The Weakest Point
The rim (or lip) of your pot is the thinnest, most exposed part of the wall. As you pull, it gets worked more than any other section. Without attention, it becomes ragged, uneven, and dangerously weak.
What Happens to the Rim
With each pull, the rim gets squeezed, stretched, and lifted. By the time you have done three or four pulls, the top of the wall can be:
- Wavy: Thick and thin spots alternate around the rim.
- Split: A thin crack runs along the very top.
- Floppy: The rim can no longer support itself.
None of these problems are fatal: they are all fixable in the moment with compression.
Compressing the Lip
With the wheel at medium-low speed:
- Wet your fingers lightly.
- Pinch the rim gently between your thumb (outside) and index finger (inside), or use two fingers on either side.
- As the wheel rotates, move very slowly around the circumference, or stay still and let the wheel bring the rim to you.
- Apply light, even pressure. You are not squeezing hard, just smoothing and compressing.
The Result
A compressed rim feels smooth, looks even, and stands up straight. It will survive drying and handling without cracking.
When to Do It
Compress the rim after every pull, not just at the end. A rim that goes uncompressed for several pulls is much harder to rescue than one that is maintained throughout.
Rim Maintenance Routine
Use this loop while throwing:
- Pull wall
- Compress rim
- Re-wet lightly
- Recheck rim thickness
Frequent maintenance is easier than late repair.
Down the Rabbit Hole
Rim compression works because of compression at the particle level, where balanced inward forces realign and densify the clay body. Many potters use a small piece of chamois leather instead of bare fingers to smooth the rim, taking advantage of its soft, non-abrasive surface for a cleaner finish.
