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brass porosity

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  • ferroman1000
    Hi, I am new to the group. My interest in casting is because I make model stationary steam engines. There is one problem that I have is constant porosity in
    Message 1 of 16 , Oct 5, 2010
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      Hi, I am new to the group. My interest in casting is because I make model stationary steam engines. There is one problem that I have is constant porosity in brass. I use heavy walled steel pipe as a mould for round bar. I have tried every thing I can think of, such as preheating the mould, pouring at lower temps. The porosity is always just under the surface and I never have this prolem with aluminium. Any ideas?
      Cheers Ernie.
    • Scrolling8
      I have experienced that when doing brass pours in the fall when the air is quite dry the amount of porosity is reduced. So my recomendation would be to work
      Message 2 of 16 , Oct 5, 2010
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        I have experienced that when doing brass pours in the fall when the air is quite dry the amount of porosity is reduced. So my recomendation would be to work around the weather and don't pour on a humid day, keep your moulds dry, and provide wells that reduce the distance between your ladle and the top of the mould so that the possible exposure to damp air is reduced to a minimum. Also reduce the time between getting to temp and pouring by having everything ready to go.




        -----Original Message-----
        From: ferroman1000 <ferroman1000@...>
        To: hobbicast@yahoogroups.com
        Sent: Tue, Oct 5, 2010 6:25 pm
        Subject: [hobbicast] brass porosity




        Hi, I am new to the group. My interest in casting is because I make model stationary steam engines. There is one problem that I have is constant porosity in brass. I use heavy walled steel pipe as a mould for round bar. I have tried every thing I can think of, such as preheating the mould, pouring at lower temps. The porosity is always just under the surface and I never have this prolem with aluminium. Any ideas?
        Cheers Ernie.







        [Non-text portions of this message have been removed]
      • David Patterson
        do you have pictures? Dave Patterson odd_kins@yahoo.com http://home.comcast.net/~oddkins/foundry_home.html ... From: ferroman1000
        Message 3 of 16 , Oct 5, 2010
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          do you have pictures?

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

          --- On Tue, 10/5/10, ferroman1000 <ferroman1000@...> wrote:


          From: ferroman1000 <ferroman1000@...>
          Subject: [hobbicast] brass porosity
          To: hobbicast@yahoogroups.com
          Date: Tuesday, October 5, 2010, 4:25 PM


           



          Hi, I am new to the group. My interest in casting is because I make model stationary steam engines. There is one problem that I have is constant porosity in brass. I use heavy walled steel pipe as a mould for round bar. I have tried every thing I can think of, such as preheating the mould, pouring at lower temps. The porosity is always just under the surface and I never have this prolem with aluminium. Any ideas?
          Cheers Ernie.











          [Non-text portions of this message have been removed]
        • Rupert
          Hello Ernie, Besides what has already been said, there is a possibility that the pipe is cool enough to cause droplets to freeze on the pipe sides that trap
          Message 4 of 16 , Oct 5, 2010
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            Hello Ernie,
            Besides what has already been said, there is a possibility that the
            pipe is cool enough to cause droplets to freeze on the pipe sides that
            trap air as the pipe fills. I would think the pipe should be almost red
            hot not to get chill problems when pouring brass into it.
            I've only tried using a pipe mold once and that was a disaster. The
            pipe I used had a zinc coating. I figured the zinc would melt and blend
            with the melt but it didn't. My thoughts from that experiment indicate
            that the only coating that might work is a liberal coating of graphite
            or just let rust coat the inside. Otherwise, the pipe must be
            scrupulously clean. Make sure the pipe is good and hot when you pour.

            Rupert
            Ps. I push a pipe into molding sand to make round stock for my projects.
            I also save my sprues and risers for round stock.

