Metering Pumps

WEST SYSTEM Epoxy Metering Pumps are calibrated for accurate metering of WEST SYSTEM Epoxy Resin and Hardener at the proper mix ratio, while eliminating mess and guesswork. The correct epoxy resin to hardener ratio is important to ensure that the epoxy reaches its full potential for cured physical properties. Our pumps come in a range of capacities suitable for every epoxy user, whether you use epoxy only occasionally for small projects or use great quantities of it daily in a major manufacturing operation.

300 Mini Pumps - epoxy metering pumps
300 Mini Pumps

306-23 epoxy metering pumps
306-23 Model A Metering Pump (3:1)

306-25 epoxy metering pumps
306-25 Model A Metering Pump (5:1)

306-Model A Rebuild Kit for 306 epoxy metering pumps
306-Model A Rebuilt Kit

303 Positive Displacement Pump (3:1) - epoxy metering pumps
303 Positive Displacement Pump (3:1)

305 Positive Displacement Pump (5:1) - epoxy metering pumps
305 Positive Displacement Pump (5:1) for WEST SYSTEM Epoxy Resin and Hardener

320 Small Batch Epoxy Scale
320 Small Batch Epoxy Scale

Why Use Epoxy 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 epoxy in small batches, mixing several ounces at once. The most popular epoxy metering pumps are 300 Mini Pumps. They get the job done 95% of the time. For very small jobs requiring tiny amont of epoxy, count on our 320 Small Batch Mixing Scale. For larger projects, you may need a larger pumping system such as the Model A Epoxy Metering Pump.

Epoxy Metering Pumps for Fast Dispensing

Our WEST SYSTEM Positive Displacement Pumps dispense epoxy faster than any pump we’ve ever offered. Positive Displacement Pumps work by trapping a fixed amount of resin and hardener then forcing (displacing) that trapped volume into the discharge pipe.  This offers improved epoxy pumping performance because changes in viscosity due to temperature change do not affect their performance.

Our epoxy metering pumps dispense epoxy at either a  3:1 ratio (for use with blush-free 207 Special Clear Hardener or 209 Extra Slow Hardener) and is easily identified with a red base. The 305 Positive Displacement Pump is calibrated for 5:1 ratio epoxies (with 205 Fast Hardener or 206 Slow Hardener) and has a blue base.

For more on mixing epoxy in large volumes (with or without epoxy metering pumps). read Big Batch Mixing Methods at Epoxyworks.