Aluminium Hulls, advantages and disadvantages
Alan Davies
from Aluminium. I would like to hear the experiences of others with
Aluminium hulls. I would also like to start a discussion about the
advantages and disadvantages of Aluminium hulls. I am particularly
concerned about electrolysis and the methods of combating it.
Alan Davies
Joe Vrana
says...
Alan, I am not totally famailiar with the electrolisys aspect of
aluminum boats, but I know a few people that have developed leaks in
their hulls. This occurred after a couple of long days of some hard and
heavy boating on Lake Ontario. What happened was the rivets started to
loosen off from the constant "flexing" of the hull. The leaks were small
but it was annoying because the boat in only 2 years old. I wonder if
anyone else out there has experienced a similar situation.
Please let me know how you make out with any further replies.
Joe Vrana
Belleville, Ont. CANADA
Don Welch
>In article <462vmj$e45$1...@perth.DIALix.oz.au>, al...@perth.DIALix.oz.au
>says...
>>
>>I am considering buying a yacht in the 40 to 47 ft range which is built
>>from Aluminium. I would like to hear the experiences of others with
>>Aluminium hulls. I would also like to start a discussion about the
>>advantages and disadvantages of Aluminium hulls. I am particularly
>>concerned about electrolysis and the methods of combating it.
>>Alan Davies
(snip)
What happened was the rivets started to
>loosen off from the constant "flexing" of the hull. The leaks were small
>but it was annoying because the boat in only 2 years old.
> Joe Vrana
> Belleville, Ont. CANADA
I think we should define what TYPE of aluminum hull we are talking about.
Riveted, I agree, is a problem in boats subjected to pounding waters.
WELDED hulls are another story. Here in Oregon we have scads of builders
that turn out some outstanding, nearly bullet-proof hulls that are run in
shallow water, up massive rapids, as well as off-shore. I have been in boats
that hit boulders in the rapids, pounded for hours in the surf and swells of
the Pacific, and never showed any sign of having done any more than sit on
a trailer. Ok, the boulder strike left a shiny streak on the bottom, and
a small nick in the plating, but no other damage. I have to beleive that
any large yacht would be of the welded type. This being the case, I would have
no worries about purchasing it, as long as the quality of the craftmanship
was not in question. Electrolysis has never been a problem with any of the
hulls I have seen. Just ensure that Marine Alloy Aluminum is used, and
sufficient "zinks". Don
John Blaiklock
about 20 extraverts were bulit by linkleters, north shields, uk in the early
80's, intended for racing, four birth, lifting keel, 23'. they are mostly still
all in the north of england, and are raced at blyth, on the north sea. from
my still limited experience, this is what i have found out about small aluminum
boats:
the advantages
they feel very stong, especially overall rigidity.
they have a light structure. most if the mass is where it's needed, in the
cast iron keel.
there are no structural bulkheads inside, more possibilities for variations in
layout. all the strength is in the tubular and box section frame.
apart from antifouling, the hull is completely unpainted and maintenance free.
osmosis is other people's problem.
the disadvantages
they are *very* noisy inside. the slightest slop of water or tap of a rope
gets magnified many times. often down below i've though we've hid something big
only to find it was just a fender swinging in the wind.
they are cold and damp inside in poor weather. it's mainly unlined, and
condensation is a pain.
unpainted aluminum tarnishes to a dull grey, not the prettiest of colours.
getting paint to stick on aluminum is not easy.
galvanic corrosion is not a problem if a few precautions are taken:
1) use zinc for protection in salt water
2) avoid different metals touching whenever possible by using insulating tape
and rubber washers generously
3) copper and lead are the big aluminum killers. ideally make them copper free
boats, no copper, brass or bronze fittings anywhere. a copper based coin in
the bilges undetected can cause havoc. no uninsulated copper gas pipes, and
pick up all the bits when doing wiring.
insurance companies seem to be happy with aluminum boats made by reputable
builders, even when they are old. must say something about them.
hope that info helps
johnb
Rich West
>I am considering buying a yacht in the 40 to 47 ft range which is built
>from Aluminium. I would like to hear the experiences of others with
>Aluminium hulls. I would also like to start a discussion about the
>advantages and disadvantages of Aluminium hulls. I am particularly
>concerned about electrolysis and the methods of combating it.
>Alan Davies
Yea, saw your post the first time, and in two groups!
Rich West
>snip
>Disadvantage: the lighter weight doesn't handle rough seas as
>well...you're sort of like a cork being bounced around.
>snip
This is a function of hull shape and weight. The weight of a hull
alone does not determine the characteristics at sea.
Rich