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Lost foam casting

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  • Andrew Werby
    1f. Re: local members Jeshua Lacock jeshua@OpenOSX.com jeshua_lacock wrote: One thing you might be able to do before you get your green sand is a lost foam
    Message 1 of 26 , May 22, 2009
      1f. Re: local members
      "Jeshua Lacock" jeshua@... jeshua_lacock wrote:


      One thing you might be able to do before you get your green sand is a
      lost foam shell casting.

      Just make your pattern out of foam, with sprue, gate, riser, vents,
      etc., then coat it with a few layers of plaster of paris (usually 50%
      plaster of paris, 50% sand to improve the refractory properties), bake
      it at 250F to drive off all of the moisture, put it in a box or flask
      of some sort, and pour in dry (regular home depot) sand. Vibrate/shake
      the flask as it is filling to evenly pack the sand.

      [Have you actually done this yourself, Joshua, or is this the result of
      reading about this and putting things together that you've read?]

      It is possible to use this method to actually achieve superior results
      to green sand. Note that the majority of engine blocks casted today use
      a variation of this method which require minimal machining. You can
      achieve 0.001" out of the shell.

      [This sounds dangerous to me. This is not how engine blocks are made,
      although foam patterns are sometimes used. The lost-foam method works
      okay if you just pack the foam pattern in loose sand, because any gases
      generated will be able to vent easily through the sand. But when you
      start building up layers of plaster around the foam, then you've blocked
      off all the routes the gas has to escape through, except by coming up
      through the molten metal. I've heard of people getting away with a thin
      coating of drywall mud over the foam, but several layers of plaster of
      Paris would be much less permeable, and would contribute gases of their
      own..


      It is possible to pour metal into molds composed of plaster of Paris and
      sand, but you can't randomly combine some elements of one casting
      technique with some from another and expect it all to work safely. 250F
      is not enough to drive off the chemically-bonded water from plaster
      (although it would collapse your foam); that takes about 1000F (which is
      what you'd get from your molten metal, all at once). What you're
      creating here is essentially a volcano - I wouldn't want to be around
      when it goes off...]

      Andrew Werby
      www.unitedartworks.com
    • Jeshua Lacock
      ... First of all I said a variation of this method was used. And you are making this statement based on what? From:
      Message 2 of 26 , May 22, 2009
        On May 22, 2009, at 12:16 PM, Andrew Werby wrote:

        > [This sounds dangerous to me. This is not how engine blocks are made,
        > although foam patterns are sometimes used.


        First of all I said a variation of this method was used.

        And you are making this statement based on what?

        From:

        http://en.wikipedia.org/wiki/Lost-foam_casting

        "Next, the foam cluster is coated with ceramic investment, either by
        dipping, spraying or pouring."

        Complete with citations 6 and 7:

        "Lost-foam casting was invented in 1964 by M.C. Flemmings.[6] Public
        recognition of the benefits of LFC was made by General Motors in the
        mid 1980s when it announced its new car line, Saturn, would utilize
        LFC for production of all ENGINE BLOCKS, cylinder heads, crankshafts,
        differential carriers, and transmission cases.[7]" (emphasis provided)


        And today, it is a FACT that more than 50% of engine blocks produced
        are done with a similar method. Check for yourself. I have read this
        fact from several reliable sources before when I was researching shell
        casting several years ago, so I cannot site specific citations, but
        you can verify this fact yourself.

        > The lost-foam method works
        > okay if you just pack the foam pattern in loose sand, because any
        > gases
        > generated will be able to vent easily through the sand. But when you
        > start building up layers of plaster around the foam, then you've
        > blocked
        > off all the routes the gas has to escape through, except by coming up
        > through the molten metal.

        I also stated specifically to add VENTS to the mold.

        Additionally, because the plaster of paris shell is sufficiently dry,
        there is a minimal amount of gas. The only real gassing is from the
        foam which comes in the form of a flame coming out of the sprue, riser
        and/or vents. This is the case with ANY lost foam casting - green sand
        or shell.

        > I've heard of people getting away with a thin
        > coating of drywall mud over the foam, but several layers of plaster of
        > Paris would be much less permeable, and would contribute gases of
        > their
        > own..

        Drywall mud is essentially the same as plaster of paris.

        > It is possible to pour metal into molds composed of plaster of Paris
        > and
        > sand, but you can't randomly combine some elements of one casting
        > technique with some from another and expect it all to work safely.
        > 250F
        > is not enough to drive off the chemically-bonded water from plaster

        In my experience, 250F for about an hour drives of practically all of
        the water, and is much drier than green sand.

        In fact, my dad who lives in New Mexico refuses to even bake out his
        shells. He just coats the foam with plaster and lets it sit in the
        desert sun for about an hour.

        Both of us have never experienced dangerous gases, let alone a volcano.

        > (although it would collapse your foam);

        No - at 250 the foam does not collapse. You have to heat to over 400F
        for it to start melting the foam.

        Sounds like you have no experience with this.

        > that takes about 1000F (which is
        > what you'd get from your molten metal, all at once). What you're
        > creating here is essentially a volcano - I wouldn't want to be around
        > when it goes off...]

        The first time we ever made green sand, (before the age of the
        Internet), we had very little information available on how to make
        green sand, and that was the scariest pour we ever made. It was
        bubbling, cracking and hissing violently - this is not at all the case
        using plaster of paris shells that I have used.


        Sincerely,

        Jeshua Lacock, Owner
        <http://OpenOSX.com>
        phone: 877.240.1364
      • Dave
        Jeshua, Thanks for your input on this group. Do you use lost foam for cast iron too? I would think those high temps would burn the foam out very quick? I too
        Message 3 of 26 , May 23, 2009
          Jeshua,

          Thanks for your input on this group. Do you use lost foam for cast iron too? I would think those high temps would burn the foam out very quick?

          I too have never had a volcano using lost foam...lots of smoke and flames though. As you said, proper venting is the key. How thick do you make the plaster, sand coating?

