Jesmonite & Plaster Mix Split Calculator
Obtain the exact grams of Jesmonite AC100 base powder and liquid acrylic resin needed for casting trays, planters, and plates. Includes custom waste sliders.
Jesmonite & Plaster Calculator
Measurement Outputs
Contextual Shopping Kit
Composite casting material kit containing liquid resin and mineral base powder.
View on AmazonEnsure perfectly flat coasters and trays with an adjustable leveling table.
View on AmazonCalculating Jesmonite AC100 Mix Ratios by Weight
Jesmonite AC100 is an eco-friendly water-based composite material containing a reactive mineral base (powder) and a water-based acrylic resin (liquid). Unlike traditional plaster of Paris or concrete, Jesmonite requires a strict weight proportion of **2.5 parts base powder to 1 part liquid resin** (2.5:1 ratio).
Because Jesmonite is dense (average dry density is 1.75 to 1.80 grams per milliliter), you need significantly more weight of material compared to the volume of your mold. For a 100 ml mold cavity, you must prepare approximately 175 to 180 grams of mixed material.
Total Mixed Weight = Volume (ml) × 1.75 × (1 + Waste Factor / 100)
Liquid Weight = Total Mixed Weight / 3.5
Powder Weight = Liquid Weight × 2.5
Mixing and Curing Best Practices
When working with acrylic composites, follow this sequence to avoid dry lumps or flash-curing:
- Liquid First: Always weigh the liquid component and pour it into your mixing bucket first. Do not add water.
- Sift the Powder: Slowly add the powder to the liquid while mixing continuously with a high-shear blade or paint mixer.
- Pop Air Bubbles: Tap the sides of the mixing container and vibrate the mold immediately after pouring to release trapped air.
- Curing: Jesmonite releases heat (exothermic reaction) and cures rapidly inside the mold (usually demoldable in 30-40 minutes). Let it fully cure in a dry room for 24 hours to achieve maximum compressive strength.