http://www.ndt.net/article/wcndt2004...bou-khousa.htm

Get hull sonogram when the boat is surveyed. A surveyor who is
knowledgable about steel hulls (and you might consider a commercial/
industrial surveyor, not a yacht surveyor) will know this without
being prompted.


Jere Lull wrote:
Unluckily, I had experience in an industrial setting with this.... He
reported a section of pipe as being full thickness (1/2") about a day
before it blew out. It had to be paper-thin.


Hmmm... now that you mention it, I've known that to happen too. But
that doesn't invalidate the method.... it's technology, not magic!

Make sure the guy can *find* thin metal!

Another PITA was that all paint had to be removed before the reading
could be made.


The instruments I'm familiar with will read thru paint, but the paint
has to be bonded and uniform thickness. You have to have a test
section that is known to be sound & up to spec.

I'm not sure a better method wouldn't be to "sound" the hull with a big
hammer, or maybe a small pickaxe.


Sure. Any place it leaves a dent, you know the hull isn't thick
enough

DSK

ray lunder wrote:
Anyone owned a steel hulled sailboat in the 40 foot range and have
some advice on what to look for when buying one? Thanks as always.

I have owned one steel sailboat, and will never, ever own a steel boat
again.

The rusting just never stops.

Any injury to or failure of the corrosion protection system must be
repaired immediately and perfectly, or the rusting area will expand
rapidly and sooner or later threaten the structural integrity of the
vessel.

Despite your vigilance, some (or more often many) parts of your steel
boat, generally the most difficult areas to inspect and repair, will be
in the process of turning to rust.

My advice is to look instead for a good quality fiberglass sailboat, and
save yourself a great deal of trouble.

Unfortunately your experience provides fuel to these other responders who
actually have no experience with steel boats. I will not dispute your
experience, it happens far too often, but I must ask what effort you
expended to find expertice with steel hull corrosion? There really are
people out there that know how do deal with rust economically and
effectively. If the other casual readers of this thread think that rust is
such an insurmountable issue for steel boats, they should consider the
plagues of other lower density hull construction methods like fiberglass and
wood with fiber osmosis, rot, the lack of ability to host high load
fasteners and the cost or effectiveness of their repair.
Steve


"Moonshadow" wrote in message
...
ray lunder wrote:
Anyone owned a steel hulled sailboat in the 40 foot range and have
some advice on what to look for when buying one? Thanks as always.

I have owned one steel sailboat, and will never, ever own a steel boat
again.

The rusting just never stops.

Any injury to or failure of the corrosion protection system must be
repaired immediately and perfectly, or the rusting area will expand
rapidly and sooner or later threaten the structural integrity of the
vessel.

Despite your vigilance, some (or more often many) parts of your steel
boat, generally the most difficult areas to inspect and repair, will be in
the process of turning to rust.

My advice is to look instead for a good quality fiberglass sailboat, and
save yourself a great deal of trouble.

On Mar 6, 4:01 am, ray lunder wrote:
Anyone owned a steel hulled sailboat in the 40 foot range and have
some advice on what to look for when buying one? Thanks as always.

I own a steel trawler and there is much to be learned in dealing with
metal boats. The boats of today should have been white blasted
immediately followed by multiple coats of epoxy primer before any
finish coatings and all interior areas have at least 2-3 inches of
high density foam sprayed in before building interiors. Exterior rust
is actually less important than interior rust. Many steel vessels rot
from the inside out. Then there's electrical isolation
techniques.....a whole new topic.

Overall, maintenance is somewhat higher (your labor), but not a bad
trade off in terms of vessel strength. If crossing the pond and you
happen to bang into a semi-submerged cargo container, you may get a
dent in the steel. With fiberglass, you're boat is likely to take the
Davey Jones express to the bottom.

Capt. John
http://www.blueseas.com

wrote in message
...
On Mar 6, 4:01 am, ray lunder wrote:
Anyone owned a steel hulled sailboat in the 40 foot range and have
some advice on what to look for when buying one? Thanks as always.

I own a steel trawler and there is much to be learned in dealing with
metal boats. The boats of today should have been white blasted
immediately followed by multiple coats of epoxy primer before any
finish coatings and all interior areas have at least 2-3 inches of
high density foam sprayed in before building interiors. Exterior rust
is actually less important than interior rust. Many steel vessels rot
from the inside out. Then there's electrical isolation
techniques.....a whole new topic.

Overall, maintenance is somewhat higher (your labor), but not a bad
trade off in terms of vessel strength. If crossing the pond and you
happen to bang into a semi-submerged cargo container, you may get a
dent in the steel. With fiberglass, you're boat is likely to take the
Davey Jones express to the bottom.