          It is important that moisture not get trapped under molten metal with no place to go...Like many people have told us about the dangers of pouring on concrete, etc.. I had one casting session that I had a little explosion...I was pouring in a day when it was "misting" almost like a fog. Well, the pour was fine, but I went to pour my excess metal into my cast iron muffin pan and there was some moisture in it. I heard a little pop and had drops of metal thrown up over my siding the whole way up to the gutter on the garage. That made me remember to heat up my "ingot" pan in the future.

          Dave D
          http://metalshop.homestead.com


          >
        • Bruce Hoover
          Hello I have some experience with lost foam castings. You can see the pics on my website at www.wtxrcdog.com I just spray on three light coats of dry wall
          Message 4 of 26 , May 23, 2009
            Hello I have some experience with lost foam castings. You can see the
            pics on my website at www.wtxrcdog.com I just spray on three light
            coats of dry wall mud that has been thinned down until it is like milk.
            Let them dry between coats and place the mold in sand and pour. The
            plaster is permeable to gases released by the foam. I have also used
            masking tape to coat the mold whitch turns to charcoal when the metal
            hits it keeping the sand from sticking to the part.. there are examples
            on my site. <www.wtxrcdog.com>

            Good Luck
            Bruce
          • warren hughes
            Bruce your site dose ot come up ? Waren Hughes ... From: Bruce Hoover Subject: [hobbicast] Re: Lost foam casting To:
            Message 5 of 26 , May 23, 2009
              Bruce your site dose ot come up ? Waren Hughes

              --- On Sat, 5/23/09, Bruce Hoover <wtxrcdog@...> wrote:


              From: Bruce Hoover <wtxrcdog@...>
              Subject: [hobbicast] Re: Lost foam casting
              To: hobbicast@yahoogroups.com
              Date: Saturday, May 23, 2009, 9:37 AM








              Hello I have some experience with lost foam castings. You can see the
              pics on my website at www.wtxrcdog. com I just spray on three light
              coats of dry wall mud that has been thinned down until it is like milk.
              Let them dry between coats and place the mold in sand and pour. The
              plaster is permeable to gases released by the foam. I have also used
              masking tape to coat the mold whitch turns to charcoal when the metal
              hits it keeping the sand from sticking to the part.. there are examples
              on my site. <www.wtxrcdog. com>

              Good Luck
              Bruce



















              [Non-text portions of this message have been removed]
            • Jeshua Lacock
              ... I have but not with Plaster of Paris. Plaster of paris is useless at those temperatures (it melts!). For up to 3100F, hydrolyzed ethyl silicate is used as
              Message 6 of 26 , May 23, 2009
                On May 23, 2009, at 7:39 AM, Dave wrote:

                > Thanks for your input on this group. Do you use lost foam for cast
                > iron too?

                I have but not with Plaster of Paris. Plaster of paris is useless at
                those temperatures (it melts!).

                For up to 3100F, hydrolyzed ethyl silicate is used as a binder for a
                higher rated refractory than sand, such aluminum oxide and/or zircon.
                A small amount of ammonium carbonate solution for the gelling agent is
                added, usually around 7.5 % .

                Often for higher temperature castings (eg ferrous), a "precoat" layer
                of premium refractory is used for the surface layer, followed by
                "backup" layers that can use courser and lower rated (cheaper)
                materials.

                > I would think those high temps would burn the foam out very quick?

                Yes of course! Foam is no match for molten Iron!

                Moohahaha!

                <grin>

                > I too have never had a volcano using lost foam...lots of smoke and
                > flames though. As you said, proper venting is the key. How thick do
                > you make the plaster, sand coating?


                It depends on the part. Small parts 1 coating seems fine, lager parts
                I use up to 3.


                Best,

                Jeshua Lacock, Owner
                <http://OpenOSX.com>
                phone: 877.240.1364
              • Jeshua Lacock
                ... I would just add that there are also several tricks to increase the permeability if needed. Foaming agents can create a series of interconnected
                Message 7 of 26 , May 23, 2009
                  On May 23, 2009, at 9:37 AM, Bruce Hoover wrote:

                  > The plaster is permeable to gases released by the foam.


                  I would just add that there are also several tricks to increase the
                  permeability if needed.

                  Foaming agents can create a series of interconnected microscopic air
                  bubbles. For us hobbyists, a foaming agent is simply a few drops of
                  dish soap. Just mix as usual, then add a small amount of dish soap,
                  let it stand for about half a minute and then mix with a drill with a
                  rubber disc near the bottom until it is well mixed. Then raise the
                  disc to create a vortex which is what will create the foam. Your mix
                  can increase up to 70% volume in about a minute. To create very fine
                  bubbles, you can raise and lower the disc to control the size. About
                  50% increase in volume tends to be ideal.

                  Many commercial investments contain a foaming agent built-in.

                  Other tricks include additives such as sawdust (that burns out leaving
                  a permeable structure), seacoal (crushed coke), pearlite, grog,
                  string and even paper.

                  Note that I learned this from "Metal Casting Made Simple" by C.W. Ammen.


                  Best,

                  Jeshua Lacock, Owner
                  <http://OpenOSX.com>
                  phone: 877.240.1364
                • Bruce Hoover
                  Sorry maybe there is a space in my link try this www.wtxrcdog.com This one works. Some of my early lost foam castings were dipped in dry wall mud . Bruce
                  Message 8 of 26 , May 24, 2009
                    Sorry maybe there is a space in my link try this www.wtxrcdog.com
                    This one works. Some of my early lost foam castings were dipped in dry
                    wall mud .

                    Bruce
                  • Lyle
                    I ve never found the need to coat lost foam in anything. I just ram sand around it and pour. LL
                    Message 9 of 26 , May 24, 2009
                      I've never found the need to coat lost foam in anything. I just ram sand around it and pour.
                      LL

                      --- In hobbicast@yahoogroups.com, Bruce Hoover <wtxrcdog@...> wrote:
                      >
                      > Sorry maybe there is a space in my link try this www.wtxrcdog.com
                      > This one works. Some of my early lost foam castings were dipped in dry
                      > wall mud .
                      >
                      > Bruce
                      >
                    • Jeshua Lacock
                      ... While I don t doubt that, I think with just about anything there are pros and cons. In my experience, the primary advantage of investment shell is you can
                      Message 10 of 26 , May 24, 2009
                        On May 24, 2009, at 9:34 AM, Lyle wrote:

                        > I've never found the need to coat lost foam in anything. I just ram
                        > sand around it and pour.


