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Making Moulding Sand

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  • Making Moulding Sand

    Looking for some suggestions on making molding sand for aluminum. I sifted some silica sand from Home Depot and mixed dry with 10 to 15 % Ball Clay I had leftover from the kiln but does not seems to have enough bonding.
    Any one that have had a simple as possible mix and ratios.
    Any suggestions?
    Thanks

  • #2
    I made some last year in about the same ratio, only I used ground kitty litter (bentonite). I found it tough to bond without adding too much water. The more I "worked" it the better it got though, and it would probably really benefit from a muller. It's certainly usable, but not the greatest. When the weather warms up a bit and I get back into casting I'm just going to go the commercial petrobond route this time as I just want to cast stuff, and not make stuff, to make stuff, to make stuff anymore.

    I do plan to build a muller eventually as well.

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    • #3
      can't remember offhand, but I did ask a foundry customer his suggestions and noted them here - I think it was in a thread Dan had going on the same topic. Should come up in a search
      in Toronto Ontario - where are you?

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      • #4
        Would this help?: https://www.reliance-foundry.com/blog/foundry-sand

        Ian
        All of the gear, no idea...

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        • #5
          Bentonite clay can be gotten from farm supply places. I got some from a local farmers' Coop store, where it's sold for lining farm ponds. Mine was free, since they were happy to let me haul away a couple of burst, leaking bags of it.

          As for the petrobond, I've never tried it, but have wondered how it would work to mix in a little motor oil. I've never handled any petrobond, but I assume it has some type of oil mixed in.
          Lynn (Huntsville, AL)

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          • #6
            Originally posted by lynnl View Post
            Bentonite clay can be gotten from farm supply places. I got some from a local farmers' Coop store, where it's sold for lining farm ponds. Mine was free, since they were happy to let me haul away a couple of burst, leaking bags of it.

            As for the petrobond, I've never tried it, but have wondered how it would work to mix in a little motor oil. I've never handled any petrobond, but I assume it has some type of oil mixed in.
            I'm on the fence between green sand and petrobond, but I do want to go with a commercial product moving forward. Too many variables when I DIY everything from the start, and I'd rather focus on making good castings instead. There's one guy on you tube who's name escapes me atm who adds a tablespoon of non detergent motor oil every time he mulls a batch of petrobond. I can't comment on whether that's standard practice or advisable or not, Just stating I've seen it done.

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            • #7
              When I was a kid my father and another guy shared a shop. My father did the machining and the other guy ran a small foundry. I do recall that the casting sand was MUCH finer than anything found at a masonry supply place.

              They only did aluminium castings. And I certainly never saw him oiling the sand. But he did occasionally fortify the pile of sand with a bag of some powder or other. And a bit of water of course to keep it the proper stickiness.

              The casting sand also has a very dark brown look to it. So I'm pretty sure it's far from being regular silica sand.

              All in all I think I'd go talk with a local aluminium foundry and see if they will sell you a pail of it for a donation to the coffee fund or in exchange for a couple dozen beer. They probably sweep up and throw away more in a month of floor cleaning then you'd use in your lifetime.
              Chilliwack BC, Canada

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              • #8
                I don't believe sand with a lot of silica dust is involved or every molder would have Silicosis.
                Last edited by reggie_obe; 03-17-2021, 07:10 PM.

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                • #9
                  Originally posted by BCRider View Post
                  When I was a kid my father and another guy shared a shop. My father did the machining and the other guy ran a small foundry. I do recall that the casting sand was MUCH finer than anything found at a masonry supply place.
                  +1 on the observation of how fine the sand is. A close friend of mine worked at a small aluminum foundry not far from here. I was having a few things cast for a company I worked for, I had made the patterns (very simple ones!) and when I dropped them off I got a tour. I noted the same thing about the sand, it was extremely fine. Finer than typical beach sand or as BCR said, than anything I've ever seen used for typical masonry work. That jumped out at me as well. It was all green sand, no petrobond, if I recall correctly.

                  No idea if the place is still in business. It was a small family run place, pretty much all manual operation with just two small gas fired melting furnaces.

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                  • #10
                    Originally posted by Ian B View Post
                    Certainly it did. Thank you very much. Very Good explanations. Copied and pasted on my WinWord to rear and reread

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                    • #11
                      This guy uses grout mix and motor oil. Looks interesting, although I haven't tried it.

                      https://youtu.be/ogN69cQ-r1w

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                      • #12
                        Originally posted by kev74 View Post
                        This guy uses grout mix and motor oil. Looks interesting, although I haven't tried it.

                        https://youtu.be/ogN69cQ-r1w
                        Motor oil?? I would think that would create an awful lot of smoke.

                        I remember in our high school shop they had some casting clay that was deep red in color. It was very fine and had a sticky consistency like clay.

                        JL....

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                        • #13
                          I watched a youtube video of a guy using molasses and sand. He has some videos making some really nice looking castings.
                          Have never tried it but looks interesting.

                          https://www.youtube.com/watch?v=ToWAUA5CRs8

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                          • #14
                            consider water glas. you can harden it with co2 if in a hurry.

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                            • #15
                              Not a lot of help, but when I was casting I went and dug up some sand from the local sandy place
                              Fortunate to live where the Mansfield Red moulding sand vein runs...

                              Dave
                              Just south of Sudspumpwater UK

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