            On 10/5/2010 7:44 PM, David Patterson wrote:
            > do you have pictures?
            >
            > Dave Patterson
            > odd_kins@...
            > http://home.comcast.net/~oddkins/foundry_home.html
            >
            > --- On Tue, 10/5/10, ferroman1000<ferroman1000@...> wrote:
            >
            >
            > From: ferroman1000<ferroman1000@...>
            > Subject: [hobbicast] brass porosity
            > To: hobbicast@yahoogroups.com
            > Date: Tuesday, October 5, 2010, 4:25 PM
            >
            >
            >
            >
            >
            >
            > Hi, I am new to the group. My interest in casting is because I make model stationary steam engines. There is one problem that I have is constant porosity in brass. I use heavy walled steel pipe as a mould for round bar. I have tried every thing I can think of, such as preheating the mould, pouring at lower temps. The porosity is always just under the surface and I never have this prolem with aluminium. Any ideas?
            > Cheers Ernie.
            >
            >
            >
            >
            >
            >
            >
            >
            >
            >
            >
            > [Non-text portions of this message have been removed]
            >
            >
            >
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            yvt

            Rupert Wenig
            Camrose, Alberta, Canada.

            email: rwenig2@...

            http://users.xplornet.com/~rwenig/Home/
          • Rupert
            Hello Ernie, I added a line to my message to correct myself. ... I ve only tried ... -- yvt Rupert Wenig Camrose, Alberta, Canada. email: rwenig2@xplornet.com
            Message 5 of 16 , Oct 5, 2010
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              Hello Ernie,
              I added a line to my message to correct myself.

              On 10/5/2010 9:05 PM, Rupert wrote:
              > Hello Ernie, Besides what has already been said, there is a
              > possibility that the pipe is cool enough to cause droplets to freeze
              > on the pipe sides that trap air as the pipe fills. Remember the pour
              > will be splashing metal onto the sides of the pipe. This will be
              > particularly noticeable near the bottom and get less noticeable as
              > the pipe fills. I would think the pipe should be almost red hot not
              > to get chill problems when pouring brass into it.

              I've only tried
              > using a pipe mold once and that was a disaster. The pipe I used had a
              > zinc coating. I figured the zinc would melt and blend with the melt
              > but it didn't. My thoughts from that experiment indicate that the
              > only coating that might work is a liberal coating of graphite or just
              > let rust coat the inside. Otherwise, the pipe must be scrupulously
              > clean. Make sure the pipe is good and hot when you pour.
              >
              > Rupert Ps. I push a pipe into molding sand to make round stock for
              > my projects. I also save my sprues and risers for round stock.
              >
              --

              yvt

              Rupert Wenig
              Camrose, Alberta, Canada.

              email: rwenig2@...

              http://users.xplornet.com/~rwenig/Home/
            • Gary R
              I m sure somebody must have mentioned degassing the melt, but I must have missed it. GaryR
              Message 6 of 16 , Oct 6, 2010
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                I'm sure somebody must have mentioned degassing the melt, but I must have missed it.

                GaryR

                --- In hobbicast@yahoogroups.com, Rupert <rwenig2@...> wrote:
                >
                > Hello Ernie,
                > I added a line to my message to correct myself.
                >
                > On 10/5/2010 9:05 PM, Rupert wrote:
                > > Hello Ernie, Besides what has already been said, there is a
                > > possibility that the pipe is cool enough to cause droplets to freeze
                > > on the pipe sides that trap air as the pipe fills. Remember the pour
                > > will be splashing metal onto the sides of the pipe. This will be
                > > particularly noticeable near the bottom and get less noticeable as
                > > the pipe fills. I would think the pipe should be almost red hot not
                > > to get chill problems when pouring brass into it.
                >
                > I've only tried
                > > using a pipe mold once and that was a disaster. The pipe I used had a
                > > zinc coating. I figured the zinc would melt and blend with the melt
                > > but it didn't. My thoughts from that experiment indicate that the
                > > only coating that might work is a liberal coating of graphite or just
                > > let rust coat the inside. Otherwise, the pipe must be scrupulously
                > > clean. Make sure the pipe is good and hot when you pour.
                > >
                > > Rupert Ps. I push a pipe into molding sand to make round stock for
                > > my projects. I also save my sprues and risers for round stock.
                > >
                > --
                >
                > yvt
                >
                > Rupert Wenig
                > Camrose, Alberta, Canada.
                >
                > email: rwenig2@...
                >
                > http://users.xplornet.com/~rwenig/Home/
                >
              • Kerri Duncan
                Gary and guys- I am going to attempt to cast a few ingots and things out of brass in the next month or so- I am reading the archives and this thread with some
                Message 7 of 16 , Oct 6, 2010
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                  Gary and guys- I am going to attempt to cast a few ingots and things out of brass in the next month or so- I am reading the archives and this thread with some trepidation though... Not that brass is some monster- but as a first timer I am wanting to make sure I have the basics...
                   
