VFI®-5216 16 PCF Semi-Flexible Polyurethane Foam

VFI®-5216 16 PCF Semi-Flexible Polyurethane Foam

VFI-5216 16 PCF Semi-Flexible Polyurethane Foam is a two-component, water-blown urethane foam that is compressible with good bounce back. The 16 pounds per cubic foot expanding foam has a slow enough gel time to be machine-injected or hand-poured into a mold or form. Its self-skinning capabilities allow it to create a smooth, uniform surface for an improved appearance. With the ability to overpack, this semi-flexible foam is formulated to fill cavities and prevent voids. VFI-5216 is capable of creating many different high-density parts and shapes for prototyping, form liners, manufactured stone, precast, and more.

VFI-5216 16 PCF Semi-Flexible Polyurethane Foam from VFI is a water-blown, self-skinning foam that can be poured or injected to make many parts and shapes.

Features & Benefits

  • Great rebound and strength allow the foam to hold its shape
  • Works as a backfill material to adjust the weight of a piece
  • Self-skinning capabilities create a surface that can be primed or coated
  • Convenient 1A:2B mix ratio by volume for quick and easy application
  • Fast final cure speed for a quick turnaround on parts

Instructions for Use:

Mold Preparation

Porous materials such as natural stone, wood, and concrete must be sealed and released to prevent unwanted adhesion. Molds must be dry and coated with a release agent to extend the life of the mold. The mold must be strong enough to hold shape if subject to packing pressure. For better results, you can use a heated mold up to 120°F to speed up the demold time. However, heating the mold will also decrease the pot life and final density. Compatible molds for casting include metal, urethane, epoxy, and platinum silicone.

Mixing, Pouring, & Curing

The material should be brought to a minimum temperature of 65°F before use. Premix the B side (Poly) until uniform before combining with the A side (Iso). Pour the measured B side into the measured A side and mix rapidly with a drill or power mixer. Move the mixer through the center until uniform. Transfer the mixture to a new container and mix again before use. The material must be completely mixed before the 30-second cream time (initial rise).

The material should be poured immediately into the lowest point of the mold or form. Allow space for the foam to expand. Avoid scraping material from the container while pouring, as this takes time, and the material may not be fully mixed.

Once poured, the mold should not be moved while the foam rises since movement could cause cells to collapse. To prevent deformation, allow the foam to remain in the mold or form until fully cured. VFI-5216 should be allowed to cure for at least 2 hours at room temperature before removing it from the mold. Thinner pours may require a longer cure time.


Clean application equipment with MEK or xylene before the foam cures. If the foam has cured, you can break it off the surface and wipe the rest off with xylene.


*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 tightly fitted chemical safety goggles or glasses. Wear a face shield if a splashing hazard exists.
  • Hand protection – wear chemical-resistant protective gloves to prevent all skin contact. Suitable materials may include chloroprene rubber (Neoprene), nitrile rubber (Buna-N), chlorinated polyethylene, polyvinyl chloride (Pylox), and butyl rubber, depending on the conditions of use.
  • Body protection – wear suitable protective clothing. Cover as much exposed skin as possible to prevent all skin contact. Suitable materials may include saran-coated material
  • 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

VFI-5216 contains isocyanate, which can be irritating to the skin and toxic if inhaled as particulate matter. Avoid prolonged breathing of vapors and repeated skin contact. It must be protected from freezing. It is not UV color stable and has no long-term UV testing. If needed for exterior use, the foam must be painted or sealed. It is not fire retardant and is unstable in water.

  • Incompatible materials – A side: acids, amines, alcohols, water, alkalines, strong bases, and substances or products that react with isocyanates. B side: none known
  • Conditions to avoid – A side: moisture and freezing. B side: heat and incompatible materials
  • Chemical stability – the product is stable if stored and handled as prescribed/indicated
  • Reactivity – A side: no corrosive effect on metal. Based on its structural properties, the product is not classified as oxidizing. B side: No dangerous reaction known under conditions of normal use
  • Possibility of hazardous reactions – A side: Reacts with alcohols, acids, alkalis, amines, and water with formation of carbon dioxide. Risk of bursting, exothermic reaction, and polymerization. Contact with certain rubbers and plastics can cause brittleness of the substance/product with subsequent loss in strength. B side: No dangerous reaction known under normal use
  • Hazardous decomposition products – A side: carbon monoxide, carbon dioxide, nitrogen oxides, hydrogen cyanide, aromatic isocyanates, and gases/vapors. B side: may include, and are not limited to, oxides of carbon

Potential Health Hazards

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

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

Application Methods:

  • Inject Inject
  • Pour Pour

Available Packaging:

  • Tote
  • Drum
  • 5 Gallon
  • 1 Gallon