[PUP] Let's design the perfect passagemaker - Lets start ....

[pmouligne at aol.com]

Steel or aluminum "tougher than fiberglass"........Please....

Composite hulls can be made as strong, as stiff, as impact resistant as any other materials and still be lighter than equivalent design in steel, aluminum or wood...It is strictly a matter of proper engineering and design.
?At equal weight per sqft of hull or deck (of course, taking into account the weight of frames needed) a composite laminate, which might include a core material, will outperform any physical?`properties of other building materials.
I am sorry but?other opinions?are not based on engineering or proper knowledge but just on a "old wives tale" ...
But it is OK, of course,?to "like" other materials than composites...And all materials can make excellent boats...

?As far as outlasting wood, steel or aluminum it is also a matter of engineering and maintenance. But composite will require much less maintenance than competitive materials to last as long...

Patrick Mouligne N4601


-----Original Message-----
From: Ken Williams <kenw at talkspot.com>
To: 'Passagemaking Under Power List' <passagemaking-under-power at lists.samurai.com>
Sent: Thu, 30 Oct 2008 4:15 pm
Subject: Re: [PUP] Let's design the perfect passagemaker - Lets start ....



Hannu Venermo raised the question of doing a steel hulled boat. 

The hull seems a good starting point for a discussion... 

To my knowledge there are only four options for the hull: wood, fiberglass,
aluminum and steel.

I know nothing about the pros and cons of a wood-hulled boat, so I can't
comment on them. My perception is that wood is great, but not practical, for
cost and maintenance reasons.

As to fiberglass:

Pros
----

- Inexpensive to manufacture in a production environment
- Produces a good looking boat
- Can be painted
- Easier to insulate than steel or aluminum

Cons
----

- Less collision proof than steel or aluminum
- Longevity uncertain
- Expensive in small production runs (one-offs)
- Tough to do major repairs (if significant damage)

As to Steel or Aluminum:

Pros
----

- Tougher than fiberglass
- Integral tanks are possible (double-hull with tanks in middle)
    + Usually provides for huge fuel capacity
- Easy to fix anywhere in the world (just weld on a patch)
- Possible to manufacture in limited quantities

Cons
----

- Electrolysis. Any two differing metals, that touch, are going to cause
problems. 
- Rust
- Sweating
- Can be a permanent maintenance nightmare. Need to inspect constantly
- Can't be painted 
- Resale of metal boats is not good. Too many buyers fear them (right or
wrongly - but certainly)
- More expensive than fiberglass in mass production(?)
- Top heavy, if all steel is used .. and, a tricky problem if a
steel/aluminum combination is used

Ken Williams
www.kensblog.com
Sans Souci, Nordhavn 68
_______________________________________________
http://lists.samurai.com/mailman/listinfo/passagemaking-under-power

To unsubscribe send email to
passagemaking-under-power-request at lists.samurai.com with the word
UNSUBSCRIBE and nothing else in the subject or body of the message.

Passagemaking Under Power and PUP are trademarks of Water World Productions, 
formerly known as Trawler World Productions.