buildup is dark colored and
            hard as a rock--not zinc oxide. Other than a bit of 20 Mule Team, I haven't
            been fluxing yellow brass. I use a steel scraper after each pour, but the
            crud continues to build until the crucible is unusable.

            Best, Jerry in Missouri
            Custom Castings by Twaddell
            foundryman@...
            http://members.igateway.net/~jtwad/
          • Jim
            Jerry, Do you know the chemistry of the yellow brass you re melting? Jim Clary ... From: Foundryman To:
            Message 5 of 14 , Nov 23, 2000
              Jerry,

              Do you know the chemistry of the "yellow brass" you're melting?

              Jim Clary

              ----- Original Message -----
              From: "Foundryman" <foundryman@...>
              To: <hobbicast@egroups.com>
              Sent: Thursday, November 23, 2000 6:27 AM
              Subject: Re: [hobbicast] Yellow Brass Crucibles


              > Jim, My crucibles are si-carbide. The crud buildup is dark colored and
              > hard as a rock--not zinc oxide. Other than a bit of 20 Mule Team, I
              haven't
              > been fluxing yellow brass. I use a steel scraper after each pour, but the
              > crud continues to build until the crucible is unusable.
              >
              > Best, Jerry in Missouri
              > Custom Castings by Twaddell
              > foundryman@...
              > http://members.igateway.net/~jtwad/
              >
              >
              > Please visit our sponsor: Budget Casting Supply
              > http://budgetcastingsupply.com/
              >
              > The Home Foundrymen's Association website may be found here:
              http://members.xoom.com/HWilkinson/index.htm
              > It includes member project pages & links
              >
              > To unsubscribe from this group, send an email to:
              > hobbicast-unsubscribe@egroups.com
              >
              >
              >
              >
            • Foundryman
              Message 6 of 14 , Nov 23, 2000
                <Do you know the chemistry of the "yellow brass" you're melting>

                Jim, I do my yellow brass castings from ingots of 85400 otherwise known as
                403. The chemistry is app.. 67 copper 1 tin 3 lead and 29 zinc. You should
                know that in my repro work I cast .5 to 1 ton of yellow per year. in #10
                crucibles. I'm just hoping that there is an easy way to remove the buildup
                as opposed to chipping it out. Another point that make sense to you, I
                cycle my si-bronze crucibles to yellow brass when the wall thickness of the
                bronze crucible gets thin. But, I have the same problem when using a brand
                new carbide crucible. It seems a shame to discard a sound crucible.

                Best, Jerry in Missouri
                Custom Castings by Twaddell
                foundryman@...
                http://members.igateway.net/~jtwad/
              • Jim
                Jerry, How closely can you control the burner flame? It will change throughout the heating up of the entire furnace as combustion efficiency increases with the
                Message 7 of 14 , Nov 23, 2000
                  Jerry,

                  How closely can you control the burner flame? It will change throughout the
                  heating up of the entire furnace as combustion efficiency increases with the
                  rise in temperature. This problem is common with open venturi type burners.
                  The gas setting you start with, with a cold furnace is usually not the
                  correct setting for a hot furnace, unless you have a proportioning mixer
                  that is driven off the air stream and a very efficient burner, one that
                  completely mixes the air and gas before it reaches the flame front. The
                  reason for this is that few of these types of burners completely mix the air
                  and gas before it reaches the flame point and so what burns is only what is
                  mixed even though there is too much or too little gas or air. This gives you
                  a false reading on your setting. It looks correct but it is not. As the
                  inside of the furnace heats up the mix "goes lean" and what started out as a
                  dead on setting ends up as a reducing atmosphere for all the time you are
                  melting the brass. The quick answer to this is to re-set your gas setting
                  again after the furnace is at full operating temperature. Have you noticed
                  if the build up is greater with a reducing or oxidizing flame? I had a
                  similar problem using this type burner with red brass about 40 years ago. My
                  problem was a too reducing flame (too lean). That furnace would convert an
                  entire #20 crucible (60lbs) of brass to dross in less than an hour. When I
                  richened it up to just slightly oxidizing and monitored it to keep it at
                  that setting, the problem went away. If you're going to error with the
                  burner setting, error on the rich side. We should be able to figure out how
                  to stop the build up as opposed to resorting to chipping it out. Who do you
                  get the ingot from?

