Curable compositions are provided comprising (i) at least one epoxy resin as specified (ii) an epoxide hardener system comprising (a) a carboxylic acid anhydride, (b) a first amine having a melting point from about 30 C to about 100 C and containing at least one primary amine group; and (c) a second amine having a melting point of from about 50 C to about 180 C and having at least one primary amine group, wherein the first and second amines are selected such that they have a difference in melting points of at least 10 C and wherein the first and second amines are contained in minor amounts by weight as compared to the carboxylic acid anhydride; and (iii) a filler as specified. Also provided are compositions obtainable by curing the curable composition, the use of the curable composition for filling of voids in honeycomb structures and processes for filing voids in honeycomb structures.