On Sat, 16 May 2009 11:03:08 +0200, "Steve Lusardi"
wrote:

Bruce,
Your tests were not valid because you did not reproduce corrosive cases.
Stainless is corrosion resistant only as long as the passive film of oxide
remains on its surface. This passive film can be removed mechanically and
electrically, but in both cases the material will attempt to absorb oxygen
from its environment to recreate the passive film. If the environment is
oxygen depleted, corrosion occurs very rapidly. Here is a case in point,
stainless bolts holding a cast lead ballast plug where water seeps in slowly
surrounding the bolt, but with very slow or negligible flow. As the hull
moves the leads ballast shifts around ever so slightly , but enough to
abrade the passive film. In short order, the surrounding water is depleted
of free oxygen. That is when corrosion starts. It is commonly called crevice
corrosion. Please also appreciate that stainless steel in homogenous, in
that it is an alloy of multiple metals.The corrosion resistance it displays
depends on this homogenous blend. Any disturbance of this blend also
endangers its corrosion resistance, like welding. This fact necessitates
repassivating the disturbed surface in order to restore the original
corrosion resistance. Repassivation is accomplished by removing the
non-homogenous metals from the surface that migrated there during the molten
state while welding. This is accomplished mechanically, electrically or
chemically with acid.
Steve


You didn't read the original post, that I quoted. The original post
stated:

Stainless steel does well in relatively dry environments with access to
oxygen. Look at your home cutlery, for example.
Then go buy a stainless bowl and fill it half full of water.
See how long it takes to develop its first pin hole.
A matter of weeks or less, quite likely.

Which was all I was debating. Not the fact that stainless will
corrode....

Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

On Sat, 16 May 2009 16:38:30 +0700, Bruce in Bangkok
wrote:

Then go buy a stainless bowl and fill it half full of water.
See how long it takes to develop its first pin hole.
A matter of weeks or less, quite likely.

Which was all I was debating. Not the fact that stainless will
corrode....

I had a stainless bowl develop a pinhole in ordinary use.

Casady

On Sun, 17 May 2009 12:20:02 -0500, Richard Casady
wrote:

On Sat, 16 May 2009 16:38:30 +0700, Bruce in Bangkok
wrote:

Then go buy a stainless bowl and fill it half full of water.
See how long it takes to develop its first pin hole.
A matter of weeks or less, quite likely.

Which was all I was debating. Not the fact that stainless will
corrode....

I had a stainless bowl develop a pinhole in ordinary use.

Casady


In a matter of weeks?


Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

"Bruce in Bangkok" wrote in message
...
On Sun, 17 May 2009 12:20:02 -0500, Richard Casady
wrote:

On Sat, 16 May 2009 16:38:30 +0700, Bruce in Bangkok
wrote:

Then go buy a stainless bowl and fill it half full of water.
See how long it takes to develop its first pin hole.
A matter of weeks or less, quite likely.

Which was all I was debating. Not the fact that stainless will
corrode....

I had a stainless bowl develop a pinhole in ordinary use.

Casady


In a matter of weeks?

There is a big difference between 'stainless' steel used for domestic ware
and the type that should be used for boat fittings.
Use a strong magnet and if it attracts the so-called 'stainless' item then
that item has no place on your boat.

On Mon, 18 May 2009 09:39:34 +0200, "Edgar"
wrote:


"Bruce in Bangkok" wrote in message
.. .
On Sun, 17 May 2009 12:20:02 -0500, Richard Casady
wrote:

On Sat, 16 May 2009 16:38:30 +0700, Bruce in Bangkok
wrote:

Then go buy a stainless bowl and fill it half full of water.
See how long it takes to develop its first pin hole.
A matter of weeks or less, quite likely.

Which was all I was debating. Not the fact that stainless will
corrode....

I had a stainless bowl develop a pinhole in ordinary use.

Casady


In a matter of weeks?

There is a big difference between 'stainless' steel used for domestic ware
and the type that should be used for boat fittings.
Use a strong magnet and if it attracts the so-called 'stainless' item then
that item has no place on your boat.


Gee. I got an old stainless year tea kettle. Had it about ten years,
or so and it's been on the boat all that time. And, it has had water
in it for a lot of that time as we live on the boat about half the
time.

Still holding up well, hasn't leaked a drop yet. A magnet sticks to it
too...


Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

Bruce in Bangkok wrote:
...I got an old stainless year tea kettle. Had it about ten years,
or so and it's been on the boat all that time. And, it has had water
in it for a lot of that time as we live on the boat about half the
time.

Still holding up well, hasn't leaked a drop yet. A magnet sticks to it
too...


Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

I have an electric tea kettle of that kind too. Had it for years, no
problem.
And a stainless bowl - that developed a pinhole in weeks when I left it
out with saline in it. Yes, I know - difficult for you to understand or
believe.

Brian W

On Mon, 18 May 2009 06:38:01 -0500, Brian Whatcott
wrote:

Bruce in Bangkok wrote:
...I got an old stainless year tea kettle. Had it about ten years,
or so and it's been on the boat all that time. And, it has had water
in it for a lot of that time as we live on the boat about half the
time.

Still holding up well, hasn't leaked a drop yet. A magnet sticks to it
too...


Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

I have an electric tea kettle of that kind too. Had it for years, no
problem.
And a stainless bowl - that developed a pinhole in weeks when I left it
out with saline in it. Yes, I know - difficult for you to understand or
believe.

Brian W


No, I understand and probably believe. I'm simply responding to some
rather grandiose and illogical statements:

"Put water in a bowl and it will have a hole in it is a couple of
weeks" - I did and it didn't.

"Don't use magnetic stainless on a boat" - I have done and it hasn't
leaked yet..

I notice that you seem to snip the statement I am responding to and
leave only my statement standing all alone.


Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

"Bruce in Bangkok" wrote in message
...
On Mon, 18 May 2009 09:39:34 +0200, "Edgar"
wrote:


"Bruce in Bangkok" wrote in message
. ..
On Sun, 17 May 2009 12:20:02 -0500, Richard Casady
wrote:

On Sat, 16 May 2009 16:38:30 +0700, Bruce in Bangkok
wrote:

Then go buy a stainless bowl and fill it half full of water.
See how long it takes to develop its first pin hole.
A matter of weeks or less, quite likely.

Which was all I was debating. Not the fact that stainless will
corrode....

I had a stainless bowl develop a pinhole in ordinary use.

Casady


In a matter of weeks?

There is a big difference between 'stainless' steel used for domestic ware
and the type that should be used for boat fittings.
Use a strong magnet and if it attracts the so-called 'stainless' item then
that item has no place on your boat.


Gee. I got an old stainless year tea kettle. Had it about ten years,
or so and it's been on the boat all that time. And, it has had water
in it for a lot of that time as we live on the boat about half the
time.

Still holding up well, hasn't leaked a drop yet. A magnet sticks to it
too...

OK, no problem. I have a kettle on board just like that.
I should have made it clear I was talking about boat fittings