West System 105B Epoxy Resin with 205B Fast Epoxy Hardener and 300 Mini Pumps Set

West System 105B Epoxy Resin (126.6 fl oz)

This 105B Epoxy Resin is the base material on which all West System 105 System epoxy compounds are built. It is a clear, pale yellow, low-viscosity liquid epoxy resin. Blended with hardener at the proper ratio, it cures to a hard, solid plastic with superior physical properties. Based on which hardener you choose, it cures at a wide range of temperatures. Once cured, it forms a high-strength solid that is functionally waterproof, and highly resistant to moisture. The West System 105B Epoxy Resin is designed to wet out and bond with wood fiber, fiberglass, and reinforcing fabrics. It also bonds well with a variety of metals when mixed at the proper ratio with a West System Epoxy hardener.

No Strong Solvent Odor

105 Epoxy Resin is formulated without volatile solvents and does not shrink after curing. It has a relatively high flash point and no strong solvent odor, making it safer to work with than polyester or vinylester resins. Resin viscosity is approximately 1000 centipoise (cP) at 72-degree-F.

Thickening Epoxy

Modifying this epoxy with West System fillers creates an excellent structural adhesive or fairing compound. You choose the filler that suits your project. Epoxy thickened with adhesive (high-density) fillers makes structural bonds, bridges gaps, and fills voids. Epoxy thickened with fairing (low-density) fillers is easily sanded and shaped after it cures.

Great Coating Material

This epoxy is also a great coating material. With roller applications, it has excellent thin film characteristics, allowing it to flow out and self-level without fish-eyeing. By combining it with blush-free 207 Special Clear Hardener (sold separately), you can create a natural finish when coated with varnish. This is a good alternative that builds mil thickness quickly, saving time and effort. The results are long-lasting.

Epoxy’s Cure Stages

Mixing 105 Epoxy Resin with a hardener begins a chemical reaction that transforms the combined liquid ingredients to a solid. This period of transformation is the cure time. As it cures, epoxy passes from the liquid state, through a gel state, before it reaches a solid state.

Batch Size and Cure Speed

You need to know that in larger quantities, epoxy cures much faster. This is because epoxy generates heat as it cures and also cures faster at higher temperatures. This snowball effect increases until the epoxy cures—which in very large batches could take only a couple of minutes. Large pots of mixed epoxy can generate enough heat to cause a runaway exothermic reaction. This includes fumes, melting the mixing cup or even starting a fire. Spreading epoxy thin allows the heat to dissipate and slows its cure.

Epoxy Casting

West System Epoxy has a very low percentage of shrinkage. In fact, the standards used to calculate shrinkage of other resins (polyester and vinyl ester) aren’t used with West System because it shrinks so little to measure that way. When epoxy is used to fill holes drilled into wood, it will soak into the end grain. This might look like shrinkage, but it’s not.

West System Epoxy

Based on 105 Epoxy Resin, West System Epoxy is a versatile low-viscosity epoxy system. It is used for boat building, composite construction and repairs that require high-strength, waterproof coating, bonding, and filling. It readily wets out fabrics and porous materials, and is easily modified for a wide range of working conditions and applications. West System Epoxy is the world’s most reliable and widely used marine epoxy.

Clamping Force

Unlike traditional wood glues, West System Epoxy is stronger than wood. Because of this, it is beneficial to have some epoxy between the objects you are gluing together whether they are wood, fiberglass, or other materials. As long as the epoxy is contacting the entire surface of both substrates, no clamping pressure is needed.

West System 205B Fast Epoxy Hardener (27.5 fl oz)

The West System 205 Fast Hardener is a medium-viscosity epoxy curing agent. It is useful in a majority of bonding situations, and at lower temperatures. This hardener produces a rapid epoxy cure that develops physical properties quickly at room temperature. Mix it with West System 105 Resin (sold separately) in a five-part resin to one-part hardener ratio. The resulting cured epoxy is a rigid, high-strength, moisture-resistant solid. The combination of 105 Resin/205 Fast Hardener has excellent bonding and coating properties. The West System 205 Fast Hardener is formulated to cure well at temperatures as low as 40-degree-F (4-degree-C). There are several things you can do to ensure a full cure when using epoxy in low temperatures.

