Method for preparing a hydrogen tank including at least one sealing layer of a composition including at least one polyamide P1, and at least one base in order to provide the tank with at least one opening, wherein the method includes: providing of at least one base, the at least one base being covered by at least one layer of a composition including at least one adhesion primer; preparing the at least one sealing layer; fastening the at least one base to the at least one sealing layer.