Universal Quoting Formula: Total Job Price = (Raw Material COGS + Machine Depreciation & Energy + Finishing Labor) / (1 - Target Margin %).
All variables calculate locally in real time. Standard commercial margins are 50%–65% for B2B contracts and 65%–80% for custom retail orders.
How to Accurately Calculate Silicone & Resin Quantities
Mixing liquid synthetic polymers (platinum addition silicones, tin polycondensation rubbers, and bisphenol epoxy resins) without precise volumetric and stoichiometric calculations leads to sticky uncured zones, air entrapment, and costly material waste.
1. Specific Gravity and Densities of Common Casting Materials
| Polymer Chemistry | Specific Gravity (g/cm³) | Mix Ratio by Volume | Mix Ratio by Weight | Linear Shrinkage |
|---|---|---|---|---|
| Platinum Silicone (Shore 30A) | 1.08 g/cm³ | 1A : 1B | 100A : 100B | < 0.1% |
| Tin Condensation Silicone | 1.15 g/cm³ | 10A : 1B | 100A : 10B | 0.2% – 0.4% |
| Deep Pour Epoxy (River Tables) | 1.10 g/cm³ | 2A : 1B | 100A : 43B | 1.5% – 2.5% |
| Rigid Polyurethane Resin | 1.05 g/cm³ | 1A : 1B | 100A : 90B | 0.5% – 0.8% |
2. Why Mixing by Weight on a Digital Gram Scale is Mandatory
Measuring cylinders and mixing cups are prone to meniscus reading errors and wall retention. Always use a calibrated digital scale accurate to 0.1 grams. Pour Part A first into a clean polypropylene mixing container, tare the balance to zero, and dispense Part B to the exact calculated target weight.