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Smooth-Cast™ 300

Smooth-Cast™ 300 vs. Smooth-Cast™ 325

Bright White Liquid Plastic

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Smooth-Cast™ 325

Smooth-Cast™ 300 vs. Smooth-Cast™ 325Smooth-Cast™ 300

Ultra Low Viscosity Liquid Plastics

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Key Differences

ColorWhiteClear Amber
Elongation @ Break5 %10 %
Compressive Modulus45,800 psi36,500 psi
Flexural Modulus128,000 psi101,000 psi
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All Technical Data

Smooth-Cast™ 300Smooth-Cast™ 325
Product Type
  • Urethane Resins
  • Urethane Resins
Mixed Viscosity80 cps100 cps
Mix Ratio By Volume1A:1B1A:1B
Mix Ratio By Weight100A:90B115A:100B
Pot Life3 minutes2.5 minutes
Cure Time10 minutes10 minutes
Shore D Hardness7072
Specific Gravity1.05 g/cc1.07 g/cc
Specific Volume26.4 cu. in./lb.25.9 cu. in./lb.
ColorWhiteClear Amber
Tensile Strength3,000 psi3,170 psi
Tensile Modulus139,500 psi140,000 psi
Elongation @ Break5 %10 %
Compressive Strength4,000 psi3,500 psi
Compressive Modulus45,800 psi36,500 psi
Flexural Strength4,510 psi3,690 psi
Flexural Modulus128,000 psi101,000 psi
Shrinkage0.01 in. / in.0.01 in. / in.
Heat Deflection Temp120 °F120 °F

Product Description

Smooth-Cast™ 300

The Smooth-Cast™ 300 Series of liquid plastics are ultra-low viscosity casting resins that yield castings that are bright white and virtually bubble free. Vacuum degassing is not necessary. They offer the convenience of a 1A:1B by volume or 100A:90B by weight mix ratio. The differences between them are pot life and demold time.

These resins readily accept fillers (such as URE-FIL™ 3 ) and can be colored with SO-Strong™ or Ignite™ color tints (Smooth-Cast™ 325 series accepts pigments better than the Smooth Cast™ 300 series). Fully cured castings are tough, durable, machinable and paintable. They resist moisture and mild solvents. Applications for Smooth-Cast™ 300 Series Liquid Plastics include reproducing small to medium size sculptures, making prototype models, special effect props and decorative jewelry.

Those interested in making roto cast pieces should refer to the Smooth-Cast™ 65D technical bulletin.

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Smooth-Cast™ 325

The Smooth-Cast™ 325, 326 & 327 ColorMatch™ Series plastics are urethane resins that were developed specifically for adding color pigments and fillers to achieve true color representation or filler effect. The ColorMatch™ Series is formulated “color neutral”. Small amounts of pigment will yield accurate, vivid colors from cured castings using So-Strong™ tints, UVO™ pigments or Ignite™ color pigments. The ColorMatch™ Series offers the convenience of a 1A: 1B mix ratio by volume and has a very low viscosity. Demold times range from about 10 minutes to 2-4 hours (depending on product, mass and mold configuration). Note: Large mass castings will get very hot and shrink more, depending on mold configuration.

The ColorMatch™ Series also readily accept fillers (such as URE-FIL™ 3 from Smooth-On). Because of its neutral color, Smooth-Cast™ 325 is ideal for creating marble and wood grain casting effects, or duplicating the look of real metal by adding bronze, brass or other metal powder. Applications for the ColorMatch™ Series plastics include making pigmented prototype models or figures, special effect props, reproducing small to medium size sculptures, decorative jewelry, etc.

Click here for more Smooth-Cast™ resin products.

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