PMC™-121 30/WET

Description

This urethane rubber is designed for mold-making and production casting. It features a 1:1 by volume mix ratio, simplifying measurement and preparation. The rubber cures to a Shore 30A hardness, providing flexibility and abrasion resistance, ideal for creating durable molds that capture fine details in sculptures, architectural elements, special effects, toys, and prototypes.

• Mix Ratio By Volume 1A:1B
• Mix Ratio By Weight 1A:1B
• Pot Life 30 minutes
• Cure Time 16 hours
• Shore Hardness 30 A
• Specific Gravity 1.04 g/cc
• Specific Volume 0.96 cm3/g
• Color Clear Amber
• Tensile Strength 27.58 bar
• Elongation @ Break 1,000 %
• 100% Modulus 565 kPa
• Die C Tear Strength 13.1 kN/m
• Shrinkage < .001 in. / in.
• Mixed Viscosity 1,800 cps

Instructions

Preparation

• Store and use materials at room temperature (23°C) with low humidity.
• Use products promptly due to limited shelf life.
• Wear safety glasses, long sleeves, and rubber gloves to minimize contamination risk.
• Ensure good ventilation in the workspace.

Sealing Porous Materials

• Seal models made of porous materials (e.g., gypsum, concrete, wood) before applying a release agent.
• Use fast-drying sealers like SuperSeal™ or One Step™ without affecting surface detail.
• Shellac is suitable for rough contours and sealing sulfur or moisture-containing clays.
• Thermoplastics require sealing with shellac or PVA.

Non-Porous Surfaces

• Only a release agent is needed for metal, glass, hard plastics, and sulfur-free clays.

Applying a Release Agent

• Use a mold-making specific release agent (e.g., Universal™ Mold Release).
• Apply liberally and brush lightly with a soft brush for thorough coverage.
• Follow with a light mist coating and let dry for 30 minutes.

Measuring & Mixing

• Store and use materials in a warm environment (23°C).
• Pre-mix Part B before use. Mix equal amounts of Parts A and B for at least 3 minutes, scraping sides and bottom.
• For large quantities (7 kg or more), use a mechanical mixer followed by hand mixing.
• Vacuum degassing can further reduce air bubbles.

Pouring

• Pour mixture at the lowest point of the containment field to minimize air entrapment.
• Ensure the liquid rubber levels off at least 1.3 cm above the highest model point.

Curing

• Allow curing for at least 16 hours at room temperature (23°C) before demolding.
• Cure time can be reduced with mild heat or a cure accelerator.

Post Curing

• Heat cured rubber to 65°C for 4 to 8 hours to enhance properties.

Using the Mold

• Apply a release agent before each casting.
• Use appropriate release agents for different materials (e.g., wax, liquid rubber).
• Sponge mold with soap solution before casting gypsum plaster for better flow and release.

Performance & Storage

• Fully cured rubber is durable if properly used and stored.

Specifications