dovetail grout holder (mini rebar) for corners of tiled walls

In the bathroom, the walls are covered with ceramic tile. There are a couple of outside corners where special round-nose tiles weren't used; instead they just left a gap, and made the rounded corner by filling with sanded grout. After 35 years the grout tended to crack and fall out from those corners. So, I made these pieces with special settings in skeinforge, to have no shells, only very low-percentage infill, so that they are like trusswork, very porous. I epoxied them to the edges of the