Aluminum or Steel Sailboats

tart -->2. Long life
Most sailboats are fiberglass these days, but ifOn the face of it, both steel and aluminum should
you are looking for a really strong sailboat, youlast a long time, and both need some attention.
are likely to choose steel or aluminum. Fiberglass isBoth can suffer from galvanic corrosion in salt
fine for normal use, but if you are going crosswater - especially in marinas - so you need more
oceans, or give your sailboat a hard life, metal issacrificial anodes than with fiberglass, and you
best. They are also good materials if you want toneed to renew them regularly. Aluminum is at a
get your own design of sailboat built.slight disadvantage in this respect - you must
The reason aluminum or steel are best is thatmaintain good anodes, but as these usually last
metals are both strong and stiff, and when hitmore than a season this is not a problem.
really hard, they bend - fiberglass and even theAluminum panels that are exposed to the
most advanced composites will break, and evenatmosphere form an oxide film automatically, and
shatter. Then the sailboat will almost certainly sink.this prevents further corrosion. So long as the
A sailboat with a dent in the hull can keep going.panels are dry, they do not corrode. Therefore, it
There are other advantages, too. Fiberglass boatsis best to leave most of the hull unpainted, and to
usually have separate keels that are bolted incoat the decks with non-slip panels - these are
place. The bolts 'work' in the retaining holes in thelike rubber mats that are bonded in position -
hull, enlarging then slightly, and after a few yearsrather than non-slip paint for example.
you are likely to get leaks. Worse still, if youWith a little care, an aluminum hull will last a very
press your sailboat really hard, the bolts canlong time. Steel is very different because it is
break,and you lose the keel. This happens quitealways trying to corrode or rust away. It must
often in racing, and can happen to cruisingbe treated, then coated to give it protection. It is
sailboats as well.usually easy to see what is happening outside, and
The keel of a steel or aluminum boat is formedkeep the hull in good shape, but not so easy to
as part of the hull, so it cannot come off - andsee what is happening in the bilges, and behind
the ballast of lead or steel is encapsulated inside,lockers and elsewhere. Almost always, after a
where it cannot move.few years, a steel hull will start to corrode on the
If you are looking for a 20-28 foot sailboat toinside, owing to condensation or water getting
cruise around rivers, estuaries and a little offshoreinside. Therefore, the steel boat is not so likely to
cruising, then fiberglass is fine. But if you want tolast a long time without giving some trouble -
go further, or you want your boat to be of aunless it has very thick panels - like a ship, in
particular design, choose aluminum or steel. Manywhich case it will be very heavy.
firms offer excellent designs for metal sailboats,Expensive to Repair
and some offer sets of panels that you weldWhen steel starts to rust badly, it costs a lot of
together - or have welded together - usuallymoney to repair. I have met several people who
complete with instructions.have had problems with steel sailboats. One
Twenty years ago, it was much easier to weldcouple I knew spent six months, working every
steel than aluminum, but with modern welding setsday, to remove the rust from the hull of their
and alloys, aluminum can be welded easily withsteel sailboat. Fortunately, the hull was thick and
just a little training - hours not weeks. Therefore,had been well protected so it remained sound.
more and more sailboats -and smaller motorOne sailboat that was about ten years old was
boats - are being made from aluminum.found to have rusted badly through the whole
But the next question is: Should I choose steel orhull- and needed repairing extensively, with new
aluminum?panels. The boat was worth about $30,000 in
The things to be considered are:good condition, but it would cost $20,000 to strip
1. Weight and weight distributionthe boat out for welding and then to refit it. On
2. Long lifetop of that the welding repairs would cost
3. Maintenance$10,000. In other words, the boat was almost
1. Weight advantage of aluminumworthless.
Steel is stronger than aluminum, but this is not theAnother man I met had bought a 32 foot steel
advantage it seems with a sailboat because if thesailboat which was only a few years old. On the
panels of the hull are too thin, they are difficult tomaiden voyage, he found water in the bilges
weld without distortion, and you will end up with awhich he discovered was leaking through the hull.
hull with wavy panels. The minimum practicalHe returned to port, got it safely to a suitable
thickness is around 1/8 inch (3 mm) and anyard, and when I met him first he had started
aluminum hull made from 3/16 inch (5 mm) platework on repairs.
is plenty strong enough for a 35-foot yacht and isThis steel sailboat had cost $75,000, yet the hull
lighter than the steel boat.was riddled with rust which in many places could
If you are building a 40 or 50 foot sailboat, thebe pushed through with a small screwdriver. He
weight saving with aluminum over steel will betold me the rust was mostly along the weld joints
considerable - in all cases this allows the designerand reinforcements.
to put the weight where it is needed for a goodI met him a year later, and he had finished
motion at sea - in the keel. As a result, aluminumwelding up the hull. He had had to replace just
sailboats usually have a sea-kindly motion. With aabout every panel below the water line, and was
racing boat, the reduced weight is an advantage,then fitting the boat out. He had help from his
although a hull made completely from carbon fiberfather and a friend, but he still reckoned it had
will be a bit lighter, but is brittle.cost him $70,000 to repair.