Sand the area to be joined with fine sandpaper, steel wool or emery paper to remove any surface oxidation or corrosion. Wipe away the dust with a damp cloth.
Wash the metal pieces with trisodium phosphate (or another industrial-strength cleanser) if they have had oil or other contaminants on their surface. These cleansers are powerful corrosives, so wear protective gloves and rinse the area with clean water when you're done.
Dry the area with a clean, lint-free cloth.
Squeeze equal amounts from the two tubes of epoxy into a disposable bowl or plate. Mix them thoroughly with a stick or coffee stirrer to form the adhesive.
Apply the adhesive to the areas that you wish to be bonded. Press the metal pieces together firmly, and use adjustable clamps to hold them in place. Different brands of epoxy mature at varying rates, but most require 24 hours' curing time.
Remove the clamps and sand away any excess epoxy for a finished, professional appearance.