Peeling back the years
For those who have been curious about whats really going on behind the plastic veil thats enclosed the Old Capitol for the past few months, its paint removal, coating removal, and wood repair. Although the building appears to be all stone, the columns and most of the cupola are made of wood. In the more than 150 years of the buildings life, the wood has been painted and repainted many times, but the old coats of paint have never completely been removed. Now the necessary job of removing those layers is under way.
The accumulated material is half to three quarters of an inch thick in some places, says Bulger, who is managing the restoration project. A lot of detail has been obscured. For example, the columns on the east portico have grooves called reveal lines that have been filled in completely and havent been seen for years.
The original layer is oil paint with sand embedded in it. Its a historic mixture that was designed to make wood look like stone. The technique was popular among Americas founding fathers. George Washingtons Mount Vernon and Thomas Jeffersons Monticello are both partly wooden structures painted with sand paint.
Removing the paint is more than a cosmetic task. An excessive buildup of paint can actually damage the structure underneath it.
Some of the paint accumulation is like plaster, Bulger said. Its essentially a pseudo-masonry over wood.
As the wooden structure shifts over time, the brittle encrustation of paint cracks. Once water seeps in, the paint peels and blisters further, requiring yet another coat of paint.
Its a constant cycle of maintenance, Bulger says.
The water problem gets more serious the higher up the building you go. The columns on the east portico have relatively plain Doric capitals sheltered by the roof, but the columns that support the cupola have much more detailed carvings and are more exposed. More crevices mean more opportunities for water to seep in and cause decay. Bulger expects that in these upper areas, there will have to be more replacement of wooden parts.
Its a delicate task, made more so by several factors: the buildings historic status, the presence of asbestos in the 1975 coating, fragile wood elements, intricate carvings, and the many materials used to protect the area in the past.
Old Capitol is a National Historic Landmark, says Ann Smothers, director of the Old Capitol Museum. (Thats a higher distinction than being on the National Register of Historic Places.) There are only 22 of these in Iowa. We are very careful to follow the guidelines that are the suggested national standards for historic preservation.
Once the old coats are removed and any damaged wood is restored, the building will get a new acrylic-based coating that will simulate the original sand paint.
Early Novembers looking good, Bulger says of the projects completion.
One element may take longer to finish: the ornate column capitals of the cupola. Ironically, the most intricate carvings on the building are also the farthest from the ground. These capitals were not made of solid wood blocks. Each is made of a plain wooden core with carved decorative elements nailed on. In order to comply with the guidelines for the restoration of a National Historic Landmark, the same kind of construction will be recreated to replace any decayed carvings. Skilled artisans will duplicate the individual carved pieces in a process that may take until January. Since the scaffolding will be down by then, the finished pieces will be applied using staging from inside the building or an aerial boom.
Then the campus will be treated to a view of Old Capitol as it hasnt been seen for generations.
I think well see a lot sharper architectural detail, Smothers says.
by Sam Samuels