Process for assembling two parts (100, 300; 50a, 50b; 600, 700) by overlapping of edges (1, 3; 5a, 5b; 6, 7), each part (100, 300; 50a, 50b; 600, 700) being constituted by a material chosen from a metallic and thermoplastic composite material, characterized in that it takes place according to the following stages: - producing at least one patch (2, 2a to 2d) comprising a substrate made of one-component epoxy resin incorporating a crosslinking agent, the resin being chosen, by selection of the radicals of the epoxy monomer resin and the crosslinking agent, between a two-phase resin partially polymerized by a limited contribution of energy producing adherence, then completely polymerized at the polymerization temperature by a corresponding contribution of energy, and a single-phase resin having chain polymerization at the polymerization temperature; - in a preparation phase, an edge (1; 5a; 6) of a first part (100; 50a; 600) on which the patches (2, 2a to 2d) are intended to be positioned is pierced beforehand along a sewing line facing these patches (2, 2a to 2d) and as a function of a predetermined positioning of said patches (2, 2a to 2d) for optical control purposes, then - positioning of the patches (2, 2a to 2d) along the edge (1, 5a; 6) of the first part (100; 50a; 600) by adhesion of the patches (2, 2a to 2d) along the sewing line of the first part (100; 50a; 600); - in the assembling phase, superposition of the edge of the other part (300; 50b; 700) over the edge of the first part (100; 50a; 600) so as to sandwich the patches (2, 2a to 2d) between the edges (1, 3; 5a, 5b; 6, 7); - attaching the edges (1, 3; 5a, 5b; 6, 7) to the patches (2, 2a to 2d) by a contribution of energy for complete polymerization of the patches (2, 2a to 2d), which become chemically bonded to said edges (1, 3; 5a, 5b; 6, 7); - cooling the edges (1, 3; 5a, 5b; 6, 7) of the parts (100, 300; 50a, 50b; 600, 700); - producing at least one patch (2, 2a to 2d) comprising a substrate made of one-component epoxy resin incorporating a crosslinking agent, the resin being chosen, by selection of the radicals of the epoxy monomer resin and the crosslinking agent, between a two-phase resin partially polymerized by a limited contribution of energy producing adherence, then completely polymerized at the polymerization temperature by a corresponding contribution of energy, and a single-phase resin having chain polymerization at the polymerization temperature; - in a preparation phase, an edge (1; 5a; 6) of a first part (100; 50a; 600) on which the patches (2, 2a to 2d) are intended to be positioned is pierced beforehand along a sewing line facing these patches (2, 2a to 2d) and as a function of a predetermined positioning of said patches (2, 2a to 2d) for optical control purposes, then - positioning of the patches (2, 2a to 2d) along the edge (1, 5a; 6) of the first part (100; 50a; 600) by adhesion of the patches (2, 2a to 2d) along the sewing line of the first part (100; 50a; 600); - in the assembling phase, superposition of the edge of the other part (300; 50b; 700) over the edge of the first part (100; 50a; 600) so as to sandwich the patches (2, 2a to 2d) between the edges (1, 3; 5a, 5b; 6, 7); - attaching the edges (1, 3; 5a, 5b; 6, 7) to the patches (2, 2a to 2d) by a contribution of energy for complete polymerization of the patches (2, 2a to 2d), which become chemically bonded to said edges (1, 3; 5a, 5b; 6, 7); - cooling the edges (1, 3; 5a, 5b; 6, 7) of the parts (100, 300; 50a, 50b; 600, 700); <EOS>