Measuring pot bottoms

[JohnnyK 140]

I have read in the forums and watched on YouTube various ways of determining the thickness of the bottoms of pots prior to trimming but have yet to see a simple method that I learned in my first pottery class about 10 years ago. It incorporates the use of 2 straight edges and can be used on pots of any size or shape. In the attached pix you can see how to use a straight edge and a ruler which will tell you in inches (or millimeters) the exact thickness, or you can use a couple of skewers and a marker to give you a visual representation. This way you don't have to tap the bottom while you are trimming to decide if it sounds about right or try to use your fingers to estimate the thickness. It's a real pain for beginners to use these methods and find that they were off just a little as they punched through the bottom of their pot.

Using this method, you take a measurement from the inside of the pot. Then you take a measurement from the outside and subtract the two and you will know exactly how thick the pot bottom is. Give it a try the next time you trim your pots!

[clay lover 152]

I do this , using 2 hair pins that will stay in place on the chopstick, but can be adjusted for each pots, rather than making marks.  Remember to set the pins at the bottom of the chopstick for accuracy.  Then I trim out the very center at the desired depth, knowing I can go deeper as the bottom curves up out to the foot ring.

 

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Edited Wednesday at 04:16 PM by clay lover

[graybeard 19]

Im confused. Why not just use a needle tool?

What am I missing?

[Dick White 193]

I think the challenge in the question is how to determine the thickness of the leatherhard base before trimming without leaving a destructive hole through the bottom of the vessel (that will later leak, or at a minimum, require effort to repair).

[clay lover 152]

Needle tool holes,have,a,way of reappearing after glaze firing.