Seamus is showing you how he makes slip casts using a plaster mould he made last weekend
Some tips for slip casting below!:
1. Prepare the Mould: Make sure your plaster mould is clean and free from any debris or previous residue. Use a soft brush to clean out any dust or particles that may interfere with the casting process. Do so safely, don’t breath in any airborne plaster or clay particles, even if the moulds are really dusty use a respirator/mask.
2. Clay Slip Consistency: Ensure that your clay slip has the appropriate consistency for slip casting with a good mix. The slip should be smooth and creamy, similar to cream. It should flow easily but not be too thin or watery.
3. Pouring Technique: Slowly and steadily pour the clay slip into the mould. Pouring too quickly may cause air bubbles or uneven filling.
4. Drying: Once the excess slip has drained out, leave the mould undisturbed for a some amount of time to allow the cast to set. The time required for setting may vary depending on the thickness and moisture content of the slip, the temperature and humidity of the room and the efficiency of your plaster mould,
5. De-moulding: Carefully remove the cast from the mould once it has reached the desired dryness. Plaster moulds absorb moisture from the slip, aiding in the drying process. However, if the cast is removed too early, it may distort or collapse. Check the cast for firmness and handle it with care.
6. We don’t do any cleaning on the casting surface just clean any large pieces of excess clay that may be on the top or inside the plaster mould but if you are casting something intricate and detailed, then you would need to do more thorough cleaning.
Some Notes
We currently are pouring cups I have seen when pouring slip cast objects, pouring the clay in one spot can affect the glaze application later, so if you’re pouring an object of some kind, make sure you pour the slip evenly around the object and not in one area or spot, however because I am making cups I always pour the slip on the bottom of the cup which isn’t glazed and so does not affect the finished product.
Also when mixing the slip, I generally mix slowly, fast enough to mix thoroughly, but slow enough not to create a whirlpool to avoid any excess bubbles being created and then dragged into the slip.
That’s it for now. Enjoy your pottery making!