                  Not trying to hijack the thread- but porosity issues seem to be the biggest issue for several folks... Here is my take on the process and its potential pitfalls... please correct me or feel free to give suggestions if I am off base-
                   
                  1-Use a crucible just for Brass- with a lid or at least a cover of carbon/charcoal/glass/sand on the charge... keeps out excess Oxygen...
                  2- Flux has been mentioned by folks- laundry Borax and Boric Acid both have been brought up in different places... A teaspoon when the crucible is heatng to glass it over and then a bit when you place the charge in the crucible at start heat...
                  3- dont skim till you are ready to pour- dont de-gass till you are ready to pour...skimming THEN de-gassing... Or is it the other way around to preserve the protective coating on the surface of the melt?
                  4- pour at temp or just above for your alloy- too high and the casting surface suffers...
                   
                  Is the solidification of Brass important to leave IN the mold/flask till it is cool or does an early shake-out affect the surface coloration/Integrity?
                   
                  Sorry for the blast- I am just trying to understand the variables in the equation before I get to it... that way when I DO have a problem... and I am sure I will... I will have SOME ideas for where to troubleshoot...
                   
                  Ernie- How would you get the brass out of the pipe you casted the round-stock in? grind and peel? Thanks for starting this thread!
                   
                  Kerri

                  [Non-text portions of this message have been removed]
                • Lyle
                  For some types of brass, you don t need a cover flux so make sure you know what type of brass your pouring. I don t use a cover flux for any brass. I do
                  Message 8 of 16 , Oct 6, 2010
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                    For some types of brass, you don't need a cover flux so make sure you know what type of brass your pouring. I don't use a cover flux for any brass. I do (sometimes) degass with a little phospher/copper welding rod, just a bit and I do this just a few minutes prior to pouring. I usually only degass if I'm pouring scrap.

                    Sometimes, if I'm in a hurry, I shake out within just a few munites. Watch out for the extremely hot sand though. We just did 23 molds over the weekend this way.

                    If I were to start with no experiience, I'd try to get some silicon bronze such 513B (technically a brass) and go from there. My second choice would be a mag bronze (420 series) as neither needs a cover flux. You can test scrap for both of them with chemicals. Oh, and use a brand new crucible. If you use a crucible that had leaded brass in it, and then use it for silicon bronze, you'll ruin your crucible and your melt.

                    LL




                    --- In hobbicast@yahoogroups.com, Kerri Duncan <silverforgestudio@...> wrote:
                    >
                    > Gary and guys- I am going to attempt to cast a few ingots and things out of brass in the next month or so- I am reading the archives and this thread with some trepidation though... Not that brass is some monster- but as a first timer I am wanting to make sure I have the basics...
                    >  
                    > Not trying to hijack the thread- but porosity issues seem to be the biggest issue for several folks... Here is my take on the process and its potential pitfalls... please correct me or feel free to give suggestions if I am off base-
                    >  
                    > 1-Use a crucible just for Brass- with a lid or at least a cover of carbon/charcoal/glass/sand on the charge... keeps out excess Oxygen...
                    > 2- Flux has been mentioned by folks- laundry Borax and Boric Acid both have been brought up in different places... A teaspoon when the crucible is heatng to glass it over and then a bit when you place the charge in the crucible at start heat...
                    > 3- dont skim till you are ready to pour- dont de-gass till you are ready to pour...skimming THEN de-gassing... Or is it the other way around to preserve the protective coating on the surface of the melt?
                    > 4- pour at temp or just above for your alloy- too high and the casting surface suffers...
                    >  
                    > Is the solidification of Brass important to leave IN the mold/flask till it is cool or does an early shake-out affect the surface coloration/Integrity?
                    >  
                    > Sorry for the blast- I am just trying to understand the variables in the equation before I get to it... that way when I DO have a problem... and I am sure I will... I will have SOME ideas for where to troubleshoot...
                    >  
                    > Ernie- How would you get the brass out of the pipe you casted the round-stock in? grind and peel? Thanks for starting this thread!
                    >  
                    > Kerri
                    >
                    > [Non-text portions of this message have been removed]
                    >
                  • Lyle
                    I ve had the same problem pouring aluminum into steel molds if they weren t hot enough. I used to pour my own plain matchplates between two steel plates. That
                    Message 9 of 16 , Oct 6, 2010
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                      I've had the same problem pouring aluminum into steel molds if they weren't hot enough. I used to pour my own plain matchplates between two
                      steel plates. That porosity problem would sometime occur on the thicker plate side of the casting.

