SPRESIN SRC Flex-It 90 Urethane Casting Resin — 946 ml Kit, Semi-Rigid & Abrasion-Resistant

SPRESIN SRC Flex-It 90 is a two-part semi-rigid urethane casting resin that cures into abrasion-resistant, tear-strong parts ideal for reusable moulds, gaskets, rollers and functional prototypes.

This 32 oz kit blends a reliable working time with a finished material that keeps shape under pressure while allowing thin sections to flex. Engineered for abrasion resistance, tear strength, and stable performance across thick and thin castings, Flex-It 90 bridges the gap between soft urethanes and fully rigid resins. It’s commonly chosen by prototypers, small-batch manufacturers, and advanced DIYers who need parts that withstand repeated motion, vibration, or exposure to oils and solvents.

How does Flex-It 90 perform when cast thick versus thin?

Flex-It 90 was designed to behave differently depending on cross-section. In mass or thick pours it cures to a semi-rigid state that resists deformation, while thin sections retain more flexibility to bend without cracking. This predictable differential makes one compound suitable for multi-feature parts.

• Rigid feel in thicker castings for structural stability.
• Flexible thin edges reduce stress concentrations and tearing.
• Consistent cure profile minimizes internal voids across thicknesses.

Is this resin durable enough for repeated demolding and abrasive use?

Yes — abrasion resistance and tear strength are key properties of Flex-It 90. It withstands repeated demolding cycles and contact with abrasive materials better than many soft urethanes, making it suitable for moulds and parts that see repeated service. Chemical resistance also helps when parts encounter oils or mild solvents.

• High tear resistance reduces edge failure during demolding.
• Abrasion-resistant surface extends part lifespan under friction.
• Good resistance to common oils and contaminants in workshop environments.

What kinds of projects is the 32 oz kit best suited for?

The 32 oz kit is ideal for testing, one-off prototypes, and small batch production where you need professional-grade results without large volume investment. It’s sized for trial runs, making moulds for repetitive casting, or producing functional parts like gaskets, rollers, and seals.

• Small-batch functional parts and prototype runs.
• Custom moulds for casting ceramics, resins, or soft materials.
• Replacement rollers, edge guards, or wear components for small machines.

How easy is it to mix and finish with typical workshop tools?

Flex-It 90 is a straightforward two-part system: measure, mix, and pour. It cures smoothly with minimal post-processing, and machines or trims cleanly once fully cured. Standard mixing cups, stir sticks, and release agents used for urethanes are compatible for most workflows.

• Simple two-part ratio and practical pot life for controlled pours.
• Sands, trims, and machines cleanly after full cure for finishing.
• Works well with common mould releases to prolong mould life.

Who is this for? SPRESIN SRC Flex-It 90 32 oz suits makers who need a mid-hardness urethane that balances strength and give. Choose it if you’re producing reusable moulds, mechanical seals, rollers, or prototype parts that face abrasion, repeated motion, or light chemical exposure. It’s an excellent step up from soft urethanes when you need improved structural integrity without losing thin-section flexibility, and the 32 oz kit is convenient for small professional runs, hobbyists testing a new design, or repair work where durable, semi-rigid parts are required.

Key features at a glance:

• Abrasion-resistant and tear-strong for high-use components.
• Semi-rigid behavior: rigid in mass, flexible in thin sections.
• Reliable two-part mixing system for consistent results.
• 32 oz size ideal for prototyping, testing, and small batches.