A large piece was broken off one of the buckets , and
small chunks were also worn off a number of buckets as shown in the
picture below. The large piece was welded back onto the bucket. The
other damaged buckets were built up by welding. Then the repaired
runner buckets were CNC machined at their tips to the designed profile.
The machined tips were finished by manual grinding and polishing. The
repaired runner was heat treated to relieve any heat stress from welding
and then checked for its dynamic balance.