                      Can't you ram up a flask and push a sprue cutter through the same to make a bunch of cylindrical molds? Or, just buy brass bar stock. I know I'm not snswering your question but am suggesting some alternatives.



                      --- In hobbicast@yahoogroups.com, "ferroman1000" <ferroman1000@...> wrote:
                      >
                      > Hi, I am new to the group. My interest in casting is because I make model stationary steam engines. There is one problem that I have is constant porosity in brass. I use heavy walled steel pipe as a mould for round bar. I have tried every thing I can think of, such as preheating the mould, pouring at lower temps. The porosity is always just under the surface and I never have this prolem with aluminium. Any ideas?
                      > Cheers Ernie.
                      >
                    • Dan Brewer
                      If you can follow established rules for gating your pour you should not entrain ir into you casting. Try to use sand for the mold. Use rectangular gating , a
                      Message 10 of 16 , Oct 6, 2010
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                        If you can follow established rules for gating your pour you should not
                        entrain ir into you casting. Try to use sand for the mold. Use rectangular
                        gating , a pouring basin at the end of your spru, and pouring cup at the
                        top. this should keep the sand from beeing trapped in the pour and air
                        being mixed with the molten metal as you pour.
                        Dan in Auburn


                        [Non-text portions of this message have been removed]
                      • Carlos Contreras
                        Hi Ernie,   Let me tell you that the therm porosity defect ,in foundry´s are very polemic...   and it is becouse the couse for porosity in a foundry
                        Message 11 of 16 , Oct 6, 2010
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                          Hi Ernie,
                           
                          Let me tell you that the therm "porosity defect",in foundry´s are very polemic...
                           
                          and it is becouse the couse for porosity in a foundry casting can be:
                           
                          - Air entrapment during the pouring
                          - Gas coming from the mould
                          - mould to cool (for metalic moulds)
                          - gas in the liqued metal (nitrogen or Hydrogen), depend on the alloy
                          - reaction betwen mould and metal.
                          - contamination of the alloy in case of red brass, a very small amount of aluminum in the alloy cause undersurface porosity, the shape of the porus are large porosity like termits in the wood.
                           
                          So if you can give us more datails about the type of alloy, your tipe of furnace and a picture of the porus in the castng then we can have more information to help you.
                           
                          with the information you mentioned, I can recomend.
                           
                          1.- be sure the tube (mold), are clean, and coat it with graphite coating.
                          2.- be sure the mouls is around 200 to 260 celsius degrees before pouring
                          3.- be sure you deoxidate the metal adding cooper phospurus just before pouring
                          4.- if is red brass, before deoxidate, you hace to de-gas the metal adding some product (LOGAS), that produce CO and CO2 boubles that take out the diseolved gas (hidrogen usualy) from the metal.
                           
                          if you can turn some degrees the mould to pur it and avoid the hit and splash of metal in the bottom of the mould it will help to avoid turbulende that can trao air in to the metal.
                           
                          be sure the temperature of the metal is good (qround 1180 - 1200 celsius degrees depend on the allloy. (50 celsius degrees over the liquidus temperature of the particular alloy), just before pour the mould.
                           
                          check this link.
                           
                          http://www.neon-john.com/Misc/ebooks/Foseco_Non-Ferrous_Foundrymans_Handbook_11thed.-J.Brown.pdf
                           
                          Hope it can help you.
                           
