VFI®-4282 78 D Polyurethane Casting Plastic

VFI®-4282 78 D Polyurethane Casting Plastic

VFI-4282 78 D Polyurethane Casting Plastic is a high-impact urethane plastic with high heat deflection and tensile strength. This material works well when vacuum-degassed and pressure-potted to provide a repeatable, uniform, void-free cast. It is a multi-faceted plastic capable of being used in rapid prototyping, production parts, and equipment housings for large part runs. VFI-4282 has a working time of 4-6 minutes.

VFI-4282 78 D Polyurethane Casting Plastic is a high-impact urethane plastic with high heat deflection and tensile strength.

Features & Benefits

  • Usable in platinum-cured silicone, metal, or prototyping urethane molds
  • High heat deflection temperature (HDT) at 198.5°F (92.5°C @ 66 psi)
  • Neutral color for easy priming and top coat application
  • Excellent processing and demold times at 1-2 hours
  • Non-mercury based, TDI-free, MOCA-free, odorless polymer

Instructions for Use:  

Mold Preparation  

For any molding applications, release agents are recommended to extend the life of the mold, and when using prototyping urethane molds, they are required. We do not recommend using heated molds or any mold over 120°F because it will cause an uneven cure. 

Casting Process  

Before each use, premix the B side (Poly) material once daily, ensuring extra moisture and air are not introduced into the material. We recommend preparing a suitably sized container with at least 2/3 of headspace for vacuuming degassing. Pour the measured A side into the container, then pour the measured B side into the same container. Mix until uniform with a hand or power mixer. Ensure mixing, vacuum degassing, and pouring are all complete before the end of the pot life.  

VFI-4282 78 D Polyurethane Casting Plastic cannot be poured less than a quarter inch thick at room temperature; otherwise, the part may not create the necessary exotherm to fully cure. If thinner pours are desired, elevate the mold and molding temperature to 115°F. 

Once the material has initially cured for 16 hours at room temperature, we recommend heat curing at 150°F for 24 hours to achieve full physical properties. Without post-curing in an oven, physical properties will be delayed until after seven days, and they may never fully develop.  


*Always read the safety data sheet before working with chemicals  

Use chemicals only as directed and for their intended purpose. Do not dispose of chemicals down the drain. Most chemicals must be disposed of as hazardous waste. 

PPE to avoid all unnecessary exposure:  

  • Eye protection – wear approved safety glasses and any additional eye protection as necessary 
  • Hand protection – wear chemically resistant protective gloves (nitrile, butyl, or neoprene) 
  • Skin and body protection – wear suitable protective clothing 
  • Respiratory protection – in case of insufficient ventilation, wear suitable respiratory equipment. Respirator selection must be based on known or anticipated exposure levels, the hazards of the product, and the safe working limits of the selected respirator 

Product Limitations  

This product contains isocyanate, which may irritate the skin and is toxic if inhaled.  

  • Incompatible materials – A side: amines, strong bases, water, alcohols, and heavy metals. B side: oxidizers  
  • Conditions to avoid – A side: contamination with water; keep away from heat, ignition sources, and incompatible materials. B side: heat and incompatible materials 
  • Chemical stability – stable under normal storage conditions 
  • Reactivity & hazardous reactions – no dangerous reaction known under normal use
  • Hazardous decomposition products – may include, but are not limited to, oxides of carbon. Also, oxides of nitrogen and isocyanates for the A side 

Potential Health Hazards 

  • May cause respiratory irritation. A side material may also cause allergy and asthma symptoms or breathing difficulties.  
  • May cause stomach distress, nausea, or vomiting if swallowed.  
  • May cause skin irritation and sensitization: redness, edema, drying, defatting, and cracking. 
  • May cause eye irritation: discomfort, pain, excess blinking and tear production, marked redness, and swelling of the conjunctiva.  

*If you are experiencing any of these symptoms, seek medical advice or attention. Call a poison control center or doctor if swallowed. 

Application Methods:

  • Pour Pour

Available Packaging:

  • Drum
  • 5 Gallon