A wear sleeve having tapered ends is secured to a drill pipe by placing tapered split seal rings adjacent the ends of the sleeve to seal the annulus between the sleeve and pipe, introducing exothermically polymerically setting liquid epoxy plastics material into the annulus via a long elastomeric riser tube pushed into an inlet port in one seal ring until the epoxy rises well into another long elastomeric riser tube pushed into an exit port in the other seal ring, meanwhile heating the interior of the pipe within the sleeve to e.g. 150.degree. F. by blowing hot air through the pipe, and when the plastics material has set, rotating the riser tubes about their axes to break off the sprues, and removing the riser tubes and seal rings.