Capt. John
http://www.blueseas.com

Why not go all the way and zinc spray before the epoxy is put on?

wrote in message
...
On Mar 6, 4:01 am, ray lunder wrote:
Anyone owned a steel hulled sailboat in the 40 foot range and have
some advice on what to look for when buying one? Thanks as always.

I own a steel trawler and there is much to be learned in dealing with
metal boats. The boats of today should have been white blasted
immediately followed by multiple coats of epoxy primer before any
finish coatings and all interior areas have at least 2-3 inches of
high density foam sprayed in before building interiors. Exterior rust
is actually less important than interior rust. Many steel vessels rot
from the inside out. Then there's electrical isolation
techniques.....a whole new topic.

Overall, maintenance is somewhat higher (your labor), but not a bad
trade off in terms of vessel strength. If crossing the pond and you
happen to bang into a semi-submerged cargo container, you may get a
dent in the steel. With fiberglass, you're boat is likely to take the
Davey Jones express to the bottom.

Capt. John
http://www.blueseas.com

Steve Lusardi wrote:
wrote in message
...
On Mar 6, 4:01 am, ray lunder wrote:
Anyone owned a steel hulled sailboat in the 40 foot range and have
some advice on what to look for when buying one? Thanks as always.
I own a steel trawler and there is much to be learned in dealing with
metal boats. The boats of today should have been white blasted
immediately followed by multiple coats of epoxy primer before any
finish coatings and all interior areas have at least 2-3 inches of
high density foam sprayed in before building interiors. Exterior rust
is actually less important than interior rust. Many steel vessels rot
from the inside out. Then there's electrical isolation
techniques.....a whole new topic.

Overall, maintenance is somewhat higher (your labor), but not a bad
trade off in terms of vessel strength. If crossing the pond and you
happen to bang into a semi-submerged cargo container, you may get a
dent in the steel. With fiberglass, you're boat is likely to take the
Davey Jones express to the bottom.

Capt. John
http://www.blueseas.com





Oh no!!!
Not a top poster, not a bottom poster! It's the dreaded NO poster!
Gordon

John,
You are correct about hull strength. The standing rig on my sloop came from
a 70ft aluminum sloop whose owner decided to convert from a masthead rig to
a fractional rig. The name of the boat was the "Dance II" out of Southampton
in the UK. When the new rig was fitted, the owner set out for Gibraltar for
some chartering. At 0200 in the morning running at 8 knots 200 miles off the
coast of Portugal, the vessel struck a partially submerged shipping
container that holed the aluminum hull. The Dance II was lost, but
fortunately without loss of life. Had the hull been made from steel, there
would have been a very good chance the boat would have survived that
collision.

Roger,
Aluminum is good, but corrosion is actually a much bigger problem than with
steel. Even marine grade 5000 series aluminum is very reactive in salt
water, both electrically and chemically. Addionally, it is very difficult to
get a good paint scheme to adhere properly with aluminum. This is especially
true now that Zinc Chromate primer has been banned almost everywhere.
However, the construction techniques available for both steel and aluminum
support watertight bulkheads, where the existence of those are almost
impossible with low density materials and had they been present in Dance II,
the loss of the vessel would have most likely been prevented.
Steve

wrote in message
...
On Mar 6, 4:01 am, ray lunder wrote:
Anyone owned a steel hulled sailboat in the 40 foot range and have
some advice on what to look for when buying one? Thanks as always.

I own a steel trawler and there is much to be learned in dealing with
metal boats. The boats of today should have been white blasted
immediately followed by multiple coats of epoxy primer before any
finish coatings and all interior areas have at least 2-3 inches of
high density foam sprayed in before building interiors. Exterior rust
is actually less important than interior rust. Many steel vessels rot
from the inside out. Then there's electrical isolation
techniques.....a whole new topic.

Overall, maintenance is somewhat higher (your labor), but not a bad
trade off in terms of vessel strength. If crossing the pond and you
happen to bang into a semi-submerged cargo container, you may get a
dent in the steel. With fiberglass, you're boat is likely to take the
Davey Jones express to the bottom.

Capt. John
http://www.blueseas.com

On 2008-03-09 11:21:29 -0400, "Edgar" said:

Why not go all the way and zinc spray before the epoxy is put on?

The experience on the Tanzer list's iron keels has been that POR-15 is
far superior when properly applied. Zinc spray sounds like a great
idea, but it's about the least of the solutions that work -- many
coatings don't.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/