                        While I don't doubt that, I think with just about anything there are
                        pros and cons.

                        In my experience, the primary advantage of investment shell is you can
                        achieve higher dimensional accuracy compared to green sand. I have
                        found that when ramming sand around a foam pattern, it is VERY easy to
                        distort the foam. In fact, seems like it is nearly impossible to not
                        distort the foam from ramming.

                        With a shell casting, the sand is filled and packed by vibration, and
                        is completely uniform and will not cause even slight distortion to the
                        pattern.

                        I think another primary advantage is the ability to have the premium
                        investment just where the metal comes in contact with the mold, backed
                        by cheap, ordinary "home depot" sand.

                        Which I think brings us back to the original intent of the beginning
                        of this thread.

                        But this becomes particularly useful for higher temperature castings,
                        as investment for 3,000F+ gets pretty spendy, and I would not want to
                        fill a whole flask with them. A thin shell of high grade material
                        backed with cheap sand is much preferable, that is also reusable an
                        infinite number of times...


                        Best,

                        Jeshua Lacock, Owner
                        <http://OpenOSX.com>
                        phone: 877.240.1364
                      • Lyle
                        Ok now you aroused my curiosity, what are you doing that s requiring that degree of accuracy and pouring over 3000 degrees? Everyting I do that Hot (stainless
                        Message 11 of 26 , May 24, 2009
                          Ok now you aroused my curiosity, what are you doing that's requiring that degree of accuracy and pouring over 3000 degrees? Everyting I do that Hot (stainless etc) I job out to an investment casting place.

                          LL

                          In hobbicast@yahoogroups.com, Jeshua Lacock <jeshua@...> wrote:
                          >
                          >
                          > On May 24, 2009, at 9:34 AM, Lyle wrote:
                          >
                          > > I've never found the need to coat lost foam in anything. I just ram
                          > > sand around it and pour.
                          >
                          >
                          > While I don't doubt that, I think with just about anything there are
                          > pros and cons.
                          >
                          > In my experience, the primary advantage of investment shell is you can
                          > achieve higher dimensional accuracy compared to green sand. I have
                          > found that when ramming sand around a foam pattern, it is VERY easy to
                          > distort the foam. In fact, seems like it is nearly impossible to not
                          > distort the foam from ramming.
                          >
                          > With a shell casting, the sand is filled and packed by vibration, and
                          > is completely uniform and will not cause even slight distortion to the
                          > pattern.
                          >
                          > I think another primary advantage is the ability to have the premium
                          > investment just where the metal comes in contact with the mold, backed
                          > by cheap, ordinary "home depot" sand.
                          >
                          > Which I think brings us back to the original intent of the beginning
                          > of this thread.
                          >
                          > But this becomes particularly useful for higher temperature castings,
                          > as investment for 3,000F+ gets pretty spendy, and I would not want to
                          > fill a whole flask with them. A thin shell of high grade material
                          > backed with cheap sand is much preferable, that is also reusable an
                          > infinite number of times...
                          >
                          >
                          > Best,
                          >
                          > Jeshua Lacock, Owner
                          > <http://OpenOSX.com>
                          > phone: 877.240.1364
                          >
                        • Jeshua Lacock
                          ... Several projects, a turbine for one. Best, Jeshua Lacock, Owner phone: 877.240.1364
                          Message 12 of 26 , May 24, 2009
                            On May 24, 2009, at 5:40 PM, Lyle wrote:

                            > Ok now you aroused my curiosity, what are you doing that's requiring
                            > that degree of accuracy and pouring over 3000 degrees? Everyting I
                            > do that Hot (stainless etc) I job out to an investment casting place.


                            Several projects, a turbine for one.


                            Best,

                            Jeshua Lacock, Owner
                            <http://OpenOSX.com>
                            phone: 877.240.1364
                          • Lyle
                            So how d you make the foam pattern? LL
                            Message 13 of 26 , May 24, 2009
                              So how'd you make the foam pattern?
                              LL
                              --- In hobbicast@yahoogroups.com, Jeshua Lacock <jeshua@...> wrote:
                              >
                              >
                              > On May 24, 2009, at 5:40 PM, Lyle wrote:
                              >
                              > > Ok now you aroused my curiosity, what are you doing that's requiring
                              > > that degree of accuracy and pouring over 3000 degrees? Everyting I
                              > > do that Hot (stainless etc) I job out to an investment casting place.
                              >
                              >
                              > Several projects, a turbine for one.
                              >
                              >
                              > Best,
                              >
                              > Jeshua Lacock, Owner
                              > <http://OpenOSX.com>
                              > phone: 877.240.1364
                              >
                            • Jeshua Lacock
                              ... My friend s CNC machine. Working on one of my own too - another project requiring dimensional accurate castings. I found that ramming sand around foam can
                              Message 14 of 26 , May 24, 2009
                                On May 24, 2009, at 8:12 PM, Lyle wrote:

                                > So how'd you make the foam pattern?

                                My friend's CNC machine. Working on one of my own too - another
                                project requiring dimensional accurate castings.

                                I found that ramming sand around foam can easy distort the pattern by
                                1/4" or more...


