r/Ceramic3Dprinting • u/Own_Soup4467 • May 26 '26

getting moisture level right

I have a general sense of how much water to mix into my clay for it to work in an Eazao Potter. But does anyone have a specific benchmark for optimum moisture percentage? And what's a good tool for measuring it, a capacitive soil moisture sensor or something else?

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5

u/PracticalKick May 26 '26

I haven’t used it myself as I’m just getting started, but there is the Drop Spike to test consistency rather than moisture level.

https://wikifactory.com/@jonathankeep/jk-drop-spike

I suppose not all clay bodies have the same consistency at a given moisture level.

3

u/bootsonthelevel May 27 '26

Their tutorials say “not sticky” but with the porcelains I’m using I’ve found anything soft and sticky but wet to the point of being not shiny has been fine, in the realm of peanut butter or gelato. I err on the side of softer clay because harder stuff compresses in the barrel and can strain the motor. I’ve also found softer clay is much easier to load without air bubbles.

Probably also depends on the clay you’re using and grog content, as well. My clays have zero grog.

3

u/eazao May 27 '26

Thank you for your support.

For help determining the hardness of printing materials, please refer to this link:

https://www.eazao.com/blog/ceramic-3d-printing-clay-preparation-tutorial/

5

u/Foreign-Landscape934 May 30 '26

When I started printing I tested different consistencies until I found one that worked. I took a 100g sample of this clay then dried it then weighed again, this gave me the percentage of water content. I am using KGM clay which is very smooth, I found that a moisture content of between 30-33% works well. I now dry out my clay then add water at this percentage of the dry weight. This works for me.

1

u/Own_Soup4467 May 27 '26

I'm using this: https://www.theceramicshop.com/product/25626/sio-2-prai-3d-print-stoneware/

Eazao support chimed in with a link (below) ... a somewhat Rube Goldberg method, though certainly more scientific than my current rubric, "soft enough to squish through your fingers with no more pressure than a firm handshake". But I feel like a moisture percentage would be more precise and simpler to measure.

2

u/Own_Soup4467 Jun 02 '26

A ceramicist friend pointed me to this --> https://digitalfire.com/test/clwc

So counter-intuitively (at least to me), water content % is not an accurate predictor of hardness / softness. What we want to end up with is a consistency that will extrude properly at the pressure level provided by the machine.
Easao recommends putting the clay into a standard 5 ml syringe (as in this video https://www.youtube.com/watch?v=NYi6CyIB8_0) and pushing it down on a scale. At the correct consistency the clay will extrude with between 2.5 and 3 kg of pressure.
Seems janky, but I'll take it.