The primary method for attaching clay to clay is called "score and slip," ensuring a strong and lasting bond.
Here's a breakdown of the process:
Score the Clay Surfaces
- Use a sharp tool, such as a needle tool, fork, or scoring tool, to create a textured surface on both pieces of clay you want to join. This involves making cross-hatch marks. Think of it like roughening the surface of wood before gluing.
- The scoring should be deep enough to create grooves but not so deep that you compromise the structural integrity of the clay.
Apply Slip
- Slip is essentially clay in liquid form. It acts as a glue between the scored surfaces. You can make slip by mixing clay scraps with water until you achieve a creamy consistency.
- Apply a generous amount of slip to both scored surfaces. Make sure to get it into all the grooves you created during scoring. If you don't have slip, water can sometimes work in a pinch, but slip provides a much stronger bond.
Join and Blend
- Press the two scored and slipped surfaces firmly together. Wiggle them slightly to ensure good contact and interlock the clay.
- Once joined, use a tool (like a wooden rib or your fingers) to blend the seam where the two pieces meet. Smooth the clay and remove any excess slip that squeezes out. This blending strengthens the join and creates a seamless appearance.
Important Considerations:
- Clay Consistency: The best results are achieved when joining clay pieces of similar moisture content. If one piece is significantly drier than the other, the join is more likely to crack during drying and firing.
- Pressure: Apply adequate pressure when joining the pieces, but avoid distorting the shape of the clay.
- Thoroughness: Make sure the scoring and slipping are thorough. Don't skip any areas of the joining surfaces.
- Drying: Dry the joined piece slowly and evenly to minimize stress and prevent cracking. Covering the piece with plastic loosely can help.
- Air Pockets: Avoid trapping air pockets in the join, as these can cause explosions during firing.
