I am doing some plastering work in my house, and I am finding it difficult to find powdered plaster in Bunnings suitable for the work. There is plenty of premixed plaster, and lots of powdered plaster that is fast setting, but i just want plain old powdered plaster that is not fast setting (so is easily sandable), that i can easily mix to different consistencies depending on what i want to use it for. Does Bunnings sell it, and if so - what is is called?