5 Ways You Can Help Stop Your Pottery Cracking

1.

Make sure when you start that the clay you use is the same degree of wetness. One of the major causes of cracks is different degrees of wetness when constructing the piece. If you are making a large piece, try wrapping your clay and even your piece, in a moist towel or plastic so that it doesn’t dry out while you work.

2.

Joins in the clay are the main location for cracks. To avoid them, make sure you use a slurry (a mixture made from the clay you are using and water or vinegar – mixed to a toothpaste consistency), roughly score your two edges and apply the slurry to both edges of your join. Give the join a good wiggle using a little pressure to help fuse the two pieces, until it doesn’t wiggle anymore and then smooth or finish the edge in your preferred style.

3.

Try to avoid too much contrast in the thickness of your piece. This can be difficult, so wrap your piece well with plastic to allow for even drying to occur. Pay particular attention to the thinner elements of your piece.

4.

Support your piece with sponges, moist towels or newspaper as you create, so that there is no excessive weight during the construction – which can put undue pressure on the drying clay.

5.

Make sure to wrap your finished piece in plastic so that it dries slowly. This will help in reducing any cracks that may appear if the piece dries too quickly. The speed of drying is one of the most common causes for pieces cracking.

Oh No, I’ve Got a CRACK!

If you do get a minor crack in your leather hard piece, clean out the crack with a tool like the one shown below, so that there are no shards or burrs remaining in the crack. Then make up a slurry of white vinegar and clay (the same clay as you used in your construction), and push it into the crack. Use the tool to help get it right into the crack so that there are no cavities left that can trap air. Then use a brush with vinegar or water to smooth out the repair excess. Wrap your piece well so that it dries slowly and evenly.