Reclaim yield is a dry-solids question
A bucket containing 10 kg of wet trimmings does not contain 10 kg of clay solids. Part of that scale reading is water. Combining bone-dry and plastic scrap therefore starts by converting both streams to dry-clay equivalent. This tool uses moisture on a wet basis:
Bone-dry scrap is treated as dry solids. The two amounts are added, then the entered process-loss percentage is applied. Process loss can represent clay left in buckets, settled material discarded with water, screen residue and handling losses. Measure it over several batches if the number will be used for purchasing or production planning.
How to measure wet-scrap moisture
Take a representative sample, weigh it in a labelled heat-safe container, dry it fully using a suitable studio procedure, cool it away from ambient moisture and weigh it again. Subtract the empty container in both readings. On the wet-basis convention used here:
A 100 g sample that finishes at 78 g contains 22 g water and is 22% moisture on a wet basis. Some ceramic records express water relative to dry solids instead. Those conventions produce different percentages, so write the basis next to every moisture value.
Target working mass and water adjustment
After estimated solids recovery, the calculator rebuilds the mass needed at the target moisture:
The water already present in wet scrap is reduced by the same process-loss assumption, then compared with the water required at the target. A positive adjustment means add water; a negative value means water must be removed through settling, filter pressing, plaster drying or another controlled dewatering step.
This is mass balance, not a recipe for dumping the full adjustment into a mixer at once. Moisture distribution, particle wetting and ageing affect working feel. Approach the result in stages, mix thoroughly, rest the body and check a weighed sample before final wedging.
What the model assumes
- The “dry” stream is actually bone dry; damp greenware belongs in the wet stream.
- Loss removes material in the same overall water/solids proportion. If only coarse dry screen residue is discarded, measure streams separately for better accuracy.
- No soluble-material or deflocculant adjustment is modelled.
- The equivalent bag count uses 12.5 kg only as a planning reference, not a universal commercial package size.
Close the loop with one real batch
Weigh the incoming scrap, recovered clay and discarded residue. Measure final moisture and compare the actual working-clay mass with the prediction. That gives a studio-specific loss rate for the next batch. Keep different clay bodies, firing ranges and contaminated floor sweepings separate. Before reclaim enters important work, compare its plasticity, drying response, shrinkage and fired absorption with the fresh body.