A new toe rail for an old warhorse.

 

A new toe rail for an old warhorse

By Hugh Owens

Article taken from Good Old Boat magazine: Volume 4, Number 3, May/June 2001.

Beefing up a retired racer with aluminum

Racing caused wear on toerails

My
mate, Karlene, and I looked long and hard for a sailboat suitable for
world cruising that we could afford. I’ve become convinced that
boat speed is an important component of voyaging safety, so a major goal
in our search was to find a good old fast boat! In Tampa, Fla., we found
a neglected Cal 48 yawl.

This boat had been
raced hard and put away wet for too many years, and Karlene and I had
our doubts as we motored out into Tampa Bay for our sea trials. We hoisted
the baggy, tattered, but fully battened, main in a warm, 13-knot breeze,
and off she skipped at 7 knots. We unfurled the jib and were stunned as
she heeled gently and roared off at more than 9 knots. What fun! Concealing
our excitement, we made an appropriate offer that eventually was accepted.
In time, our Cal 48, renamed Koho, landed in Pocatello, Idaho, where we
started the refit.

If you examine enough
old classic plastic, you will find recurrent flaws and problems that span
a range of manufacturers. Our Cal 48 was no different. She was plagued
with stanchion and hull-to-deck leaks, as well as untabbed and broken
bulkheads, which are especially prevalent in older racers like Koho. Nevertheless,
we felt that our time and money would be better spent restoring a swift,
old, racing sailboat than a slower, more traditional, cruiser. We hoped
the payoff would be in sparkling noon-to-noon runs. The refit of Koho
has been total, but I’d like to focus on the structural solutions
changes that we made to the toerail and hull-to-deck joint.

Sealed holes

We stripped every piece of hardware off the hull and deck and sealed all
the holes with epoxy. Nevertheless, steady rains revealed persistent leaks
from one end of the boat to the other that were coming from the toerail.
Our toerail was an attractive piece of teak, 1 1/4 inches by 2 1/2 inches,
laid on edge and secured every 4 to 6 inches with 5/16-inch stainless
steel machine screws covered with teak bungs. The teak toerail also covered
the hull-to-deck lap joint. A first-generation mystery sealant bedded
the joint.

Near the cockpit,
a genoa track was bolted to the top of the toerail and secured by nuts
and washers below deck. Under the genoa track, virtually every bolt leaked
because of the substantial loads on the track from the huge sail. Reluctantly
we took the Sawzall to our beautiful toerail. We made attempts to save
the 4-inch stainless steel bolts, but most of them were severely corroded
in the anoxic environment of the leaky toerail. We then lifted the deck
off the hull, using dozens of wedges. Most of the bulkheads released the
deck with minimal fuss.

Once the joint was
free and the deck was lifted up a few inches, we could clean and blow
out the gap and apply 3M 5200 marine adhesive sealant, rebolt the hull
to the deck, and reattach the bulkheads with multiple layers of biaxial
cloth and epoxy resin on both sides of the bulkhead. Critical, highly
stressed bulkheads – such as the main bulkhead near the cap shrouds
and the ones under the lowers – were given additional layers of
fiberglass and epoxy.

Overkill, perhaps

Brackets used

Some of the brackets used, above. Clamping up prior to final mounting, below.

Clamping prior to final mounting

On the main bulkhead, a laminated deckbeam was epoxied and bolted to the
upper face of the bulkhead and epoxied to the underside of the deck. Stainless
steel carriage bolts from the top of the deck were then fastened through
this laminated beam. Strong? You betcha! Overkill? Perhaps, but I used
this technique on a 39-foot boat I built some years ago. During a bad
blow that boat was thrown sideways off a large wave and landed with a
shattering crash on her port side and sustained no structural damage.
The only downside to this technique is the time it takes.

The critical bulkheads
also received additional aluminum angle reinforcement where they contacted
the hull/deck joint, and bolts with backing plates and/or washers were
placed around the perimeter of the bulkhead to mechanically reinforce
the joint.

We next turned our
attention to strengthening and sealing the hull-to-deck joint. The upper
hull and decks on these Cals are thinly constructed, in keeping with their
racing heritage. We concluded that the only feasible fix was to fiberglass
the joint from the outside. To do this, the watertight but rough-appearing
hull/deck joint was faired with filled epoxy and sanded, then multiple
overlapping layers of biaxial cloth and mat were laid over the hull and
deck joint to a thickness of nearly a quarter-inch. More fairing, compounding,
and sanding was done to ease the transition between old and new glass.

Prohibitive cost

The next task was to design and build a new toerail. We looked at many
options. Commercial aluminum toerail was feasible but the cost was prohibitive
and what about all those holes every few inches in our now watertight
deck? Hal and Margaret Roth, on Whisper, used a clever method detailed
in their book After 50,000 Miles. They brazed Everdur (silicon bronze)
plates to the outside of the stanchion bases and then attached a 1-inch
by 4-inch teak toerail outside the stanchions to the Everdur plates. They
raised the teak 3/4 inch off the deck for water drainage. This seemed
like a good idea. Reapplying a wood toerail or bulwark remained an option,
but I wanted to avoid the leaks and maintenance associated with wood.

