Abstract: A method for the repair of the inside of installed conduits comprises the following method steps:drying of the inside of the line by flow-through of pre-dried compressed air,removal of interior coatings by flow-through of a mixture of compressed air and particles of an abrasive medium with a mean exterior diameter of >0.8 mm and a specific weight of >3.0 g.multidot.cm.sup.-3 in an amount of >1.0 g.multidot.m.sup.-3, the mixture flowing through the line with a mean speed of >10 m.multidot.s.sup.-1, relative to normal pressure, andblowing out the line by means of pre-dried compressed air.The adhesive resin utilized for the subsequent coating contains, among others, a solvent-free 2-component resin and at least 5% by weight of finely dispersed inorganic oxidic adhesives.