                  Jim Clary

                  ----- Original Message -----
                  From: "Foundryman" <foundryman@...>
                  To: <hobbicast@egroups.com>
                  Sent: Thursday, November 23, 2000 4:26 PM
                  Subject: Re: [hobbicast] Yellow Brass Crucibles


                  > <Do you know the chemistry of the "yellow brass" you're melting>
                  >
                  > Jim, I do my yellow brass castings from ingots of 85400 otherwise known
                  as
                  > 403. The chemistry is app.. 67 copper 1 tin 3 lead and 29 zinc. You
                  should
                  > know that in my repro work I cast .5 to 1 ton of yellow per year. in #10
                  > crucibles. I'm just hoping that there is an easy way to remove the
                  buildup
                  > as opposed to chipping it out. Another point that make sense to you, I
                  > cycle my si-bronze crucibles to yellow brass when the wall thickness of
                  the
                  > bronze crucible gets thin. But, I have the same problem when using a
                  brand
                  > new carbide crucible. It seems a shame to discard a sound crucible.
                  >
                  > Best, Jerry in Missouri
                  > Custom Castings by Twaddell
                  > foundryman@...
                  > http://members.igateway.net/~jtwad/
                  >
                  >
                  > Please visit our sponsor: Budget Casting Supply
                  > http://budgetcastingsupply.com/
                  >
                  > The Home Foundrymen's Association website may be found here:
                  http://members.xoom.com/HWilkinson/index.htm
                  > It includes member project pages & links
                  >
                  > To unsubscribe from this group, send an email to:
                  > hobbicast-unsubscribe@egroups.com
                  >
                  >
                  >
                  >
                • Robert Grauman
                  ... As the ... a ... My ... Hello Jim, Is this correct? I have always understood that when the flame is adjusted lean, there is an excess of oxygen in the
                  Message 8 of 14 , Nov 23, 2000
                    >
                    As the
                    > inside of the furnace heats up the mix "goes lean" and what started out as
                    a
                    > dead on setting ends up as a reducing atmosphere for all the time you are
                    > melting the brass. The quick answer to this is to re-set your gas setting
                    > again after the furnace is at full operating temperature. Have you noticed
                    > if the build up is greater with a reducing or oxidizing flame? I had a
                    > similar problem using this type burner with red brass about 40 years ago.
                    My
                    > problem was a too reducing flame (too lean). That furnace would convert an
                    > entire #20 crucible (60lbs) of brass to dross in less than an hour. When I
                    > richened it up to just slightly oxidizing and monitored it to keep it at
                    > that setting, the problem went away. If you're going to error with the
                    > burner setting, error on the rich side.


                    Hello Jim,

                    Is this correct? I have always understood that when the flame is adjusted
                    lean, there is an excess of oxygen in the flame, and it is therefore an
                    oxidizing flame. Conversely, when there is an excess of fuel in the flame,
                    it is a reducing flame. We always adjust for a slightly reducing flame
                    (excess fuel).

                    We have found that the mixture in our simple burners does lean out during
                    the burn, and we adjust our mixture as the burn progress.

                    Robert Grauman in Sunny Alberta
                  • Jim
                    Robert, Sorry, of course you re right. Guess I was having a senior moment! That didn t sound quite right when I finished and posted it! Jim Clary ... From:
                    Message 9 of 14 , Nov 23, 2000
                      Robert,

                      Sorry, of course you're right. Guess I was having a "senior moment!" That
                      didn't sound quite right when I finished and posted it!

                      Jim Clary

                      ----- Original Message -----
                      From: "Robert Grauman" <rgrauman@...>
                      To: <hobbicast@egroups.com>
                      Sent: Thursday, November 23, 2000 10:04 PM
                      Subject: Re: [hobbicast] Yellow Brass Crucibles


                      > >
                      > As the
                      > > inside of the furnace heats up the mix "goes lean" and what started out
                      as
                      > a
                      > > dead on setting ends up as a reducing atmosphere for all the time you
                      are
                      > > melting the brass. The quick answer to this is to re-set your gas
                      setting
                      > > again after the furnace is at full operating temperature. Have you
                      noticed
                      > > if the build up is greater with a reducing or oxidizing flame? I had a
                      > > similar problem using this type burner with red brass about 40 years
                      ago.
                      > My
                      > > problem was a too reducing flame (too lean). That furnace would convert
                      an
                      > > entire #20 crucible (60lbs) of brass to dross in less than an hour. When
                      I
                      > > richened it up to just slightly oxidizing and monitored it to keep it at
                      > > that setting, the problem went away. If you're going to error with the
                      > > burner setting, error on the rich side.
                      >
                      >
                      > Hello Jim,
                      >
                      > Is this correct? I have always understood that when the flame is adjusted
                      > lean, there is an excess of oxygen in the flame, and it is therefore an
                      > oxidizing flame. Conversely, when there is an excess of fuel in the
                      flame,
                      > it is a reducing flame. We always adjust for a slightly reducing flame
                      > (excess fuel).
                      >
                      > We have found that the mixture in our simple burners does lean out during
                      > the burn, and we adjust our mixture as the burn progress.
                      >
                      > Robert Grauman in Sunny Alberta
                      >
                      >
                      >
                      > Please visit our sponsor: Budget Casting Supply
                      > http://budgetcastingsupply.com/
                      >
                      > The Home Foundrymen's Association website may be found here:
                      http://members.xoom.com/HWilkinson/index.htm
                      > It includes member project pages & links
                      >
                      > To unsubscribe from this group, send an email to:
                      > hobbicast-unsubscribe@egroups.com
                      >
                      >
                      >
                      >
                    • Foundryman
                      Jim, I get my yellow brass from H. Kramer Co. out of Chicago. Thanks for your and Robert s comments. Robert, I m surprised by your comment that you use a
                      Message 10 of 14 , Nov 24, 2000
                        Jim, I get my yellow brass from H. Kramer Co. out of Chicago. Thanks for
                        your and Robert's comments. Robert, I'm surprised by your comment that you
                        use a slightly reducing flame. Everything I've read and I've always used a
                        slightly oxidizing flame! With my furnaces, I can control both air and gas.
                        But I should be doing a better job. I'm usually ramming or doing finish
                        work while a melt is in progress and don't check or adjust the flame until
                        making the first add. Last weekend, for example, we cast 13 fairly large
                        pieces in red brass (85-5-5-5) and shipped 97.5 pounds of castings. The
                        first melt produced a fair amount of dross, but subsequent melts, with a HOT
                        furnace produced very little dross. I think this tracks with your comments.

