Restoring columns on a New Orleans façade is anything but the Big Easy
Erika Marks Brauner
Wednesday, April 02, 2008
In the moisture-rich city of New Orleans, termites and rot can bring even the grandest Uptown mansion to its knees if left to the elements too long. So when the homeowners of a 19th century Greek Revival in the Garden District of the Crescent City wanted to restore its front façade, they knew that many of the double gallery's original cypress columns would need major repair.
Historic Columns-Something Old, Something New…
After assessment of the existing cypress columns, the homeowner and crew determine that new columns will be constructed by piecing salvageable parts of the original columns with new pieces, to be milled by a local craftsman. Once the composite columns are assembled, new Spanish cedar collars are bonded to the top and base of the column shafts, but the ends of the flutes have to be recreated to make the transition from the columns to the collars look seamless. The team of Milton Freewater, a New Orleans construction company, chooses to use the pairing of a router and chisel, then a three-part epoxy system, typically employed in boatbuilding for its strong defense against moisture and its ease in feathering.
Creating the Basic Shape
The tips of the flutes are roughed out using a handmade jig with a core box bit that rides along the valleys of the adjoining flutes. A gouge chisel is then used to further carve the flute tip's shape made by the router. The goal is not to define the finished shape-that's what the epoxy will do-but rather to create a sufficient hollow for the epoxy to be built up on. Nicks and gouges are to be expected and can be easily covered with the epoxy.
Applying the epoxy
The epoxy is applied for two reasons: one, to fill in any gouges left by the router and the chisel, and two, to create a seamless transition between the new collar and the column shaft.
First, equal parts of the Epoxy Resin and Slow Hardener are mixed. Once these are mixed well, the third ingredient, the Microlight fairing filler powder, can be mixed in (a good fistful of the fairing filler for three parts each of Resin and Hardener). Small amounts should be mixed at a time-no more than three squirts of each Resin and Hardener. To allow for maximum flexibility, the epoxy mixture should have a molasses-like consistency. The epoxy should be applied modestly, filling in any gouges or gaps, and shaped as closely to the wood as possible. Even though the epoxy is relatively easy to sand down, it's a good idea to minimize build-up. Especially on the column tops, because no matter your biceps, endless sanding will take its toll on your arms.
The epoxy is dry within a few hours. The hardened compound can be sanded with 60 grit, then smoothed further with 220. A piece of rubber piping, the same width of the flute, can be used as a form to wrap sandpaper around and slid up and down the flute. A turning motion is used to shape the top, but use care not to overextend the edges and distort the fillet, or the lines of the two joined pieces won't read as continuous. The hardest part of the shaping can be at the round flute tip. The end of a rubber form can be used, or a piece of sandpaper rounded over your thumb will follow the curve as well.
Once the flutes are sanded smooth, prime the surface immediately to protect the bare wood. A primer coat will also make it easier to see what areas need additional shaping or filling.
Sidebar - Moisture Rots
There is no question that the high content of moisture in the air and in the soil of New Orleans (the result of being 8 feet below sea level) contributes to much of the city's architectural decay. One way to combat the effects of water is to make sure it doesn't have an opportunity to pool on surfaces, which will result in moisture damage over time. Even though cypress is highly resistant to rot, care should still be taken to avoid testing its durability. After the flute tips are sanded and primed, go around with a cup of water to the columns that sit under possible drainage spouts. Spill a few drops on each flute tip at the base of each column and make sure the droplets spill down and out, rather than pool. Standing water invites rot, so where the drops pool, go back and shape the flute ends further to ensure that water will drain.
Or as a cutline:
One last check. After the flute tips are sanded and primed, go around with a cup of water to the base tips on columns that sit under possible drainage spouts. Spill a few drops on each flute tip and make sure the droplets spill down and out, rather than pool. Standing water invites rot, so where the drops pool, go back and shape the flute ends further to ensure that water will drain.
Cutlines:
Carving out the new flute tips is a two-part process. First, a router with a core box bit, set up on a handmade jig, scoops out the basic form. Second, a gouge chisel with a curved tip is used to further define the shape of the flute.
The flutes get their final shaping from the epoxy. A mix of resin, hardener and fairing filler is placed in the flute ends and smoothed along the curve of the flute to give it its shape and to cover any gouges the router and chisel may have left behind.
Sanding on a curve. Several hours later, once the epoxy is dried, the tips can be sanded to their final shape. The goal is to leave the tips smooth and their curves well-defined, and in line with neighboring tips.
Thumbs up. A sand-papered thumb makes a great jig for smoothing out the hollow.
Ideas for Art:
-A diagram of Corinthian column parts to include flute, fillet, capital, shaft, and base
-A breakdown of the needed tools, details of the router jig.