                                Best,

                                Jeshua Lacock, Owner
                                <http://OpenOSX.com>
                                phone: 877.240.1364
                              • postello@msu.edu
                                Foam is not rigid.  I had similar problems trying to use foam as a traditional pattern using greensand. The original technique used by the person who invented
                                Message 15 of 26 , May 25, 2009
                                  Foam is not rigid.  I had similar problems trying to use foam as a
                                  traditional pattern using greensand. The original technique used by
                                  the person who invented lost foam was different.  He used greensand,
                                  with all of the pattern and sprues and such done in foam, and rammed
                                  in greensand as a "one piece" mold. This is a little more stable,
                                  but the foam still wiggles or compresses some. The Saturn engine
                                  blocks have foam patterns that are invested in some sort of ceramic to
                                  hold the shape, then packed in loose sand before pouring. That
                                  technique gives more predictable dimensions, in theory.   I just never
                                  got it to work, personally.  Since I'm fooling around with sculpture
                                  castings, the dimensions usually are not that critical.
                                  I recently found a cornstick pan at an antique shop that casts
                                  fish-shaped cornsticks, or ingots. They said it was a Eddie Bauer
                                  product, if anyone wants to try to find another on eBay. It makes an
                                  unusual permanent ingot mold.  Dan P.

                                  > So how'd you make the foam pattern?
                                  > LL
                                  > --- In hobbicast@yahoogroups.com, Jeshua Lacock <jeshua@...> wrote:
                                  >>
                                  >>
                                  >> On May 24, 2009, at 5:40 PM, Lyle wrote:
                                  >>
                                  >> > Ok now you aroused my curiosity, what are you doing that's
                                  requiring
                                  >> > that degree of accuracy and pouring over 3000 degrees? Everyting
                                  I
                                  >> > do that Hot (stainless etc) I job out to an investment casting
                                  place.
                                  >>
                                  >>
                                  >> Several projects, a turbine for one.
                                  >>
                                  >>
                                  >> Best,
                                  >>
                                  >> Jeshua Lacock, Owner
                                  >> <http://OpenOSX.com>
                                  >> phone: 877.240.1364
                                  >>
                                  >
                                  >
                                  >

                                  [Non-text portions of this message have been removed]
                                • Ron Thompson
                                  There s your problem. Don t ram it, use loose sand. Put about 2 inches in the bottom of your flask/box/bucket and place your foam. Pour sand in around it,
                                  Message 16 of 26 , May 25, 2009
                                    There's your problem. Don't ram it, use loose sand. Put about 2 inches
                                    in the bottom of your flask/box/bucket and place your foam. Pour sand in
                                    around it, bumping the flask every now and then to settle the sand. When
                                    the sand is near the top of the sprue, you are ready to pour.
                                    For the newbies reading this, keep your head away from the area over the
                                    sprue. The smoke and fumes will flash into flame. Hold your breath as
                                    you pour. Don't breath the fumes. Some people put a fan to their back,
                                    blowing the fumes away from them.

                                    I use this method often to make ingots or to make stock for the milling
                                    machine. I just use a scrap chunk of foam embedded in the sand to make
                                    aluminum "planks."

                                    Jeshua Lacock wrote:
                                    >
                                    >
                                    >
                                    >
                                    > On May 24, 2009, at 8:12 PM, Lyle wrote:
                                    >
                                    > > So how'd you make the foam pattern?
                                    >
                                    > My friend's CNC machine. Working on one of my own too - another
                                    > project requiring dimensional accurate castings.
                                    >
                                    > I found that ramming sand around foam can easy distort the pattern by
                                    > 1/4" or more...
                                    >
                                    > Best,
                                    >
                                    > Jeshua Lacock, Owner
                                    > <http://OpenOSX.com <http://OpenOSX.com>>
                                    > phone: 877.240.1364
                                    >
                                    >

                                    --


                                    Ron Thompson
                                    Riding my '07 XL883C Sportster
                                    On the Beautiful Florida Space Coast,
                                    right beside the Kennedy Space Center,
                                    USA

                                    http://www.plansandprojects.com
                                    My hobby pages are here:
                                    http://www.plansandprojects.com/My%20Machines/

                                    Visit the castinghobby FAQ:
                                    http://castinghobbyfaq.bareboogerhost.com/

                                    Add yourself to the member map here:
                                    http://www.frappr.com/castinghobby

                                    Want to have some fun? The next time you're at McDonald's, wait until
                                    the kid has your change ready and then say "Wait, I've got the two cents."
                                    -Ron Thompson
                                  • Dave
                                    Are you asking Jeshua...or just making a foam pattern in general? foam can be cut with a router, hot wire, hack saw, utility or exacto knife, etc. If I am
                                    Message 17 of 26 , May 25, 2009
                                      Are you asking Jeshua...or just making a foam pattern in general?

                                      foam can be cut with a router, hot wire, hack saw, utility or exacto knife, etc. If I am doing something artistic, I usually like a rough finish so I use a drywall saw. Here is a link to a page I sent out to my e-zine members a while ago that shows that:
                                      http://metalshop.homestead.com/EZine.html

                                      Here is a link to my hot wire foam cutter too:
                                      http://metalshop.homestead.com/hotwirefoamcutter.html

                                      Here is a link to a video of a lost foam pour I took:
                                      http://www.youtube.com/watch?v=OLt5xUv7a8s

                                      Hope that helps.

                                      One more thing...If you are using the pink or blue sheet foam, you can use contact glue made for foam to glue the sheets together to make a thicker piece.

                                      If you need to find foam, look for roofing jobs on commercial buildings. I once found a whole dumpster full of large sheets of 4 inch foam.

