The process of setting in a patch to mask a superficial casting flaw:
1) casting flaw noted on the surface of the bronze (cross section);
2) the flaw is chiseled to create a geometric shape that is easily duplicated; an undercutting bevel is cut into the sides of the wall;
3) a metal patch is set into the flaw;
4) the patch is hammered and chased to fill the flaw and match the adjacent surface as much as possible; the repair is locked in place by the undercut of the bevel;
5) a similar process can be used to insert a plug to repair a flaw that extends through the entire thickness of the wall.