Materials Shelf Life Warranty

Materials Shelf Life Warranty

The shelf life of Smooth-On® material refers to how long it can sit on a shelf (either unopened or after opening) before it begins to lose its ability to function normally or not be usable at all. The shelf life of a material will vary depending on chemistry and variables like exposure to heat or air after opening.

RECOMMENDED - Buy Only What You Need; a common mistake is to buy too much and have material left over that goes to waste. Determine how much material you need for your current project and purchase only that amount. We offer an online material calculator that can help you determine how much you need; (https://www.smooth-on.com/support/calculators/).

RECOMMENDED - Use After Buying; try to use materials within a few weeks after purchasing. A common mistake is to buy material and not use it for months or even years.

RECOMMENDED - Use After Opening; some materials have a very limited shelf life, especially after opening, and should be used as soon as possible.

How can I tell when material was manufactured?

Smooth-On® uses a lot-number system to identify when a material was made and track units after they have left our factory. Lot numbers for Part A and Part B are located on the product labels. The first two digits represent the year. The second two digits represent the month. The remaining digits are for inventory control purposes. Example:
Part A Lot#: 1902XXX - Part A was made in February 2019
Part B Lot#: 1903XXX - Part B was made in March 2019

Use the guide below to determine the shelf life of a specific material


  1. Urethane Rubbers, Urethane Plastics, Urethane Coatings, Urethane Adhesives, Expanding Urethane Rigid or Flexible Foams
    Properly stored in a low humidity environment and at room temperature (73°F/ 23°C), Smooth-On® urethane products have a shelf life of 18 months from date of manufacture in unopened containers.
    Once opened, urethanes generally have a very limited shelf life. Use what remains as soon as possible. The Part A side (Yellow Containers) is the moisture sensitive side and can become moisture contaminated in a matter of hours depending on exposure. Re-seal the container immediately after dispensing. Moisture contamination may result in the urethane system bubbling or foaming when Part A is mixed with Part B.
    Extending The Shelf Life Of Unused Urethanes – After dispensing Part A into a measuring container, spray XTEND-IT™ Dry Gas Blanket into the container before securing the lid. XTEND-IT™ will effectively double the shelf life of the remaining product by neutralizing moisture-laden air that remains in your container. Follow directions before using. Nitrogen will have the same effect but is usually only available in large cylinders for industrial or production environments.
    Related How-To:Extending the Shelf Life of Urethane Rubber and Resin
    Urethane Rubber Accessories (Kick-iT™, SO-Flex™, Sun Devil™, etc.) Properly stored at room temperature (73°F/ 23°C), Smooth-On® urethane rubber accessory products will have a shelf life of 18 months from date of manufacture in unopened containers.
  2. Urethane Colorants (UVO™, SO-Strong™, Ignite™)
    Properly stored at room temperature (73°F/ 23°C), urethane colorants will have a shelf life of 18 months from date of manufacture in unopened containers.
  3. Platinum and Tin-Cured Silicone Rubbers
    Properly stored at room temperature (73°F/ 23°C), Smooth-On® silicone platinum and tin-cure rubbers will have a shelf life of 12 months from date of manufacture in unopened containers.
    Exception: OOMOO™ tin cure silicones have a shelf life of 9 months from date of manufacture in unopened containers. After opening, use what remains as soon as possible.
    Important: Elevated temperatures will drastically reduce the shelf life of silicone rubber. For example, silicone rubber stored at 80°F (27°C) will have a shelf life of less than six months. Material stored at 100°F (38°C) will have a shelf life of less than two months.
  4. Silicone Rubber Accessories (Thi-Vex™, PlatCat™, Silicone Thinner™, etc.)
    Properly stored at room temperature (73°F/ 23°C) silicone rubber accessories will have a shelf life of 18 months from date of manufacture in unopened containers.
    Exception: Sil-poxy™ has a shelf life of 12 months from date of manufacture in unopened containers. Exposure to air and elevated temperatures will drastically reduce the shelf life of Sil-poxy™. Reseal after use and store at 73°F/ 23°C.
  5. Silicone Colorants (Silc Pig™ and Silc Pig™ Electric)
    Properly stored at room temperature (73°F/ 23°C) silicone color pigments will have a shelf life of 18 months from date of manufacture in unopened containers.
  6. Polysulfide Rubber – FMC™ Series
    Properly stored at room temperature (73°F/ 23°C), Smooth-On® polysulfide rubber products will have a shelf life of 24 months from date of manufacture in unopened containers.
  7. Epoxies – Castable, Laminating, Coatings, Putties and Adhesives
    Properly stored at room temperature (73°F/ 23°C), Smooth-On® epoxy products have a shelf life of 24 months from date of manufacture in unopened containers. For Bell Spec certification, Metalset A4 shelf life warranty is limited to 12 months. For all other certifications, the warranty for Metalset A4 shall be 24 months.
  8. Alginates - Alja Safe™, Acrobat™, Alja Safe™ Breeze, Accu-Cast™ Materials
    Properly stored at room temperature (73°F/ 23°C) in a low humidity environment (below 50% RH), these products have a shelf life of 18 months from date of manufacture in unopened containers.
  9. Skin Safe FX Materials - Ultimate Blood™ Kit, Derma-tac™, Q-Ballz™
    Properly stored at room temperature (73°F/ 23°C), these products have a shelf life of 18 months from date of manufacture in unopened containers.
  10. Polymer Modifiers for Gypsum & Concrete
    When properly stored at room temperature (73°F / 23°C), duoMatrix™ and Forton™ systems will have a shelf life of 12 months from date of manufacture in unopened containers.
    Important: The latex component of these products must not be exposed to temperatures below 35°F (1.7°C). Product that is allowed to freeze is no longer usable.
  11. Buddy Rhodes™ Concrete Bag Mixes, Oxide Color Pigments, Concrete Sealers
    When properly stored at room temperature (73°F / 23°C) Buddy Rhodes™ systems will have a shelf life of 12 months from date of manufacture in unopened containers.
    Important: Bag mixes and oxide pigments must be kept dry. Moisture will render these products unusable. Sealers must not be exposed to temperatures below 35°F (1.7°C). Product that is allowed to freeze is no longer usable and should be disposed of.
  12. Release Agents (Aerosol)
    Properly stored at room temperature (73°F/ 23°C), Smooth-On® and Mann® Release Technologies Aerosol Release Agents have a shelf life of 24 months from date of manufacture in unopened containers.
  13. Sealing Agents and Release Agents (Liquids)
    Properly stored at room temperature (73°F/ 23°C), liquid sealing and release agents have a shelf life of 24 months from date of manufacture when stored at 73°F (23°C) in unopened containers. After opening, product that is not adequately resealed can evaporate. Make sure you re-seal securely after dispensing.
  14. Powder Fillers (Ure-fil™, Cast Magic™, and Quarry Tone™)
    At least 24 months from date of manufacture when stored at 73°F (23°C) in unopened containers. Important: Keep powder fillers dry.
  15. Holden's Latex Rubber
    When properly stored at room temperature (73°F / 23°C), Holden's Latex Rubbers will have a shelf life of 12 months from date of manufacture in unopened containers. Important: Latex must not be allowed to freeze.