Oct 22, 2026: We are working on protecting our servers against the PHP2Shell vulnerability recently discovered. Servers were upgraded ahead of schedule on Oct 21. This could cause some issues. Please contact us if you encounter any.
These lumps do not break down easily in a dry mixer, even when with other materials (like silica and feldspar). And they just bounce around on a vibrating screen. That means that without some sort of finishing device in the dry material feed stream is needed to break down these lumps before the pugmill.

This picture has its own page with more detail, click here to see it.
This brushing engobe has already passed my EBCT test for use on the intended body. It is thick and gooey (because it contains CMC gum), so it is practically impossible to sieve. My regular propeller mixer is not able to break up the tiny agglomerates of New Zealand kaolin. But 30 seconds of blender mixing makes it as smooth as silk. To make this liter of brushing engobe, I use 800g of powder and 10g of CMC gum in 800g of water. Because of the very high clay content, this does not require Veegum to gel it. The CMC gum greatly improves the brushing properties. It also thins the slurry enough to enable its lower-than-normal water content, making it more suitable for painting onto leather-hard ware, often in as little as one coat.
| Materials |
New Zealand Halloysite
The whitest burning kaolin available to potters. Low plasticity. Very sticky when wet, suspends glazes well. |
| Glossary |
Agglomeration
The fine mineral, oxide and clay particles used in ceramics often aglommerate during storage or even in the latter stages of production. These must be broken down later. |
![]() PayPal | No tracking, No ads, No paywall, No transient content! Just organized, concise information constantly updated and improved. Was this helpful? Consider supporting me. |
Buy me a coffee and we can talk