Lost Wax, POP, and Sand

Discussion in 'Lost wax casting' started by Skratch, Nov 21, 2022.

  1. Skratch

    Skratch Silver

    I'm thinking of trying a lost wax pour using plaster of paris to encase the pattern then putting in
    rammed sand before melt out. Trying for a smoother finish.
    Does this sound feasible?

    Thanks for any input.
    Tops likes this.
  2. DJN Holistic

    DJN Holistic Silver

    I'd think that the plaster would shatter with the heat. Why not just do a shell cast with silica?
    Skratch likes this.
  3. Tops

    Tops Silver

    Can POP be mixed with anything common to make it more suitable as a low brow/low budget investment material?
    Asking for a friend who has a tub of POP sitting on the shelf ;)
    Skratch likes this.
  4. DJN Holistic

    DJN Holistic Silver

    I'm not sure. I'm on the look out for something suitable for act as core material for hollow casting. I've heard that mixing discarded shell material into PoP can work, but I've never tried it, have my doubts, and it wouldn't be suitable for what your looking to do anyway. I know that you can buy refractory plaster, so I guess it exists for a good reason.

    I'm not entirely sure what your trying to achieve. I'm guessing you're a sand caster primarily? But what your proposing sounds like a hybrid between sand, investment and shell casting. If you manage what you want from plaster layer, the sand aspect becomes redundant. At that point you're either shell or investment casting.
    Skratch and Tops like this.
  5. Al2O3

    Al2O3 Moderator Staff Member

    Opinions vary on this. Like about anything else, materials engineered and formulated for an intended purpose will likely perform better. There is an art caster "Rasper" here on the forum that has used a sand/plaster/ludo mix for statuary as have many art casters for years......with success. Ludo is just broken up investment from previous molds. I searched but I'll be darned if I can find his recipe in his posts. Perhaps he'll chime in.

    Tobho Mott also bought a lot of equipment from an retiring art caster that had his own formula. Perhaps he can point you toward that.

    Skratch and Tops like this.
  6. Mantrid

    Mantrid Silver

    ive used POP and sand mix for a core, it did the job very well. I dont think it would have the strength to resist outward forces from expanding wax as a relatively thin layer sourounded by sand. The sand would just be pushed out of the way. You could layer it on thick and reinforce with wire or enclose in a metal cylinder but if you do that you might as well just do investment casting.
    If you really want to get really basic then do it like they did in the bronze age and still do in poorer countries like india and africa, using clay and wires

    Tops and Skratch like this.
  7. Skratch

    Skratch Silver

    Thanks Mantrid, very interesting. I guess there is really nothing new under the sun.
    I'm amazed at the skill using primitive materials.
    I've tried several times to do lost wax, my results don't come close to the video but
    I learned something from it.
    Anyway I've abandoned this project, I had the pattern a few minutes from done and it
    broke. :mad: So just wood patterns for this child for a while. ;)
    Thanks to all for the input.

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