                                      Dave D
                                      http://metalshop.homestead.com

                                      PS Have a great holiday (US)


                                      --- In hobbicast@yahoogroups.com, "Lyle" <creepinogie@...> wrote:
                                      >
                                      > So how'd you make the foam pattern?
                                      > LL
                                      > --- In hobbicast@yahoogroups.com, Jeshua Lacock <jeshua@> wrote:
                                      > >
                                      > >
                                      > > On May 24, 2009, at 5:40 PM, Lyle wrote:
                                      > >
                                      > > > Ok now you aroused my curiosity, what are you doing that's requiring
                                      > > > that degree of accuracy and pouring over 3000 degrees? Everyting I
                                      > > > do that Hot (stainless etc) I job out to an investment casting place.
                                      > >
                                      > >
                                      > > Several projects, a turbine for one.
                                      > >
                                      > >
                                      > > Best,
                                      > >
                                      > > Jeshua Lacock, Owner
                                      > > <http://OpenOSX.com>
                                      > > phone: 877.240.1364
                                      > >
                                      >
                                    • Lyle
                                      I use a hot wire for mine. A guy in this list Mr. Grantham showed me his set up when I visited him and I took some of his ideas. But I d never heard of a
                                      Message 18 of 26 , May 25, 2009
                                        I use a hot wire for mine. A guy in this list Mr. Grantham showed me his set up when I visited him and I took some of his ideas. But I'd never heard of a turbine being made from foam so that's why I asked. 99.9% of my castings are still sandcast with good old wood, plastic, or metal patterns though.
                                        LL

                                        --- In hobbicast@yahoogroups.com, "Dave" <drescher3@...> wrote:
                                        >
                                        > Are you asking Jeshua...or just making a foam pattern in general?
                                        >
                                        > foam can be cut with a router, hot wire, hack saw, utility or exacto knife, etc. If I am doing something artistic, I usually like a rough finish so I use a drywall saw. Here is a link to a page I sent out to my e-zine members a while ago that shows that:
                                        > http://metalshop.homestead.com/EZine.html
                                        >
                                        > Here is a link to my hot wire foam cutter too:
                                        > http://metalshop.homestead.com/hotwirefoamcutter.html
                                        >
                                        > Here is a link to a video of a lost foam pour I took:
                                        > http://www.youtube.com/watch?v=OLt5xUv7a8s
                                        >
                                        > Hope that helps.
                                        >
                                        > One more thing...If you are using the pink or blue sheet foam, you can use contact glue made for foam to glue the sheets together to make a thicker piece.
                                        >
                                        > If you need to find foam, look for roofing jobs on commercial buildings. I once found a whole dumpster full of large sheets of 4 inch foam.
                                        >
                                        > Dave D
                                        > http://metalshop.homestead.com
                                        >
                                        > PS Have a great holiday (US)
                                        >
                                        >
                                        > --- In hobbicast@yahoogroups.com, "Lyle" <creepinogie@> wrote:
                                        > >
                                        > > So how'd you make the foam pattern?
                                        > > LL
                                        > > --- In hobbicast@yahoogroups.com, Jeshua Lacock <jeshua@> wrote:
                                        > > >
                                        > > >
                                        > > > On May 24, 2009, at 5:40 PM, Lyle wrote:
                                        > > >
                                        > > > > Ok now you aroused my curiosity, what are you doing that's requiring
                                        > > > > that degree of accuracy and pouring over 3000 degrees? Everyting I
                                        > > > > do that Hot (stainless etc) I job out to an investment casting place.
                                        > > >
                                        > > >
                                        > > > Several projects, a turbine for one.
                                        > > >
                                        > > >
                                        > > > Best,
                                        > > >
                                        > > > Jeshua Lacock, Owner
                                        > > > <http://OpenOSX.com>
                                        > > > phone: 877.240.1364
                                        > > >
                                        > >
                                        >
                                      • postello@msu.edu
                                        They do turbine blades locally as investment cast lost wax. ... me ... asked. ... plastic, ... 4 ... requiring ... Everyting I ... casting place. ... [1]
                                        Message 19 of 26 , May 25, 2009
                                          They do turbine blades locally as investment cast lost wax.

                                          > I use a hot wire for mine. A guy in this list Mr. Grantham showed
                                          me
                                          > his set up when I visited him and I took some of his ideas. But I'd

                                          > never heard of a turbine being made from foam so that's why I
                                          asked.
                                          > 99.9% of my castings are still sandcast with good old wood,
                                          plastic,
                                          > or metal patterns though.
                                          > LL
                                          >
                                          > --- In hobbicast@yahoogroups.com, "Dave" <drescher3@...> wrote:
                                          >>
                                          >> Are you asking Jeshua...or just making a foam pattern in general?
                                          >>
                                          >> foam can be cut with a router, hot wire, hack saw, utility or
                                          >> exacto knife, etc. If I am doing something artistic, I usually
                                          >> like a rough finish so I use a drywall saw. Here is a link to a
                                          >> page I sent out to my e-zine members a while ago that shows that:
                                          >> http://metalshop.homestead.com/EZine.html[1]
                                          >>
                                          >> Here is a link to my hot wire foam cutter too:
                                          >> http://metalshop.homestead.com/hotwirefoamcutter.html[2]
                                          >>
                                          >> Here is a link to a video of a lost foam pour I took:
                                          >> http://www.youtube.com/watch?v=OLt5xUv7a8s[3]
                                          >>
                                          >> Hope that helps.
                                          >>
                                          >> One more thing...If you are using the pink or blue sheet foam, you

                                          >> can use contact glue made for foam to glue the sheets together to
                                          >> make a thicker piece.
                                          >>
                                          >> If you need to find foam, look for roofing jobs on commercial
                                          >> buildings. I once found a whole dumpster full of large sheets of
                                          4
                                          >> inch foam.
                                          >>
                                          >> Dave D
                                          >> http://metalshop.homestead.com[4]
                                          >>
                                          >> PS Have a great holiday (US)
                                          >>
                                          >>
                                          >> --- In hobbicast@yahoogroups.com, "Lyle" <creepinogie@> wrote:
                                          >> >
                                          >> > So how'd you make the foam pattern?
                                          >> > LL
                                          >> > --- In hobbicast@yahoogroups.com, Jeshua Lacock <jeshua@> wrote:
                                          >> > >
                                          >> > >
                                          >> > > On May 24, 2009, at 5:40 PM, Lyle wrote:
                                          >> > >
                                          >> > > > Ok now you aroused my curiosity, what are you doing that's
                                          requiring
                                          >> > > > that degree of accuracy and pouring over 3000 degrees?
                                          Everyting I
                                          >> > > > do that Hot (stainless etc) I job out to an investment
                                          casting place.
                                          >> > >
                                          >> > >
                                          >> > > Several projects, a turbine for one.
                                          >> > >
                                          >> > >
                                          >> > > Best,
                                          >> > >
                                          >> > > Jeshua Lacock, Owner
                                          >> > > <http://OpenOSX.com[5]>
                                          >> > > phone: 877.240.1364
                                          >> > >
                                          >> >
                                          >>
                                          >
                                          >
                                          >