Years ago I worked
on commercial salmon boats in Alaska. I remembered how the aluminum gillnetters
used 1/2-inch by 2-inch flat bar stock as a toerail. It was welded edge-up
to an angle extrusion at the deck edge to stiffen that vulnerable area
from impacts with tenders and rough docks. I have long believed that aluminum
is the best material for cruising boats, but we were unable to find a
suitable aluminum boat that we could afford, and I began to wonder if
aluminum and fiberglass could be married during Koho’s refit, thereby
gaining the advantages of both materials.

We considered having
aluminum angle bent to match the outside curve of our hull and deck. We
had different angle extrusions bent at a local fabrication shop, but the
differing and constantly changing angles of the hull and deck made this
idea unworkable. We rejected welding as well.

Screwed and bolted

Scrrewed and bolted overlapping flat bar diagram

Eventually we settled on overlapping flat bar stock screwed and bolted
together. In some areas, the aluminum was prepped and epoxied together,
but the bulk of the construction used 3M 5200, 1/4-inch screws, and stainless
steel bolts attaching the plates to each other and to the hull. The most
useful and crucial part of the design is the 1/2-inch by 2-inch flat bar
stock that becomes the toerail. The sections are 12 feet long with 1/8-inch
gaps on the ends for expansion in the severe climatic changes we experience
in the Rockies. The toerail is stiffened at the joints where these flat
bar sections meet with brackets made from 1/4-inch aluminum angle, bandsawed
and sanded to a pleasing shape, and bolted to the toerail and deck using
oversized holes.

Holes are drilled
in this flatbar in key areas in a manner similar to the commercially available
perforated aluminum toerail. The toerail is supported at about 3-foot
intervals by the support brackets. Every other support bracket has a stanchion
base. Bolts fasten through the stanchion base, toerail bracket, and the
deck to aluminum backing plates beneath. Once bolted or tapped and fastened
together with machine screws and 5200, the whole assembly is astonishingly
stiff and robust.

After installing the
toerail, we attached a 1/4-inch by 4-inch aluminum plate to the hull so
that it fit directly under the toerail and in contact with it. This served
to cover the fiberglass overlap and strengthen the joint. We called this
piece the “hull plate.”

Rigid
structure

A final 1/4-inch by 2-inch flat plate was tapped and screwed to the toerail
above and the 1/4-inch by 4-inch hull plate below. This effectively joined
the toerail to the hull plate, making a very rigid structure that could
not have been cold formed in place if it had been a single piece.

A 3/4-inch by 2-inch
section of white UHMW (ultra-high molecular weight) polyethylene was fastened
with flat-head machine screws into tapped holes in this bar to form a
rubbing strake.

Tapping the aluminum
allows replacement or repair of the UHMW in the future. I considered wood,
aluminum, and PVC. We felt that UHMW offered a durable material that was
a more friendly surface against the tender topsides of fellow yachties.
I have high regard for UHMW. I’ve used it wherever friction needs
to be reduced. For example, I lined a chute with UHMW to feed our anchor
chain into the chain locker. The anchor chain glides into the locker as
if sliding on Teflon. We also used it in front of our deck cleats in lieu
of deck chocks to reduce chafe on the lines.

The aluminum bar
stock and extruded angles that I used were alloy 6061, which is the normally
available alloy for extrusions. This 6061 is commonly used in aluminum
yacht and workboat construction, but it is best used in above-water applications.
It has less corrosion resistance than the true saltwater alloys such as
the 5000 series. We plan to paint the aluminum for the sake of an improved
appearance.

Plastic spacers

Plastic spacers keep copper alloys away from aluminum

We took great care to make sure no copper containing alloys came in contact
with the aluminum. Our stanchion bases are made of either bronze or 316
stainless steel. They were made locally and they have a thin plastic (UHMW)
spacer isolating the stanchion bases from the aluminum bracket beneath.
The aluminum was painted with epoxy and linear polyurethane paint, and
while that is probably sufficient isolation from stainless, it’s
not that much more work to put in a little polyethylene spacer.
We attached the genoa track to a 2-inch by 2-inch by 1/4-inch length of
aluminum angle bolted to the inside of our aluminum toerail. This tactic
alone saved almost 100 holes through the deck. The aluminum angle was
bent using a plywood template by a local steel shop to conform exactly
to the curvature of the deck. The track angle is braced additionally every
4 feet with aluminum angle bolted to the deck and glued with 5200. The
finished track seems sturdy and superior to what it replaced.

In our most heavily
loaded bulkheads I placed the toerail aluminum angle brackets over the
interior structural bulkheads. Additional aluminum angle pieces were bolted
to the bulkheads and fastened to the angle toerail brackets above to tie
all these components together. The oversized deck cleats were bolted over
the bulkheads to the aluminum angles below. This is considerably stronger
than just using conventional backing plates.

The majority of vessels
I’d examined weren’t husky enough to cope with the boisterous
high-latitude offshore sailing conditions we expect Koho to encounter.
I think that aluminum construction is superior to all other boatbuilding
methods if you want to wed lightness and strength. My concept during this
refit was to use this superb material to strengthen and stiffen an older
fiberglass sailboat, utilizing one of the most abundant elements in the
earth’s crust.

Hugh, an anesthesiologist
in Idaho, is completing a total refit of
Koho, a 1966 Cal 48. He and his
wife, Karlene, formerly lived and sailed in Alaska on their 40-foot home-built
sailboat,
Endurance. They are preparing Koho for a voyage to Antarctica
and New Zealand.

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