By Mike DeNardo

PHILADELPHIA (CBS) —     It’s springtime.  That means it’s maintenance time for the city’s public statues.

The enemy of any bronze statue is acid rain.  That’s why the Association for Public Art has a spring maintenance program for thirty statues.

On this day, technician Karl Solmssen was cleaning Einar Jonsson’s statue of Viking explorer Thorfinn Karlsefni, along Boathouse Row.

“These bronzes are hollow,” Solmssen notes.  “They’re as thin as cardboard in a lot of places.  So they can actually get holes in them and completely corrode away.”

Public Art Association assistant director Laura Griffith says the statues are cleaned and a protective wax coating reapplied.

“He is now currently, as we observe him, buffing the wax coating so that the modeling on the sculpture is more apparent and beautiful,” she explained,  “and it makes it so that we can read the sculpture the way that the artist intended.”

The Thorfinn statue has stood alongside the Sedgeley Club boathouse since 1918.