                          All the Best
                           
                          J.Luis
                          Foundry consultant for Mexico and Latin America

                          --- El mar 5-oct-10, ferroman1000 <ferroman1000@...> escribió:


                          De: ferroman1000 <ferroman1000@...>
                          Asunto: [hobbicast] brass porosity
                          A: hobbicast@yahoogroups.com
                          Fecha: martes, 5 de octubre de 2010, 23:25


                           



                          Hi, I am new to the group. My interest in casting is because I make model stationary steam engines. There is one problem that I have is constant porosity in brass. I use heavy walled steel pipe as a mould for round bar. I have tried every thing I can think of, such as preheating the mould, pouring at lower temps. The porosity is always just under the surface and I never have this prolem with aluminium. Any ideas?
                          Cheers Ernie.











                          [Non-text portions of this message have been removed]
                        • Dick Morris
                          ... Very interesting. I learned several things in a quick perusal. The description of lost foam was very informative. Thanks! Dick Morris Anchorage, Alaska
                          Message 12 of 16 , Oct 7, 2010
                          • 0 Attachment
                            At 07:51 PM 10/6/2010, you wrote:
                            >check this link.
                            >
                            >http://www.neon-john.com/Misc/ebooks/Foseco_Non-Ferrous_Foundrymans_Handbook_11thed.-J.Brown.pdf
                            >

                            Very interesting. I learned several things in a quick perusal. The
                            description of lost foam was very informative. Thanks!


                            Dick Morris
                            Anchorage, Alaska
                          • Nick Andrews
                            I guess he doesn t have the third section on iron casting there, but a ton of other interesting books for sure! ... -- Nick A You know what I wish? I wish
                            Message 13 of 16 , Oct 7, 2010
                            • 0 Attachment
                              I guess he doesn't have the third section on iron casting there, but a ton
                              of other interesting books for sure!

                              On Wed, Oct 6, 2010 at 9:51 PM, Carlos Contreras <maximo64@...>wrote:

                              >
                              >
                              > Hi Ernie,
                              >
                              > Let me tell you that the therm "porosity defect",in foundry�s are very
                              > polemic...
                              >
                              > and it is becouse the couse for porosity in a foundry casting can be:
                              >
                              > - Air entrapment during the pouring
                              > - Gas coming from the mould
                              > - mould to cool (for metalic moulds)
                              > - gas in the liqued metal (nitrogen or Hydrogen), depend on the alloy
                              > - reaction betwen mould and metal.
                              > - contamination of the alloy in case of red brass, a very small amount of
                              > aluminum in the alloy cause undersurface porosity, the shape of the porus
                              > are large porosity like termits in the wood.
                              >
                              > So if you can give us more datails about the type of alloy, your tipe of
                              > furnace and a picture of the porus in the castng then we can have more
                              > information to help you.
                              >
                              > with the information you mentioned, I can recomend.
                              >
                              > 1.- be sure the tube (mold), are clean, and coat it with graphite coating.
                              > 2.- be sure the mouls is around 200 to 260 celsius degrees before pouring
                              > 3.- be sure you deoxidate the metal adding cooper phospurus just before
                              > pouring
                              > 4.- if is red brass, before deoxidate, you hace to de-gas the metal adding
                              > some product (LOGAS), that produce CO and CO2 boubles that take out the
                              > diseolved gas (hidrogen usualy) from the metal.
                              >
                              > if you can turn some degrees the mould to pur it and avoid the hit and
                              > splash of metal in the bottom of the mould it will help to avoid turbulende
                              > that can trao air in to the metal.
                              >
                              > be sure the temperature of the metal is good (qround 1180 - 1200 celsius
                              > degrees depend on the allloy. (50 celsius degrees over the liquidus
                              > temperature of the particular alloy), just before pour the mould.
                              >
                              > check this link.
                              >
                              >
                              > http://www.neon-john.com/Misc/ebooks/Foseco_Non-Ferrous_Foundrymans_Handbook_11thed.-J.Brown.pdf
                              >
                              > Hope it can help you.
                              >
                              > All the Best
                              >
                              > J.Luis
                              > Foundry consultant for Mexico and Latin America
                              >
                              > --- El mar 5-oct-10, ferroman1000 <ferroman1000@...<ferroman1000%40yahoo.com.au>>
                              > escribi�:
                              >
                              > De: ferroman1000 <ferroman1000@... <ferroman1000%40yahoo.com.au>>
                              > Asunto: [hobbicast] brass porosity
                              > A: hobbicast@yahoogroups.com <hobbicast%40yahoogroups.com>
                              > Fecha: martes, 5 de octubre de 2010, 23:25
                              >
                              >
                              >
                              > Hi, I am new to the group. My interest in casting is because I make model
                              > stationary steam engines. There is one problem that I have is constant
                              > porosity in brass. I use heavy walled steel pipe as a mould for round bar. I
                              > have tried every thing I can think of, such as preheating the mould, pouring
                              > at lower temps. The porosity is always just under the surface and I never
                              > have this prolem with aluminium. Any ideas?
                              > Cheers Ernie.
                              >
                              > [Non-text portions of this message have been removed]
                              >
                              >
                              >