                        Best, Jerry in Missouri
                        Custom Castings by Twaddell
                        foundryman@...
                        http://members.igateway.net/~jtwad/
                      • Robert Grauman
                        ... Hello Jim, Isn t that the way it always works? You make a little slip of the tongue, and there s some smart ass laying in the weeds, just waiting to jump
                        Message 11 of 14 , Nov 24, 2000
                          > Robert,
                          >
                          > Sorry, of course you're right. Guess I was having a "senior moment!" That
                          > didn't sound quite right when I finished and posted it!
                          >
                          > Jim Clary

                          Hello Jim,

                          Isn't that the way it always works? You make a little slip of the tongue,
                          and there's some smart ass laying in the weeds, just waiting to jump all
                          over you!!

                          Robert Grauman in Sunny Alberta
                        • Jim
                          Robert, So glad you did, Robert, and promptly Too! Maybe I should be totally awake when I do this. Some times, like last night I do postings when I should be
                          Message 12 of 14 , Nov 24, 2000
                            Robert,

                            So glad you did, Robert, and promptly Too! Maybe I should be totally awake
                            when I do this. Some times, like last night I do postings when I should be
                            sleeping. But we got it straightened out, thanks to you Robert. I'm
                            delighted you caught it so quickly! Keep an eye on me, buddy, sometimes I
                            make a major one like that. I guess I'm getting rapidly into that "senior
                            moment group".

                            Thanks again, Robert,

                            Jim Clary

                            ----- Original Message -----
                            From: "Robert Grauman" <rgrauman@...>
                            To: <hobbicast@egroups.com>
                            Sent: Thursday, November 23, 2000 10:04 PM
                            Subject: Re: [hobbicast] Yellow Brass Crucibles


                            > >
                            > As the
                            > > inside of the furnace heats up the mix "goes lean" and what started out
                            as
                            > a
                            > > dead on setting ends up as a reducing atmosphere for all the time you
                            are
                            > > melting the brass. The quick answer to this is to re-set your gas
                            setting
                            > > again after the furnace is at full operating temperature. Have you
                            noticed
                            > > if the build up is greater with a reducing or oxidizing flame? I had a
                            > > similar problem using this type burner with red brass about 40 years
                            ago.
                            > My
                            > > problem was a too reducing flame (too lean). That furnace would convert
                            an
                            > > entire #20 crucible (60lbs) of brass to dross in less than an hour. When
                            I
                            > > richened it up to just slightly oxidizing and monitored it to keep it at
                            > > that setting, the problem went away. If you're going to error with the
                            > > burner setting, error on the rich side.
                            >
                            >
                            > Hello Jim,
                            >
                            > Is this correct? I have always understood that when the flame is adjusted
                            > lean, there is an excess of oxygen in the flame, and it is therefore an
                            > oxidizing flame. Conversely, when there is an excess of fuel in the
                            flame,
                            > it is a reducing flame. We always adjust for a slightly reducing flame
                            > (excess fuel).
                            >
                            > We have found that the mixture in our simple burners does lean out during
                            > the burn, and we adjust our mixture as the burn progress.
                            >
                            > Robert Grauman in Sunny Alberta
                            >
                            >
                            >
                            > Please visit our sponsor: Budget Casting Supply
                            > http://budgetcastingsupply.com/
                            >
                            > The Home Foundrymen's Association website may be found here:
                            http://members.xoom.com/HWilkinson/index.htm
                            > It includes member project pages & links
                            >
                            > To unsubscribe from this group, send an email to:
                            > hobbicast-unsubscribe@egroups.com
                            >
                            >
                            >
                            >
                          • Robert Grauman
                            ... a ... Hello Jerry, I am basing my comments mainly on my limited experience with oxy-acetylene welding. I was always taught to adjust the flame to be
                            Message 13 of 14 , Nov 24, 2000
                              > Robert, I'm surprised by your comment that you
                              > use a slightly reducing flame. Everything I've read and I've always used
                              a
                              > slightly oxidizing flame!

