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Lost styrofoam casting!

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  • Lost styrofoam casting!

    I would like to try some lost styrofoam casting and am wondering if any has any advice. What tyrofoam to use, glue needed, etc.
    mark costello-Low speed steel

  • #2
    Seeing as how you have to build the mlod for the foam casting to start with I can't see this as a really practical approach for the HSM uless you are going to carve the master out of foam to start with JMO
    Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.


    • #3
      When doing foam casting there are two main types of foams - the polystryrene that we see in packaging which has bubles in it and there is another type available from plastic/foam suppliers which has very fine bubbles. The latter will give you a better finish.

      what are the steps in foam casting

      1. carve the object out of foam

      2. attach a sprue

      3. coat with a wallboard ceramic coating to improve surface finish and allow to dry (this step is optional)

      4.put the pattern in a bucket of fine, clean dry sand with the sprue sticking out of the top

      5. Pour metal in as quick as you can!

      best of luck with it

      The tinkerer


      • #4
        Step 6 above should be: make sure you dont breath the fumes coming from the burning styrofoam.

        [This message has been edited by Carl (edited 06-12-2005).]


        • #5

          Lost foam casting seems to be a quick and effective way to make mlods.

          Search hot wire foam cutter and you will find much info on making a cutter for your foam as well as casting techniques.

          Here is a pic of my hot wire cutter as well as a metal template and a couple of castings for trial.

          I have gotten to the point of making sheet metal cutting templates bent to cut two sides of a part in the wire cutter in one setup.

          Use your imagination and don't feel as negative as spindoctor in your thoughts.

          My hot wire rig consists of 4' of nicrome wire (.024"), a battery charger, and a harbor freight router controller.

          lots of luck



          • #6
            Just a note for the safety concious.

            The gas- or when I wanted to do it- was phosgene.

            Lest we forget, there are a lot of tidy white graves from many nations in France as a result.



            • #7
              For a hot wire cutter, I just grabbed a piece of stainless tie wire that I had on hand. Worked good. Fed a 6A battery charger with a variable transformer set at about 40%.

              If you are not on top of metalurgy, just use broken up castings for your melt. Heavy pieces can be "roasted" over your fire until they get crumbly and broken up to fit your pot.

              Wait 'til your melt is a little pink before you pour.

              It takes a hot fire and a L-0-0-0-NG time to melt. I finally made an melt oven out of Kaowool (from McMaster Carr) to stop loosing heat and speed things up. Just a round wire mesh cage with 2" Kaowool wire-tied to the inside. Fired with propane.

              One time I forgot to watch it, the aluminum appeared to be on fire then the 1/4" steel pipe pot burned through. Luck I still have feet. Plan on anything going wrong.


              • #8
                some good info here

                Rgds, Lin


                • #9
                  An excellent reference web site on this process:
                  Richard Montgomery
                  Robert, LA


                  • #10
                    Another one:
                    Richard Montgomery
                    Robert, LA


                    • #11
                      Kap, those castings for an oddball 0-4-0 frame? As for the hotwire, stainless steel fishing leader works very well too and ofcourse, is easy to find.

                      [This message has been edited by BillH (edited 06-13-2005).]


                      • #12
                        Look like truck frame castings to me....

                        Andy Pullen
                        Clausing 10x24, Sheldon 12" shaper, Clausing 8520 mill, Diacro 24" shear, Reed Prentice 14" x 34"


                        • #13
                          <font face="Verdana, Arial" size="2"> stainless steel fishing leader works very well too and ofcourse, is easy to find.
                          so to for a guitar string, high e - also has lots of nickel in it.
                          in Toronto Ontario - where are you?


                          • #14
                            Ford (and probably a bunch others by now) uses lost foam casting for engines.

                            They are able to get 3 whiskers from net shape and extremely complicated designs.

                            I interviewed one of their engineers some years ago..."P.Poor Memory says the plant was in NY state?


                            • #15
                              Thanks all, now to get busy and cut some foam!
                              mark costello-Low speed steel