The present invention provides a sol-gel composition which is dilutable with water in any proportion and is based on the reaction of at least the following components: (i) a glycidyloxypropylalkoxysilane, (ii) an aqueous silica sol having a solids content of >1% by weight, (iii) an organic acid as hydrolysis catalyst, and (iv) n-propyl zirconate, butyl titanate or titanium acetylacetonate as crosslinker, starting from a mass ratio of the solids mass of component (ii) to component (i) 0.75, a process for preparing it and its use, in particular as a sol-gel composition for corrosion control coatings, a corresponding corrosion control coat or primer coat, and articles equipped with such a coating.