VFI®-4172 75 D Slow Casting Plastic

VFI-4172 75 D Slow Casting Plastic is a hard, 100% solids, polyurethane plastic with a convenient 1:1 mix ratio by volume and high tensile strength. A longer pot life provides you with ample time to pour and process the material, which is great when pouring larger castings. The slow cure allows for pours at least ½” thick. This material is highly functional and easily machined with CNC or woodworking equipment. VFI-4172 is made to be poured and cured at room temperature for easier processing. 

VFI-4172 75 D Slow Casting Plastic is a hard, 100% solids, polyurethane plastic with a convenient 1:1 mix ratio by volume and high tensile strength.

Features & Benefits

  • Capable of casting at a thickness of ½ an inch
  • Long pot life for more working time
  • Produces durable and repeatable castings
  • Neutral color that can easily be painted and primed after full cure
  • Capable of being sanded and machined to a smooth and exact finish

Instructions for Use:  

Mold Preparation  

Using a release agent is recommended for any molding application to extend the life of the mold, and for prototyping urethane molds, it is a requirement. Heated molds are not recommended for this product or any mold over 120°F. Do not use a two-part closed mold.  

Casting Process  

The B side (Poly) must be premixed once daily before each use, being careful not to introduce extra moisture or air. The A side (Iso) does not need to be mixed. 

If vacuum degassing, prepare an appropriately sized container with at least 2/3 of headspace. Pour measured A side into the container and follow by pouring measured B side into the same container. Mix until uniform by hand or power mixer. Mixing, degassing, and pouring must all be completed before the end of the pot life. 

VFI-4172 does not require post-curing unless it is poured at less than 1/2”. If pouring thinner than 1/2 of an inch, it must be post-cured at 150°F for a minimum of 2 hours. Regardless of thickness, it will reach full properties within 7 days of curing.  


*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 exposures:  

  • 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: water, alcohols, amines, bases, and acids. B side: oxidizers 
  • Conditions to avoid – heat and incompatible materials  
  • Chemical stability – stable under normal storage conditions  
  • Reactivity & hazardous reactions – no dangerous reaction known under normal use
  • Hazardous decomposition products – A side: carbon monoxide, carbon dioxide, nitrogen oxides, hydrocarbons, and HCN. B side: may include, and are not limited to, oxides of carbon 

Potential Health Hazards  

  • May cause stomach distress, nausea, or vomiting if swallowed.  
  • May cause respiratory tract irritation. A side may cause allergy and asthma symptoms or breathing difficulties.  
  • May cause skin irritation or sensitization: redness, edema, drying, defatting, and cracking.
  • Causes serious 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

Available Packaging:

  • Tote
  • Drum
  • 5 Gallon
  • 1 Gallon