Abstract: The agents comprise a mixture of(A) an adduct of a polyethylenepolyamine or a polypropylenepolyamine with an aliphatic or aromatic diglycidyl ether and(B) an aminoalcohol containing at least two aliphatic amino-hydrogen atoms, especially an adduct of a poly(aminoamide) with certain monoepoxides.(A) has the formula ##STR1## and (B) the formula ##STR2## where R.sup.1 represents a C.sub.2 -C.sub.60 hydrocarbon radical having amino or amido nitrogen in the chain, optionally substituted by amino or alcoholic hydroxy groups, being such that (B) contains at least two aliphatic amino-nitrogen hydrogen atoms,R.sup.2 represents ##STR3## R.sup.3 represents the residue (mol. weight 56 to 5,000) of an at least dihydric alcohol or phenol,P is an integer of average value 1 to 1.5,q is an integer of 1 to 5,R.sup.4 represents a hydrogen atom, C.sub.1 -C.sub.3 alkyl, phenyl, cresyl, chlorophenyl group, or a group R.sup.5 OCH.sub.2 --,R.sup.5 represents a C.sub.1 -C.sub.