A method for sealing, coating or/and aerodynamic smoothing of at least one connecting element that protrudes from a surface with a sulfur-containing sealing compound where curing is initiated "on demand" with an energy input - referred to hereinbelow as a "SCOD sealing compound" - at at least one application site, especially on an aerospace component, with at least one nozzle element and with at least one irradiation unit, wherein i) at least one nozzle element, whose inner space is indirectly or directly connected to a sealing compound reservoir, i.e.: to at least one mixing apparatus, to at least one sealing compound tank, to at least one cartridge or/and to at least one cartridge magazine, contains a mixed, uncured or at least partially uncured SCOD sealing compound, which nozzle element is guided or/and slipped over the connecting element protruding from a surface and is therefore brought into contact with the surface or near the surface, ii) the inner space of at least one nozzle element is filled with SCOD sealing compound from a sealing compound reservoir, such as a tank, to at least such an extent, and is brought at least approximately in contact with the surface, that the connecting element protruding from the surface - referred to as the "application site" - is completely covered with SCOD sealing compound, wherein the SCOD sealing compound forms a sealing compound coating, which essentially has the shape of a sealing compound cap, of a coating or/and of a mound-shaped elevation, iii) at least one nozzle element or at least a part of at least one nozzle element, if necessary, is raised from the surface with the sealing compound coating, and iv) the curing of the SCOD sealing compound 1.) is initiated by at least one irradiation unit through energy input into a sealing compound coating, such as by irradiating with high energy radiation and 2.a) therein or/and thereby the release of a latent catalyst is initiated or 2.b) therein or/and thereby the direct activation of at least one reaction component is effected, so that the mixed SCOD sealing compound subsequently cures or/and cures further, wherein steps i) to iv) are performed with an automatic apparatus, wherein at least two application sites are processed simultaneously or are processed simultaneously in succession. i) at least one nozzle element, whose inner space is indirectly or directly connected to a sealing compound reservoir, i.e.: to at least one mixing apparatus, to at least one sealing compound tank, to at least one cartridge or/and to at least one cartridge magazine, contains a mixed, uncured or at least partially uncured SCOD sealing compound, which nozzle element is guided or/and slipped over the connecting element protruding from a surface and is therefore brought into contact with the surface or near the surface, ii) the inner space of at least one nozzle element is filled with SCOD sealing compound from a sealing compound reservoir, such as a tank, to at least such an extent, and is brought at least approximately in contact with the surface, that the connecting element protruding from the surface - referred to as the "application site" - is completely covered with SCOD sealing compound, wherein the SCOD sealing compound forms a sealing compound coating, which essentially has the shape of a sealing compound cap, of a coating or/and of a mound-shaped elevation, iii) at least one nozzle element or at least a part of at least one nozzle element, if necessary, is raised from the surface with the sealing compound coating, and iv) the curing of the SCOD sealing compound 1.) is initiated by at least one irradiation unit through energy input into a sealing compound coating, such as by irradiating with high energy radiation and 2.a) therein or/and thereby the release of a latent catalyst is initiated or 2.b) therein or/and thereby the direct activation of at least one reaction component is effected, so that the mixed SCOD sealing compound subsequently cures or/and cures further,