WEST SYSTEM® Metering Pumps

Epoxy metering pumps ensure you're using the correct ratio of resin to hardener, crucial to epoxy performance. Depending on the hardener you select, WEST SYSTEM Epoxy is mixed at a ratio of five parts resin to one part hardener, or three parts resin to one part hardener. At the proper mix ratio, the number of chemically reactive sites in the resin balances the number of reactive sites in the hardener. The resin molecules are larger than the hardener molecules, and have few reactive sites, hence the 5:1 or 3:1 ratio. When the mix is stirred thoroughly, the resin and hardener molecules react to develop full strength. If the mix contains excess hardener, hardener molecules will remain unreacted in the cured epoxy, weakening it. They can also prevent subsequent paint coatings from setting up.

 

NOTE: Never add extra hardener in attempt to alter cure speed. This will only throw the resin-to-hardener ratio off, preventing the epoxy from reaching its full potential, and possibly even keeping it from hardening. Many people use epoxy in small batches, mixing several ounces at once. The most popular epoxy metering pumps are the WEST SYSTEM 300 Mini Pumps. They get the job done 95% of the time. For very small jobs requiring tiny amount of epoxy, we recommed using a scale. For larger projects, you may need a larger pumping system such as the 315 or 313 High-Capacity Pumps.