The invention relates to a solution in particular for the pre-treatment of a surface, containing, preferably consisting of: I) at least one first silane of formula (I) with R1, R2, R3 independently selected from the groups methyl, ethyl, 2 methoxyethyl, propyl, i-propyl, butyl, benzyl, wherein m=0 or 1, n=3 to 12, p=1 or 2, and for p=1, Y=a functional group selected from the groups (meth)acryl, (meth)acryloxy, mercapto, ureido, —NH—CH2—CH2—NR4R5, —NR4R5 (with R4 and R5 independently selected from the groups H, alkyl, phenyl, benzyl, cycloalkyl), or for p=2, Y=NH; II) at least one second silane of formula (II) with R1, R2, R3 independently selected from the groups methyl, ethyl, 2 methoxyethyl, propyl, i-propyl, butyl, benzyl, wherein m=0 or 1, R8=H, alkyl, phenyl, benzyl or cycloalkyl; III) at least one alcohol; and IV) water.