                                          Links:
                                          ------
                                          [1] http://metalshop.homestead.com/EZine.html
                                          [2] http://metalshop.homestead.com/hotwirefoamcutter.html
                                          [3] http://www.youtube.com/watch?v=OLt5xUv7a8s
                                          [4] http://metalshop.homestead.com
                                          [5] http://OpenOSX.com
                                        • postello@msu.edu
                                          This works OK for simple shapes. It does not for the rings or pieces with undercuts. ... inches ... sand in ... When ... over the ... as ... back, ... milling
                                          Message 20 of 26 , May 25, 2009
                                            This works OK for simple shapes. It does not for the rings or pieces
                                            with undercuts.

                                            > There's your problem. Don't ram it, use loose sand. Put about 2
                                            inches
                                            > in the bottom of your flask/box/bucket and place your foam. Pour
                                            sand in
                                            > around it, bumping the flask every now and then to settle the sand.
                                            When
                                            > the sand is near the top of the sprue, you are ready to pour.
                                            > For the newbies reading this, keep your head away from the area
                                            over the
                                            > sprue. The smoke and fumes will flash into flame. Hold your breath
                                            as
                                            > you pour. Don't breath the fumes. Some people put a fan to their
                                            back,
                                            > blowing the fumes away from them.
                                            >
                                            > I use this method often to make ingots or to make stock for the
                                            milling
                                            > machine. I just use a scrap chunk of foam embedded in the sand to
                                            make
                                            > aluminum "planks."
                                            >
                                            > Jeshua Lacock wrote:
                                            >>
                                            >>
                                            >>
                                            >>
                                            >> On May 24, 2009, at 8:12 PM, Lyle wrote:
                                            >>
                                            >>   > So how'd you make the foam pattern?
                                            >>
                                            >> My friend's CNC machine. Working on one of my own too - another
                                            >> project requiring dimensional accurate castings.
                                            >>
                                            >> I found that ramming sand around foam can easy distort the pattern
                                            by
                                            >> 1/4" or more...
                                            >>
                                            >> Best,
                                            >>
                                            >> Jeshua Lacock, Owner
                                            >> <http://OpenOSX.com <http://OpenOSX.com>>
                                            >> phone: 877.240.1364
                                            >>
                                            >>
                                            >
                                            > --
                                            >
                                            >
                                            > Ron Thompson
                                            > Riding my '07 XL883C Sportster
                                            > On the Beautiful Florida Space Coast,
                                            > right beside the Kennedy Space Center,
                                            > USA
                                            >
                                            > http://www.plansandprojects.com
                                            > My hobby pages are here:
                                            > http://www.plansandprojects.com/My%20Machines/
                                            >
                                            > Visit the castinghobby FAQ:
                                            > http://castinghobbyfaq.bareboogerhost.com/
                                            >
                                            > Add yourself to the member map here:
                                            > http://www.frappr.com/castinghobby
                                            >
                                            > Want to have some fun? The next time you're at McDonald's, wait
                                            until
                                            > the kid has your change ready and then say "Wait, I've got the two
                                            cents."
                                            > -Ron Thompson
                                            >
                                          • Lyle
                                            I ve jobbed stuff out to a place in Minneapolis that does them in ceramic shell lost wax as well. The tolerance is really good. The problem I have with them is
                                            Message 21 of 26 , May 25, 2009
                                              I've jobbed stuff out to a place in Minneapolis that does them in ceramic shell lost wax as well. The tolerance is really good. The problem I have with them is they want an order of about a 1000 parts before they deal with you, unlike most alum foundrys. It was sort of interesting when I toured the place, they had their little torches for attaching the parts to the sprue powered by hydrogen that they made from water right there. The guy had started the place a few decades ago by converting a grease gun into a wax injector. Needless to say, the place a really grown. They would do the burnout at over 1000 degres and while the ceramic was still warm pour in the steel. The whole mold would glow and you could literally watch the glow rise as the metal rose in the mold.

                                              On another matter, I spend most the day yesterday machining a cast valve cover mill and drill fixture for some valve covers I make just to figure out I need to reinforce it so the part won't chatter, back to the pattern shop for some revisions and then a recast......I considered lost foam for the fixture but it's almost as easy to cut everything out of wood and paint with varnish to make a reusable pattern.
                                              LL

