[paul.fr]

What makes stainless steel stainless? Would you class rust as a stain? i would. Well, i have this bathroom mirror and it has rust on it, how did that get there?

[JimBob]

There was a heard of oxymorons running through your bathroom. Their horns nicking the fixtures and their mouths were drooling. Obviously, one of the critters nicked the mirror and another drooled on it at the same point.

But I do not consider this a stain, it is corrosion. A stain - and possibly a divorce - would be to spill red wine on your wife's new white couch.

Actually, stainless steel has a fair amount of chromium in it to prevent rusting. The product is commonly know as "stainless steel" but is marketed as "corrosion resistant" steel. It will eventually rust over time.

[paul.fr]

There was a heard of oxymorons running through your bathroom.

I am clearly confused by your answer, but i must say No. just one moron, bored whilst shaving.

[DoctorBeaver]

There was a heard of oxymorons running through your bathroom.

I am clearly confused by your answer, but i must say No. just one moron, bored whilst shaving.

Oh yes... morons insist on being clean-shaven. And they always dress in suits.

[JimBob]

But the bit at the end is real.

"Actually, stainless steel has a fair amount of chromium in it to prevent rusting. The product is commonly know as "stainless steel" but is marketed as "corrosion resistant" steel. It will eventually rust over time."

( to himself - lousy morons on this site don't even read the whole answer, just the first bit, make an assumption there is no viable content and start acting silly like the twits of the year on MP. my goodness, can I ever combine humor and fact and get the facts recognized. It is lame, totally lame! never seen the like - bunch of pub crawlers trying to act smart grumble, snort, gets disgusted kicks the dog, throws a vase at the cat, wipse the spittle off his ......... )

   

[paul.fr]

My dearest JimBob, sage who knows his onions.

I did realise that "the bit at the end" was real. I have added it to memory. i did not want to embarrass you by the praise and wonder i felt reading your answer, so i thought i would give a jokey reply.

yours in awe, Paul

[lyner]

There are several grades of 'stainless' steel. The cheaper ones are magnetic and the expensive 'marine grade' are not magnetic. It's not a complete 'acid test' but you are less likely to be ripped off in a ship's chandlers if you take a magnet with you .

[JimBob]

True, SophieC, but if I remember correctly even the ships have cathodic protection to keep the steel from rusting. I do know that off-shore rigs have cathodic protection on everything, especially production platforms with the ship grade steel valving and the plumbing connecting these. 

cathodic protection - see http://en.wikipedia.org/wiki/Cathodic_protection it even says ships were the first to have it - cathodic protection that is, not morons, although that could also be a fact as well.

[lyner]

Ships aren't made of stainless steel - much too expensive and a pig to work with.. It's usually  mild steel and needs plenty of electrolytic help.
Sacrificial anodes of zinc or  magnesium are used. I'm told that domestic aluminiumware  is not good enough (local action in the alloy itself reduces the protection of the boat). That's a shame 'cos it could save a lot of money on high-cost anodes, fitted to yachts etc. I always fancied trailing an old saucepan   behind my boat .
Unless someone knows better ? . . .

[another_someone]

Well, if you don't want corroding boats, why use steel when so many other materials exist (from wood, to GRP, GRC, steel reinforced concrete, and I'm sure a few others I have not thought of)?

[Bored chemist]

Steel is cheap and relatively forgiving of poor design. It bends before it breaks so at least you get to know about the problem. (I know there havebeen exceptions to this.
Oh, and did I mention that it's cheap.
Plenty of boats are made of wood or GRP too but they are not economical compareed to the steel ones.