There are two popular testing methods in the laboratory that can be related to this characteristic the AFS 25 micron clay wash and a screen analysis of the molding sand.
Another rule of thumb is that the total quantity determined in the AFS 25 micron clay wash should be 1.
The core bar rotates horizontally as layers of rope, loam molding material and clay wash
(to keep each mold layer from adhering to each other) are applied.
After completing the dry sand sieve analysis, conduct the AFS clay wash
and sieve analyses on the same sand sample.
The sand is then pretreated for five minutes with water and a dispersing agent in a high-speed mechanical stirrer to loosen the clay before performing the clay wash.
The AFS Clay wash can take several hours with high clay molding sands, but the washing device performs the cycle unattended.
The 25 Micron Clay Test provides an alternative to the autoclay method of performing a clay wash.