                                              --- In hobbicast@yahoogroups.com, postello@... wrote:
                                              >
                                              > They do turbine blades locally as investment cast lost wax.
                                              >
                                              > > I use a hot wire for mine. A guy in this list Mr. Grantham showed
                                              > me
                                              > > his set up when I visited him and I took some of his ideas. But I'd
                                              >
                                              > > never heard of a turbine being made from foam so that's why I
                                              > asked.
                                              > > 99.9% of my castings are still sandcast with good old wood,
                                              > plastic,
                                              > > or metal patterns though.
                                              > > LL
                                              > >
                                              > > --- In hobbicast@yahoogroups.com, "Dave" <drescher3@> wrote:
                                              > >>
                                              > >> Are you asking Jeshua...or just making a foam pattern in general?
                                              > >>
                                              > >> foam can be cut with a router, hot wire, hack saw, utility or
                                              > >> exacto knife, etc. If I am doing something artistic, I usually
                                              > >> like a rough finish so I use a drywall saw. Here is a link to a
                                              > >> page I sent out to my e-zine members a while ago that shows that:
                                              > >> http://metalshop.homestead.com/EZine.html[1]
                                              > >>
                                              > >> Here is a link to my hot wire foam cutter too:
                                              > >> http://metalshop.homestead.com/hotwirefoamcutter.html[2]
                                              > >>
                                              > >> Here is a link to a video of a lost foam pour I took:
                                              > >> http://www.youtube.com/watch?v=OLt5xUv7a8s[3]
                                              > >>
                                              > >> Hope that helps.
                                              > >>
                                              > >> One more thing...If you are using the pink or blue sheet foam, you
                                              >
                                              > >> can use contact glue made for foam to glue the sheets together to
                                              > >> make a thicker piece.
                                              > >>
                                              > >> If you need to find foam, look for roofing jobs on commercial
                                              > >> buildings. I once found a whole dumpster full of large sheets of
                                              > 4
                                              > >> inch foam.
                                              > >>
                                              > >> Dave D
                                              > >> http://metalshop.homestead.com[4]
                                              > >>
                                              > >> PS Have a great holiday (US)
                                              > >>
                                              > >>
                                              > >> --- In hobbicast@yahoogroups.com, "Lyle" <creepinogie@> wrote:
                                              > >> >
                                              > >> > So how'd you make the foam pattern?
                                              > >> > LL
                                              > >> > --- In hobbicast@yahoogroups.com, Jeshua Lacock <jeshua@> wrote:
                                              > >> > >
                                              > >> > >
                                              > >> > > On May 24, 2009, at 5:40 PM, Lyle wrote:
                                              > >> > >
                                              > >> > > > Ok now you aroused my curiosity, what are you doing that's
                                              > requiring
                                              > >> > > > that degree of accuracy and pouring over 3000 degrees?
                                              > Everyting I
                                              > >> > > > do that Hot (stainless etc) I job out to an investment
                                              > casting place.
                                              > >> > >
                                              > >> > >
                                              > >> > > Several projects, a turbine for one.
                                              > >> > >
                                              > >> > >
                                              > >> > > Best,
                                              > >> > >
                                              > >> > > Jeshua Lacock, Owner
                                              > >> > > <http://OpenOSX.com[5]>
                                              > >> > > phone: 877.240.1364
                                              > >> > >
                                              > >> >
                                              > >>
                                              > >
                                              > >
                                              > >
                                              >
                                              >
                                              > Links:
                                              > ------
                                              > [1] http://metalshop.homestead.com/EZine.html
                                              > [2] http://metalshop.homestead.com/hotwirefoamcutter.html
                                              > [3] http://www.youtube.com/watch?v=OLt5xUv7a8s
                                              > [4] http://metalshop.homestead.com
                                              > [5] http://OpenOSX.com
                                              >
                                            • Jeshua Lacock
                                              ... Yes - I know - I mentioned this earlier in the thread - that is essentially what the whole thread is about! ... In practice too. ... What exactly did you
                                              Message 22 of 26 , May 25, 2009
                                                On May 25, 2009, at 5:25 AM, postello@... wrote:

                                                > The Saturn engine
                                                > blocks have foam patterns that are invested in some sort of ceramic to
                                                > hold the shape, then packed in loose sand before pouring.

                                                Yes - I know - I mentioned this earlier in the thread - that is
                                                essentially what the whole thread is about!

                                                > That
                                                > technique gives more predictable dimensions, in theory.

                                                In practice too.

                                                > I just never
                                                > got it to work, personally.


                                                What exactly did you attempt? What was wrong? It works great!


                                                Best,

                                                Jeshua Lacock, Owner
                                                <http://OpenOSX.com>
                                                phone: 877.240.1364
                                              • Jeshua Lacock
                                                ... Read the thread! Best, Jeshua Lacock, Owner phone: 877.240.1364
                                                Message 23 of 26 , May 25, 2009
                                                  On May 25, 2009, at 6:12 AM, Ron Thompson wrote:

                                                  > There's your problem. Don't ram it, use loose sand. Put about 2 inches
                                                  > in the bottom of your flask/box/bucket and place your foam. Pour
                                                  > sand in
                                                  > around it, bumping the flask every now and then to settle the sand.
                                                  > When
                                                  > the sand is near the top of the sprue, you are ready to pour.


                                                  Read the thread!


                                                  Best,

                                                  Jeshua Lacock, Owner
                                                  <http://OpenOSX.com>
                                                  phone: 877.240.1364
                                                • Dave
                                                  in my photo album I have pictures of a lost foam part done using cnc. http://groups.yahoo.com/group/hobbicast/photos/album/1205431571/pic/list the finished
                                                  Message 24 of 26 , May 25, 2009
                                                    in my photo album I have pictures of a lost foam part done using cnc.
                                                    http://groups.yahoo.com/group/hobbicast/photos/album/1205431571/pic/list
                                                    the finished part was made using the pink foam and no surface coating.
                                                    the white foam machines better(more rigid)but needs a filler to get a good finish.

