Composition for a curable substance for fixing purposes, comprising an epoxy component (a), which contains curable epoxides, and a hardener component (b), which comprises (i) a Mannich base formulation obtainable by reaction of one or more specific amines with phenols and aldehydes, the specific amines being those of the formula wherein "CYC" is a monocyclic saturated ring having from 3 to 12 ring atoms or a condensed dicyclic saturated ring system having from 6 to 12 ring atoms, wherein in each case the ring atoms are selected from 0 to 2 nitrogen atoms, 0 to 1 oxygen atoms and 0 to 1 sulfur atoms and from carbon atoms; X is CH 2, wherein for each group - n -NH 2 one X can be NH, O or S, with the proviso that in the case of an X = O or S, in the group - n -NH 2 in question n is at least 2 and the O or S is not bonded directly to a nitrogen atom and in the case of one X = NH, n is at least 2 and the X = NH is bonded neither directly to a nitrogen ring atom nor to a nitrogen atom present in the group - n -NH 2 in question; n is from 0 to 5, with the proviso that at least in one of the groups - n -NH 2 n is from 1 to 5; and m is a whole positive number greater than or equal to 2, especially 2 to 3; or salts thereof, and/or (ii) mixtures of styrenated phenols with one or more low molecular weight amines, which are di- or poly-amines, or salts thereof. (i) a Mannich base formulation obtainable by reaction of one or more specific amines with phenols and aldehydes, the specific amines being those of the formula wherein "CYC" is a monocyclic saturated ring having from 3 to 12 ring atoms or a condensed dicyclic saturated ring system having from 6 to 12 ring atoms, wherein in each case the ring atoms are selected from 0 to 2 nitrogen atoms, 0 to 1 oxygen atoms and 0 to 1 sulfur atoms and from carbon atoms; X is CH 2, wherein for each group - n -NH 2 one X can be NH, O or S, with the proviso that in the case of an X = O or S, in the group - n -NH 2 in question n is at least 2 and the O or S is not bonded directly to a nitrogen atom and in the case of one X = NH, n is at least 2 and the X = NH is bonded neither directly to a nitrogen ring atom nor to a nitrogen atom present in the group - n -NH 2 in question; n is from 0 to 5, with the proviso that at least in one of the groups - n -NH 2 n is from 1 to 5; and m is a whole positive number greater than or equal to 2, especially 2 to 3; or salts thereof, and/or "CYC" is a monocyclic saturated ring having from 3 to 12 ring atoms or a condensed dicyclic saturated ring system having from 6 to 12 ring atoms, wherein in each case the ring atoms are selected from 0 to 2 nitrogen atoms, 0 to 1 oxygen atoms and 0 to 1 sulfur atoms and from carbon atoms; X is CH 2, wherein for each group - n -NH 2 one X can be NH, O or S, with the proviso that in the case of an X = O or S, in the group - n -NH 2 in question n is at least 2 and the O or S is not bonded directly to a nitrogen atom and in the case of one X = NH, n is at least 2 and the X = NH is bonded neither directly to a nitrogen ring atom nor to a nitrogen atom present in the group - n -NH 2 in question; n is from 0 to 5, with the proviso that at least in one of the groups - n -NH 2 n is from 1 to 5; and m is a whole positive number greater than or equal to 2, especially 2 to 3; (ii) mixtures of styrenated phenols with one or more low molecular weight amines, which are di- or poly-amines, or salts thereof.