Making Curved Railings - Continued
The Balustrade Railing
The lower balustrade railing was a different story. It was too
beefy to make with a router and a trammel arm. Instead, I
ordered the rails pre-bent by the manufacturer to the radius
required. The plans specified every radius on the house. Just
as with the spindle railing above, all I had to do was subtract
the distance from the edge of the deck to the center of the
posts. I then used that center measurement to order all the
Fypon manufactures straight balustrade railing embedded with a
3-inch-diameter steel pipe, so the typical 8-foot to 9-foot
spans between my posts were stiff and rigid. But Fypon’s
bent railing is formed around 3-inch PVC pipe, obviously
because PVC is easier to bend. I would have preferred steel
pipe in the radius sections, but with the 1/4-inch steel cable
supplied by the manufacturer, we were able to stoutly reinforce
the long spans.
Layout and cutting. We were
able to reuse the template we’d used for the spindle
railing because the radius was exactly the same. After marking
the top and bottom rails for each section, I used my miter saw
to cut the PVC embedded railing.
We laid out the balusters in the same manner, though the end
balusters were centered 2 1/2 inches in from the ends of the
railing because the spacing was 5 inches on-center (Figure
Drilling. Fypon balusters
are formed around 3/4-inch aluminum pipe, with the pipe
extending from the baluster by 1 to 1 1/2 inches. For drilling
the 3/4-inch holes in the railing, I experimented with several
types of drill bits on both the PVC and the steel-embedded
railings. I found that a 3/4-inch hole saw worked best on both.
I thought I’d have to stop the drill every three or four
cuts to clear the hole saw, but strangely enough, after two or
three holes, the compressed polyurethane inside the hole saw
acted like a spring and pushed out the waste, which we then
removed from the spinning hole saw with a small stick.
Figure 5.Balusters for the main railing were laid
out on 5-inch centers (left). A hole saw in a drill press made
for fast, accurate boring in the PVC radius railings (right) as
well as the steel-reinforced straight rails.
Assembling the Railings
Assembling the railings’ lower baluster was a little
trickier than assembling the spindle railings. We started at
the bottom rail, applying a liberal amount of Fypon adhesive
around each hole, then inserted the baluster (Figure 6). After
squeezing each baluster tightly against the railing, we
toe-nailed each one with 2 1/2-inch galvanized nails.
Next we added the top railing, starting at one end and slowly
working each of the balusters into its hole. Then we turned the
section upside down and used 5-foot Bessy clamps to hold things
together. The deep plastic jaws reached well over the railing
and didn’t mar the polyurethane. Once the entire section
was snugly clamped, we toe-nailed the top balusters, too.
I learned the hard way that I had to let the adhesive dry
before moving and installing the balustrade, because the
mixture of nails and polyurethane wasn’t strong enough to
secure the joinery. Once the adhesive dried, the pieces were
practically welded together.
Figure 6.When assembling the Fypon railings
(left), 2 1/2-inch galvanized finish nails, four in each
baluster, provided temporary security until the polyurethane
adhesive dried. Fitting the top rail (right) was tricky and
required two sets of hands because of the varying lengths of
the 3/4-inch pipe projecting out the end of the balusters. This
required finding and setting the longest dowels
Threading the Cable
Before starting the installation, we drilled a 1/2-inch hole
through each of the porch posts, exactly at the center of the
top railing, then passed a fish tape through each hole with a
pull string attached. We did the same with each section of the
radius railing, leaving a pull running through the hollow top
Starting at one end of the railing, we pulled the 1/4-inch
steel cable through each post and railing section until the
cable reached the opposite side of the last post. Then we
installed all the railings on L-clips, first applying a
generous amount of adhesive on each end.
After all the railings were mounted, we slipped several fender
washers over the dead end of the cable, secured the loose end
with a compression fitting, then pulled the cable tight with a
come-along until it sang like a piano string (Figure 7). In
fact, we had to release a little tension on the cable, because
it began to flatten the radiuses.
Figure 7.The PVC radius railings rely on a
tensioned steel cable for strength (top). A come-along provided
the necessary pull (bottom). The 3-inch hole where the cable is
cinched will be covered by a removable section of straight
railing, should the cable ever need retensioning.
Before starting the installation, I drilled a 3-inch-diameter
hole into the last post so we’d have room to tighten the
compression fittings. Once we were satisfied with the tension
on the cable, we locked it down but didn’t cut the cable.
Instead, we left the end long and looped it inside the
oversized hole. The next section was straight railing, which
didn’t need to be fastened with adhesive. The end of the
straight rail would cover the hole, but if the cable ever
loosened, I’d be able to access the cable to retighten it
by removing that section of straight rail.Gary Katzis a finish carpenter in Reseda, Calif., and author ofFinish
Carpentry, a JLC book.