                                                    --- In hobbicast@yahoogroups.com, postello@... wrote:
                                                    >
                                                    > This works OK for simple shapes. It does not for the rings or pieces
                                                    > with undercuts.
                                                    >
                                                    > > There's your problem. Don't ram it, use loose sand. Put about 2
                                                    > inches
                                                    > > in the bottom of your flask/box/bucket and place your foam. Pour
                                                    > sand in
                                                    > > around it, bumping the flask every now and then to settle the sand.
                                                    > When
                                                    > > the sand is near the top of the sprue, you are ready to pour.
                                                    > > For the newbies reading this, keep your head away from the area
                                                    > over the
                                                    > > sprue. The smoke and fumes will flash into flame. Hold your breath
                                                    > as
                                                    > > you pour. Don't breath the fumes. Some people put a fan to their
                                                    > back,
                                                    > > blowing the fumes away from them.
                                                    > >
                                                    > > I use this method often to make ingots or to make stock for the
                                                    > milling
                                                    > > machine. I just use a scrap chunk of foam embedded in the sand to
                                                    > make
                                                    > > aluminum "planks."
                                                    > >
                                                    > > Jeshua Lacock wrote:
                                                    > >>
                                                    > >>
                                                    > >>
                                                    > >>
                                                    > >> On May 24, 2009, at 8:12 PM, Lyle wrote:
                                                    > >>
                                                    > >>   > So how'd you make the foam pattern?
                                                    > >>
                                                    > >> My friend's CNC machine. Working on one of my own too - another
                                                    > >> project requiring dimensional accurate castings.
                                                    > >>
                                                    > >> I found that ramming sand around foam can easy distort the pattern
                                                    > by
                                                    > >> 1/4" or more...
                                                    > >>
                                                    > >> Best,
                                                    > >>
                                                    > >> Jeshua Lacock, Owner
                                                    > >> <http://OpenOSX.com <http://OpenOSX.com>>
                                                    > >> phone: 877.240.1364
                                                    > >>
                                                    > >>
                                                    > >
                                                    > > --
                                                    > >
                                                    > >
                                                    > > Ron Thompson
                                                    > > Riding my '07 XL883C Sportster
                                                    > > On the Beautiful Florida Space Coast,
                                                    > > right beside the Kennedy Space Center,
                                                    > > USA
                                                    > >
                                                    > > http://www.plansandprojects.com
                                                    > > My hobby pages are here:
                                                    > > http://www.plansandprojects.com/My%20Machines/
                                                    > >
                                                    > > Visit the castinghobby FAQ:
                                                    > > http://castinghobbyfaq.bareboogerhost.com/
                                                    > >
                                                    > > Add yourself to the member map here:
                                                    > > http://www.frappr.com/castinghobby
                                                    > >
                                                    > > Want to have some fun? The next time you're at McDonald's, wait
                                                    > until
                                                    > > the kid has your change ready and then say "Wait, I've got the two
                                                    > cents."
                                                    > > -Ron Thompson
                                                    > >
                                                    >
                                                  • Lyle
                                                    Looks good Dave. Nice to see some real pictures.
                                                    Message 25 of 26 , May 25, 2009
                                                      Looks good Dave. Nice to see some real pictures.

                                                      --- In hobbicast@yahoogroups.com, "Dave" <odd_kins@...> wrote:
                                                      >
                                                      > in my photo album I have pictures of a lost foam part done using cnc.
                                                      > http://groups.yahoo.com/group/hobbicast/photos/album/1205431571/pic/list
                                                      > the finished part was made using the pink foam and no surface coating.
                                                      > the white foam machines better(more rigid)but needs a filler to get a good finish.
                                                      >
                                                      > --- In hobbicast@yahoogroups.com, postello@ wrote:
                                                      > >
                                                      > > This works OK for simple shapes. It does not for the rings or pieces
                                                      > > with undercuts.
                                                      > >
                                                      > > > There's your problem. Don't ram it, use loose sand. Put about 2
                                                      > > inches
                                                      > > > in the bottom of your flask/box/bucket and place your foam. Pour
                                                      > > sand in
                                                      > > > around it, bumping the flask every now and then to settle the sand.
                                                      > > When
                                                      > > > the sand is near the top of the sprue, you are ready to pour.
                                                      > > > For the newbies reading this, keep your head away from the area
                                                      > > over the
                                                      > > > sprue. The smoke and fumes will flash into flame. Hold your breath
                                                      > > as
                                                      > > > you pour. Don't breath the fumes. Some people put a fan to their
                                                      > > back,
                                                      > > > blowing the fumes away from them.
                                                      > > >
                                                      > > > I use this method often to make ingots or to make stock for the
                                                      > > milling
                                                      > > > machine. I just use a scrap chunk of foam embedded in the sand to
                                                      > > make
                                                      > > > aluminum "planks."
                                                      > > >
                                                      > > > Jeshua Lacock wrote:
                                                      > > >>
                                                      > > >>
                                                      > > >>
                                                      > > >>
                                                      > > >> On May 24, 2009, at 8:12 PM, Lyle wrote:
                                                      > > >>
                                                      > > >>   > So how'd you make the foam pattern?
                                                      > > >>
                                                      > > >> My friend's CNC machine. Working on one of my own too - another
                                                      > > >> project requiring dimensional accurate castings.
                                                      > > >>
                                                      > > >> I found that ramming sand around foam can easy distort the pattern
                                                      > > by
                                                      > > >> 1/4" or more...
                                                      > > >>
                                                      > > >> Best,
                                                      > > >>
                                                      > > >> Jeshua Lacock, Owner
                                                      > > >> <http://OpenOSX.com <http://OpenOSX.com>>
                                                      > > >> phone: 877.240.1364
                                                      > > >>
                                                      > > >>
                                                      > > >
                                                      > > > --
                                                      > > >
                                                      > > >
                                                      > > > Ron Thompson
                                                      > > > Riding my '07 XL883C Sportster
                                                      > > > On the Beautiful Florida Space Coast,
                                                      > > > right beside the Kennedy Space Center,
                                                      > > > USA
                                                      > > >
                                                      > > > http://www.plansandprojects.com
                                                      > > > My hobby pages are here:
                                                      > > > http://www.plansandprojects.com/My%20Machines/
                                                      > > >
                                                      > > > Visit the castinghobby FAQ:
                                                      > > > http://castinghobbyfaq.bareboogerhost.com/
                                                      > > >
                                                      > > > Add yourself to the member map here:
                                                      > > > http://www.frappr.com/castinghobby
                                                      > > >
                                                      > > > Want to have some fun? The next time you're at McDonald's, wait
                                                      > > until
                                                      > > > the kid has your change ready and then say "Wait, I've got the two
                                                      > > cents."
                                                      > > > -Ron Thompson
                                                      > > >
                                                      > >
                                                      >
                                                    • Lance
                                                      Group, Has anyone built or used a Babington ball burner to melt their metals? It s a waste oil burner with no nozzle to clog. If yes, what was/is your
                                                      Message 26 of 26 , May 25, 2009
                                                        Group,

                                                        Has anyone built or used a Babington ball burner to melt
                                                        their metals? It's a waste oil burner with no nozzle to clog.

                                                        If yes, what was/is your experience esp. vs propane?


                                                        ----------



                                                        lance
                                                        ++++

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