4 Step Guide on How to Use Two-Part Epoxy Adhesive

If you’re looking for an adhesive that can be used on a variety of substrates, a two-part epoxy adhesive is a great option. Consisting of a resin and a hardener, two-part epoxy adhesives have an incredible bonding strength, and they can be used for bondy pretty much any substrate except for polymer and untreated plastic. But to get the optimal bonding strength from two-part adhesives, the mixing and application process has to be right. This article will provide a 4 step guide on how to use the adhesive the correct way. 

# Use The Right Materials 

Whenever you’re working with two-part epoxy adhesives, you want to make sure it does not come in direct contact with your skin. So take proper safety precautions to keep the substance away from your skin, particularly your eyes and mouth. Before you start preparing the adhesive, get a hold of these materials first:

• Disposable gloves
• Safety glasses
• Weight scale or volumetric cups
• Mixing stick (preferably metal)
• Part A and part B epoxies 

# Surface Preparation

Surface preparation is very important when using two part epoxies. It determines the bonding strength when the adhesive cures.  Make sure the surface on both the substrates where you’ll apply the adhesive are absolutely clean. If possible, wipe down the surface with a cleaning solvent or create light abrasions before applying the adhesive. This will ensure that the two substrates have been bonded properly. Be careful particularly of oil as it can entirely nullify the bonding process. 

# Mixing The Epoxies

Two-part epoxy adhesives are of many types, and there are several methods for mixing the parts. Here are three of the most common mixing methods.

Cartridge Mixing

Cartridge mixing is used for medium to large production runs. Two-part epoxy adhesives that require cartridge mixing such as the Plexus MA310 are pre-packaged in cartridges that are attached together. The advantage of cartridge mixing is that it does not require much additional work. When squeezed out their respective cartridges, the resin and hardener will mix at the outlet and this is enough to strongly bond substrates. Depending on the type of adhesive, the volume ratios of the quantity of resin and hardener contained in the cartridges can either be 1:1 such as with the Devcon DA291 or 1:2. 

Hand Mixing Method: Hand mixing is mostly used for prototyping or low-volume production, and is not recommended for preparation of medium to higher quantity. The best way to hand mix two-part epoxies is to first pour the resin into a mixing vessel, and weight to get its amount. Then the same amount of the hardener should be added. The important thing here is that the amounts of the two parts are matching. Once the two parts are poured together, use a stick to stir and mix them together for at least three minutes. Avoid whipping the material which could create air bubbles in the mixture. After the resin and hardener has been thoroughly mixed, it is ready for use. 

Meter mixing

Meter mixing is done using mixing equipment and this method is only used for high-volume productions. The most important thing in meter mixing is that the plumbing on the mixing equipment is compatible with the adhesive being mixed. Contact your epoxy manufacturer to confirm if any types of plastics or metals can negatively affect your epoxy. If you have this sorted, your adhesive will come out properly, ready for use. 

# Curing The Two-Part Epoxy

Two-part epoxy adhesives cure by exothermic chemical reaction when mixed properly. You can either let your adhesive cure at room temperature at a normal speed or accelerate the process with heat treatment. What is important is that you don’t apply any stress on the bonds before it reaches handling capacity. 

Conclusion

When properly mixed and cured, two-part epoxy adhesives can bond substrates at incredible strength. As long as you follow the steps mentioned above, you should be able to use the adhesives successfully for your application.