This simple tool helps you get wobbly rims on wet or leather soft pots back to being circular/round.

If you’ve spent any time at all throwing pots on the wheel you’ve found yourself with a wobbly rim. Maybe it got bumped accidentally, tugged by plastic covering, was thrown a bit off center, or even just dried unevenly leading to more of an oval-shaped rim than a circle-shaped one. There aren't many techniques for fixing this once a pot is off the wheel, and I'm sufficiently clumsy (thanks ADHD!) that I started testing out my own approaches. I landed on this cone shape after seeing some other potters use terra cotta pots for this. This plastic cone is easier to handle and wash, and it works with a wider range of pot sizes so you don't have to keep a fleet of terra cotta pots around.

By inserting it into your still-malleable pot and applying a little pressure you can gradually coerce the rim of the pot back into a round shape, removing wobbles and ovular shapes before trimming and bisque firing. For small pots it's often easier to do this the other way around—place the cone on a surface with the pointy end up and gently press the pot down over it.

I also make a version of this that makes a more triangular shaped rim if that sounds interesting: https://etsy.me/3HAY509

The wide end of the cone is 145mm in diameter (a bit over 5 ⅝ inches) and the narrow end of the cone is 40mm (a bit over 1 ½ inches). Works best for pots with an inner-diameter between 50-140mm (roughly 2" to 5 ½"). Need a different size? Let me know!

Note: The legacy version is only 120mm at the top and is taller, which means it does worse for short vessels like bowls.

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Products are made with a renewable bioplastic called PLA. It's made from starches instead of fossil fuels, making it more ecologically considerate, but it doesn't tolerate high temperatures or exposure to UV well. To ensure your tools last for a long time, avoid leaving them in a hot car or out in the sun.