|
|
|
|
|||||
|
||||||
From: Bryan Genez (no email)
Date: Sun Aug 15 2004 - 09:39:53 EDT
Len den Besten wrote:
> No one can tell you what the new resins will do in a
> few decades when in molecular contact with water. It's
> a fact that epoxy isn't 100% watertight, nothing is on
> a molecular level. And I didn't find that well known
> yard yet that uses these new resins and gives a 10 or
> more years warranty against osmosis even when I leave
> the boat in the water every winter.
My understanding was that many of the chemicals now used in GRP boatbuilding
are 100 percent watertight. My information, though, is anecdotal. Where
did you get yours?
The current manufacturer of my boat, Valiant Yachts, sells every boat with a
lifetime warranty against osmosis. The warranty is transferable to a new
owner. The only requirement is that the hull be inspected by a surveyor at
least every two years. I know of no other builder who offers such a
warranty. That said, Valiants are not inexpensive; they're certainly out of
reach of most buyers. A new Valiant 42 would cost a minimum of US$350K and
could cost $100K more depending upon the buyer's outfitting requirements.
> Sure, metal boats have their flaws. A steel boat would
> only get on my list when covered with epoxy in- and
> outside when built by a known yard with only minutes
> between blasting and epoxy-spraying.
> Apart from the condensation aluminum is subject to
> galvanic corrosion when you're not careful. I have an
> alarm that indicates a current flowing through the
> hull. I use 9 anodes (!), have to keep the hull 100%
> mass-free and can't just install anyting I like. But I
> must say that it's certainly doable.
I knew of one aluminum owner who required all visitors to empty their
pockets of coins whenever they came aboard. Coins went into plastic
containers that were returned when the visitor departed. He said a copper
coin in the bilge could sink his boat!
> GRP, imho, just isn't the perfect solution as often
> claimed. And, as Robert Gainer tries to point out, we
> all tend to defend our own choices and sometimes in a
> less rational way (what is it with Americans and
> guns?). With all normative judgment stripped I want to
> add to the discussion:
> 1) When you put "speed" in your top-priorities and
> "automatically" choose a GRP boat, carefuly find out
> how wet the hull is. When it's a sandwich construction
> with a wood core, you'll never get it dry again. Often
> the same applies to hulls without a wood core. Be
> aware of the need to haul out every winter. New resins
> still have to prove themselves.
> 2) For serious cruising, consider the impact a metal
> boat can survive compared to a GRP boat
I won't be the defender of GRP here, but will offer two considerations:
1) GRP makes boats more affordable for many people, not just cruisers. The
ability to make multiple copies from a single mold greatly reduces costs.
The biggest disadvantage to metal hulls is that every boat is essentially a
"one-off" and each boat will have its own sailing quirks as a result.
2) I had lengthy conversations with the owner of one of the first Valiant
50s built about ten years ago. While the boat was under construction, he
intended to specify a forward watertight compartment, to protect against
catastrophic flooding. First, though, he had a naval architect run tests
with a model. The tests showed that the boat could hit an immovable object
- such as a ship container - at ten knots and not puncture the hull. That's
impressive (at least to me). I've been on a ship that collided with another
ship at much slower speeds; both ships had substantial fractures in their
steel hulls.
-- Best, Bryan Genez (KB3HMZ) "Capella" Valiant 40 #158 Annapolis, MD ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/A1TolB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/world-cruising/ <*> To unsubscribe from this group, send an email to: <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
|