Flex 20 Flexible Urethane Rubber
Flex 20 is a soft yet tough urethane rubber designed for high-detail casting, prototyping, and mold-making. With a shore hardness of 20A, it offers maximum flexibility while maintaining excellent tear strength and durability. This makes it perfect for automotive, medical, and gasket applications, as well as custom molds and soft rubber parts. Its low viscosity ensures incredible detail reproduction, and vacuum or pressure casting is recommended for bubble-free results.
Whether you need a highly flexible rubber for gaskets, medical parts, or intricate molds, Flex 20 delivers precision, durability, and ease of use!
Features
✅ Smooth, Detailed Castings:
Low viscosity allows for excellent detail reproduction
✅ Bubble-Free Results:
Vacuum or pressure casting recommended for best quality
✅ Customizable Colors:
Mix with Alumilite translucent dyes, and add white dye for opaque colors
✅ Fast Demold Time:
Ready to demold in 2 hours, full cure in 72 hours
✅ Versatile & Flexible:
Ideal for automotive parts, soft molds, gaskets, and prototypes
✅ Minimal Shrinkage:
Ensures high accuracy and precise castings
🚫 Not as rigid as higher shore rubbers like Flex 50, 70, or 80
FAQ
What makes Flex 20 different from other urethane rubbers?
✅ Flex 20 is the softest and most flexible in the Flex Series, with a 20A shore hardness, making it perfect for gaskets, prosthetics, and ultra-flexible molds. It provides maximum stretch and detail without tearing.
Can Flex 20 be used for wearable applications?
🚫 No, Flex 20 is not certified for skin or body contact and should not be used for wearable items like prosthetics or masks.
Does Flex 20 work well for impact-absorbing parts?
🔨Yes! Its soft, rubber-like texture helps absorb impact, making it useful for shock-absorbing components, protective pads, and cushioning applications.
Can I use Flex 20 for high-stress parts?
⚠️ While it is durable, Flex 20 is not designed for load-bearing or high-tension applications. If you need more strength, consider Flex 50 or higher shore rubbers.
How does Flex 20 handle repeated bending and stretching?
🔄 Flex 20 can withstand repeated flexing without cracking or breaking, making it ideal for applications requiring frequent movement.
What’s the best way to mix and pour Flex 20?
🎨 Mix at a 1:1 ratio by weight or volume, stir thoroughly, and pour slowly to reduce air bubbles. If possible, use a vacuum chamber for best results.
Can I use Flex 20 to cast clear parts?
🚫 No, Flex 20 is naturally ivory-colored and cannot be made fully transparent. However, it accepts dyes well for custom colors.
How should I store my urethanes to keep them in the best condition?
❄️ Store your urethanes in a cool, dark place away from direct sunlight and high temperatures, ideally between 60°F and 75°F (15°C to 24°C). Keep the container tightly sealed to prevent moisture and air from affecting the formula. Wiping the container tops before sealing can help prevent stuck caps.
What are the best conditions for pouring and displaying urethane projects?
☀️ For the best results, pour urethanes in a well-ventilated, temperature-controlled environment with humidity below 60% to prevent defects and bubbles. Once cured, keep finished projects out of direct sunlight to prevent discoloration or degradation.
Downloadable Resources
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