Damage to more complex fractures & castings requires Engineer to draw on his
skills and knowledge in coping with both the difficulties of the component’s
shape, its operation and its working environment.
This all has to be completed, often with a minimum downtime, frequently involving 24/7 working.
- Following the survey, a report is presented to the customer in
order to get the go-ahead for the repairs. The component is then
positioned, realigned and held firmly in position using clamps and
special fixtures.
- Using the Special Jigs, groups of holes are drilled across the
line of fracture to the tool depth of the casting.
- The holes are then joined by the use of pneumatic chisels to
conform to the shape of the Keys.
- The Key is a multi-dumbbell shaped section of a highly ductile
alloy that is manufactured in various sizes, these can be cut to
any length required, to suit the type of fracture.
- Individual layers of Keys are inserted in the apertures and
peened into a metal-to-metal condition, which becomes almost
integral with the parent metal.
- Holes are then drilled along the line of the fracture, then tapped,
and filled with studs, each stud biting into its predecessor, resulting in a pressure-tight join that restores rigidity to the casting.
- A stud is an important aspect of the Metal Stitching process,
bearing in mind that pressure repairs are often required.
- The studs are then run down until the heads shear, the
remaining rough metal being removed by pneumatic chisels.
- The whole repair is ground over until smooth
- Then it’s the final coat of paint