Using two part epoxy as an adhesive is easy and effective. You will need the proper knowledge, the right tools, and safety equipment to complete properly. Two part epoxies are ideal for its high strength, can be used for multiple applications such as automotive, marine, and construction, and come in a range of curing times to suit a variety of needs.
Step 1 - Mix Epoxy
It is essential to wear a respirator, gloves, and safety glasses before working with epoxy. Mix both epoxy resin and hardener according to the manufacturer’s instructions. Use mini pumps that are sold with both parts of the epoxy. These pumps provide the exact mixture of both resin and hardener for the proper cure and full application of the product. Using a mixing stick, stir the mixture for two minutes into a clean plastic container such as a reused cottage cheese or butter tub.
Step 2 - Prepare the Surface
Be sure bonding surfaces are clean. If in doubt, clean each surface with acetone. Be sure surfaces are completely dry to get good adhesion from the epoxy. Epoxy products will also specify how to prepare different surfaces, such as different species of wood, metal, and other materials. Be sure to follow the manufacturer’s instructions for these applications.
Step 3 - Glue Surfaces
Dry fit the pieces to be bonded to ensure a tight fit. Using either the mixing stick or a stiff brush, apply the resin/hardener mixture as neatly as possible to both surfaces that are to be glued together. You can either use clamps or screws to secure the two surfaces together. Use rags or a metal scraper to remove excess epoxy that oozes out of the joints before it hardens. Using a clean piece of wood or the metal scraper, provide a seal of epoxy along with the joined pieces. This will also solidify the joint and lock out moisture, making the joint weatherproof for outdoor applications.
Step 4 - Sand
Be sure to allow the epoxy joints to dry completely before final sanding and finishing. Carefully read the manufacturer’s directions and be patient. Remove the clamps and sand with 80 grit sandpaper to ensure removal of the roughness of the epoxy finish. Work up to 180 grit, as you will want to establish a “tooth” with which the final coat of varnish can adhere. Clean off sanding sawdust with a clean cloth soaked in acetone or mineral spirits and allow to dry thoroughly.
Step 5 - Final Finish
Whether the final finish is of paint or varnish, several coats will be necessary for a satisfactory finish. If painting, be sure to use a good primer as an undercoat before applying a final paint finish. If using varnish, apply the first coat of 50% varnish and 50% mineral spirits. When this coat is thoroughly dry, apply the second coat of 75% varnish and 25% mineral spirits. Finally, apply a 100% coat of varnish when the previous coat is thoroughly dried. For an even smoother finish, rub the varnish coat out with steel wool.