This may be required where a surface needs to be trued, corrected for fit to a mating part, needs to retain oil ( usually on a freshly ground surface ), or to give a decorative finish.
12.
A thin coating of Prussian blue is applied ( usually with a paint brush ) on the " insert " regardless of the shape or contour of the mould or tool before the matching is done with the mating part.
13.
"' Spiral welding "'is a process where a continuous full penetration MIG weld overlay is used to rebuild damage from wear, erosion, corrosion or cracking, or to increase the dimensions of a component to match an increased dimension on a mating part.
14.
The problem, in short, is that two mating parts ( lets say a jar and a lid ) normally fit fine, but when the jar is at the wide end of it's tolerance and the lid at the narrow end of the tolerance, they don't fit.