Pre-Warm the Resin and Hardener

Cold temperatures increase an epoxy’s viscosity, making it harder to dispense, mix and apply. Warming resin and hardener reduces their viscosity, so they flow easily through their dispensing pumps. To pre-warm, place the resin and hardener containers under a warming lamp or in a warm-water bath. Pre-warmed resins and hardeners will not cling as much to your mixing equipment. They’ll also blend more easily, ensuring thorough mixing. A warmer, lower-viscosity mixture flows smoothly during application and readily penetrates porous surfaces.

Dispensing and Mixing Epoxy in Cold Temperatures

Always dispense 105 Resin (sold separately) and 205 Fast Hardener at the proper mixing ratio. Never alter the amount of hardener because this can seriously compromise the epoxy’s ultimate strength. Optional West System 300 Mini Pumps come ready to dispense the correct ratio of resin and hardener. One full pump-stroke of resin for every one full pump stroke of hardener is all you need to remember.

Preparing Surfaces

Between applying coats of epoxy, prepare the cured epoxy surfaces. When coating at cold temperatures, the slower cure can result in a waxy/greasy film on the surface of the cured epoxy, called amine blush. Remove this byproduct of the curing process before you apply the next coat of epoxy. Amine blush is easy to wash away with plain water and a 3M Scotchbrite pad. Don’t let the water evaporate. Dry the surface with plain white paper towels. Don’t use rags, because they can contaminate the surface with laundry softeners and anti-cling ingredients.

Allow the Epoxy Extra Time to Cure

Allow the epoxy additional time to cure before you remove clamps or stress the joints. As a general rule, double the cure time for every 18-degree-F (10-degree-C) drop in temperature. Allow even more cure time when for bonding pre-stressed joints, bent laminations, or joints that will undergo high loads. Elevate the temperature of the partially cured epoxy. This can help the resin and hardener complete their cross-linking. It’s a good way to boost the epoxy’s physical properties, even after a week at cold temperatures.

West System 300 Mini Pumps Epoxy Metering Pump Set (3-Pack)

These 300 Mini Pumps from West System are designed for convenient and accurate metering of Group A, B, and C resin-based epoxy. This 300 Mini Pump Set contains one 105 Epoxy Resin Pump, one 205/206 Epoxy Hardener Pump, and one 207/209 Epoxy Hardener Pump. Pumps mount directly on the resin and hardener containers and eliminate the mess involved with measuring by weight or volume.

Calibrated for Precision

These pumps are calibrated to deliver the proper working ratio with one full pump stroke of resin for each one full pump stroke of hardener. 105/205-206 pumps deliver approximate 0.8 fl oz of resin/hardener with one full stroke of each pump. 105/207-209 pumps deliver approximately 0.9 fl oz of resin/hardener with one full stroke of each pump.

For Group A, B, and C Containers

Made of durable polypropylene, the Mini Pumps gives years of dependable service. As packaged, the pumps are ready to install on the Group Size B containers. A package of extension tubes for Group Size A containers is included with this pump set. Group Size C extension tubes are included with the 105-C Resin and 207-SC or 209-SC Hardener containers.

Accurate Metering

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.

Ratio Verification

The ratio of each pair of Mini Pumps is controlled by the installation of a clip, that limits the stroke (and volume) of one or both of the pumps. All Mini Pumps are carefully inspected during this operation and during packaging. But the final test of a pump’s performance can’t be made until it is actually pumping resin or hardener. The ratio verification test described in the instructions confirms that both pumps are dispensing the correct volume and that the ratio of resin to hardener is within a critical narrow range.

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.

Epoxy Metering Pumps for Fast Dispensing

West System Pumps dispense epoxy faster than any pump they’ve ever offered. These pumps work by trapping a fixed amount of resin and hardener then forcing (displacing) that trapped volume into the discharge tube. These offers improved epoxy pumping performance because changes in viscosity due to temperature change do not affect their performance.