                              --
                              Nick A

                              "You know what I wish? I wish that all the scum of the world had but a
                              single throat, and I had my hands about it..." Rorschach, 1975

                              "They that can give up essential liberty to obtain a little temporary safety
                              deserve neither liberty nor safety."- Benjamin Franklin, Historical Review
                              of Pennsylvania, 1759

                              "Suburbia is where the developer bulldozes out the trees, then names the
                              streets after them." Bill Vaughan

                              "The price of apathy towards public affairs is to be ruled by evil men."
                              Plato


                              [Non-text portions of this message have been removed]
                            • Kerri Duncan
                              J Luis- that pdf was an excellent toss-out- I have several answers I was looking for- thank you!  Still have more questions- but I am better equipped to
                              Message 14 of 16 , Oct 7, 2010
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                                J Luis- that pdf was an excellent toss-out- I have several answers I was looking for- thank you!  Still have more questions- but I am better equipped to troubleshoot!
                                 
                                Kerri



                                [Non-text portions of this message have been removed]
                              • Carlos Contreras
                                Guys,   Here is the link for FERROUS metals   http://www.neon-john.com/Misc/ebooks/Foseco_Ferrous_Foundrymans_Handbook-J.Brown.pdf   All teh best   ... De:
                                Message 15 of 16 , Oct 7, 2010
                                • 0 Attachment
                                  Guys,
                                   
                                  Here is the link for FERROUS metals
                                   
                                  http://www.neon-john.com/Misc/ebooks/Foseco_Ferrous_Foundrymans_Handbook-J.Brown.pdf

                                   
                                  All teh best
                                   

                                  --- El jue 7-oct-10, Nick Andrews <nickjandrews@...> escribió:


                                  De: Nick Andrews <nickjandrews@...>
                                  Asunto: Re: [hobbicast] brass porosity
                                  A: hobbicast@yahoogroups.com
                                  Fecha: jueves, 7 de octubre de 2010, 17:40


                                  I guess he doesn't have the third section on iron casting there, but a ton
                                  of other interesting books for sure!

                                  On Wed, Oct 6, 2010 at 9:51 PM, Carlos Contreras <maximo64@...>wrote:

                                  >
                                  >
                                  > Hi Ernie,
                                  >
                                  > Let me tell you that the therm "porosity defect",in foundry´s are very
                                  > polemic...
                                  >
                                  > and it is becouse the couse for porosity in a foundry casting can be:
                                  >
                                  > - Air entrapment during the pouring
                                  > - Gas coming from the mould
                                  > - mould to cool (for metalic moulds)
                                  > - gas in the liqued metal (nitrogen or Hydrogen), depend on the alloy
                                  > - reaction betwen mould and metal.
                                  > - contamination of the alloy in case of red brass, a very small amount of
                                  > aluminum in the alloy cause undersurface porosity, the shape of the porus
                                  > are large porosity like termits in the wood.
                                  >
                                  > So if you can give us more datails about the type of alloy, your tipe of
                                  > furnace and a picture of the porus in the castng then we can have more
                                  > information to help you.
                                  >
                                  > with the information you mentioned, I can recomend.
                                  >
                                  > 1.- be sure the tube (mold), are clean, and coat it with graphite coating.
                                  > 2.- be sure the mouls is around 200 to 260 celsius degrees before pouring
                                  > 3.- be sure you deoxidate the metal adding cooper phospurus just before
                                  > pouring
                                  > 4.- if is red brass, before deoxidate, you hace to de-gas the metal adding
                                  > some product (LOGAS), that produce CO and CO2 boubles that take out the
                                  > diseolved gas (hidrogen usualy) from the metal.
                                  >
                                  > if you can turn some degrees the mould to pur it and avoid the hit and
                                  > splash of metal in the bottom of the mould it will help to avoid turbulende
                                  > that can trao air in to the metal.
                                  >
                                  > be sure the temperature of the metal is good (qround 1180 - 1200 celsius
                                  > degrees depend on the allloy. (50 celsius degrees over the liquidus
                                  > temperature of the particular alloy), just before pour the mould.
                                  >
                                  > check this link.
                                  >
                                  >
                                  > http://www.neon-john.com/Misc/ebooks/Foseco_Non-Ferrous_Foundrymans_Handbook_11thed.-J.Brown.pdf
                                  >
                                  > Hope it can help you.
                                  >
                                  > All the Best
                                  >
                                  > J.Luis
                                  > Foundry consultant for Mexico and Latin America
                                  >
                                  > --- El mar 5-oct-10, ferroman1000 <ferroman1000@...<ferroman1000%40yahoo.com.au>>
                                  > escribió:
                                  >
                                  > De: ferroman1000 <ferroman1000@... <ferroman1000%40yahoo.com.au>>
                                  > Asunto: [hobbicast] brass porosity
                                  > A: hobbicast@yahoogroups.com <hobbicast%40yahoogroups.com>
                                  > Fecha: martes, 5 de octubre de 2010, 23:25
                                  >
                                  >
                                  >
                                  > Hi, I am new to the group. My interest in casting is because I make model
                                  > stationary steam engines. There is one problem that I have is constant
                                  > porosity in brass. I use heavy walled steel pipe as a mould for round bar. I
                                  > have tried every thing I can think of, such as preheating the mould, pouring
                                  > at lower temps. The porosity is always just under the surface and I never
                                  > have this prolem with aluminium. Any ideas?
                                  > Cheers Ernie.
                                  >
                                  > [Non-text portions of this message have been removed]
                                  >

                                  >



                                  --
                                  Nick A

                                  "You know what I wish?  I wish that all the scum of the world had but a
                                  single throat, and I had my hands about it..."  Rorschach, 1975

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                                  deserve neither liberty nor safety."- Benjamin Franklin, Historical Review
                                  of Pennsylvania, 1759

                                  "Suburbia is where the developer bulldozes out the trees, then names the
                                  streets after them." Bill Vaughan

                                  "The price of apathy towards public affairs is to be ruled by evil men."
                                  Plato


                                  [Non-text portions of this message have been removed]



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                                  [Non-text portions of this message have been removed]
                                • Carlos Contreras
                                  Thaks Kerri,   In Foudry we always will have questions, but there is a lot of writed information now (compare with 30ths lr 40ths, were no to much books was
                                  Message 16 of 16 , Oct 7, 2010
                                  • 0 Attachment
                                    Thaks Kerri,
                                     
                                    In Foudry we always will have questions, but there is a lot of writed information now (compare with 30ths lr 40ths, were no to much books was aviable).
                                     
                                    If you nee some specific, please let me know,.
                                     
                                    All the best.

                                    --- El vie 8-oct-10, Kerri Duncan <silverforgestudio@...> escribió:


                                    De: Kerri Duncan <silverforgestudio@...>
                                    Asunto: Re: [hobbicast] brass porosity
                                    A: hobbicast@yahoogroups.com
                                    Fecha: viernes, 8 de octubre de 2010, 0:41


                                     



                                    J Luis- that pdf was an excellent toss-out- I have several answers I was looking for- thank you!  Still have more questions- but I am better equipped to troubleshoot!
                                     
                                    Kerri

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