                              Hello Jerry,

                              I am basing my comments mainly on my limited experience with oxy-acetylene
                              welding. I was always taught to adjust the flame to be slightly reducing
                              a little beard on the inner cone) so that you were certain that the flame
                              was not oxidizing. When welding most metals, an oxidizing flame was not
                              desirable, and I just transferred this concept to my melting practice.
                              Intuitively, I feel that much of the dross we get are oxides, so if we can
                              minimize the contact that molten metal has with oxygen, we may be able to
                              decrease the oxidation process to some extent. Flux covers do the same job
                              as well. Please note that I can't quote any references to back up my
                              statements, so I may be wrong. Wouldn't be the first time.

                              I would like to point out, however, that running the flame rich produces
                              carbon monoxide, so you must provide good ventilation in your foundry to
                              avoid poisoning yourself. I have found that I can set the flame to be
                              slightly reducing by carefully observing the exhaust hole on the furnace.
                              When the flame is reducing, there will be a small tongue of flame at the
                              exhaust hole. This is carbon monoxide flaring off, I am certain. I seem to
                              get my best results when this flame is present, but adjusted to be as small
                              as possible. I found that I could best see this flame at night, and taught
                              myself by observing a few night melts.

                              Robert Grauman in Sunny Alberta
                            • geoff
                              Hi, just geoff here. Today i poured several sea shells and a fiche plate, all for my wife. She really likes the pours like this. She is an art teacher
                              Message 14 of 14 , Nov 24, 2000
                                Hi, just geoff here. Today i poured several sea shells and a fiche plate,
                                all for my wife. She really likes the pours like this. She is an art
                                teacher and i find things go much smoother when she's happy. This way i
                                don't have complaints when i want to buy foundry equipment; such as ,
                                "Honey, think how mant stars and shells i could pour if i had a number
                                twenty crucible. gr
                                -----Original Message-----b
                                eFrom: Robert Grauman <rgrauman@...>
                                To: hobbicast@egroups.com <hobbicast@egroups.com>
                                Date: Friday, November 24, 2000 10:50 AM
                                Subject: Re: [hobbicast] Yellow Brass Crucibles


                                >> Robert, I'm surprised by your comment that you
                                >> use a slightly reducing flame. Everything I've read and I've always used
                                >a
                                >> slightly oxidizing flame!
                                >
                                >Hello Jerry,
                                >
                                >I am basing my comments mainly on my limited experience with oxy-acetylene
                                >welding. I was always taught to adjust the flame to be slightly reducing
                                > a little beard on the inner cone) so that you were certain that the flame
                                >was not oxidizing. When welding most metals, an oxidizing flame was not
                                >desirable, and I just transferred this concept to my melting practice.
                                >Intuitively, I feel that much of the dross we get are oxides, so if we can
                                >minimize the contact that molten metal has with oxygen, we may be able to
                                >decrease the oxidation process to some extent. Flux covers do the same job
                                >as well. Please note that I can't quote any references to back up my
                                >statements, so I may be wrong. Wouldn't be the first time.
                                >
                                >I would like to point out, however, that running the flame rich produces
                                >carbon monoxide, so you must provide good ventilation in your foundry to
                                >avoid poisoning yourself. I have found that I can set the flame to be
                                >slightly reducing by carefully observing the exhaust hole on the furnace.
                                >When the flame is reducing, there will be a small tongue of flame at the
                                >exhaust hole. This is carbon monoxide flaring off, I am certain. I seem
                                to
                                >get my best results when this flame is present, but adjusted to be as small
                                >as possible. I found that I could best see this flame at night, and taught
                                >myself by observing a few night melts.
                                >
                                > Robert Grauman in Sunny Alberta
                                >
                                >
                                >
                                >Please visit our sponsor: Budget Casting Supply
                                >http://budgetcastingsupply.com/
                                >
                                >The Home Foundrymen's Association website may be found here:
                                http://members.xoom.com/HWilkinson/index.htm
                                >It includes member project pages & links
                                >
                                >To unsubscribe from this group, send an email to:
                                >hobbicast-unsubscribe@egroups.com
                                >
                                >
                                >
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