Stainless Anchors and Chain

[Alain d'HYLAS]

Originally Posted by Alan Wheeler

I have searched, but can't find the photo anywhere. I am sure it was someone from here, that has a photo of SST chain that had failed at every single link, due to failure of the weld joint.

Well the following photo is not exactly chain.. but shackle.



this shackle was not used on a mooring line but between a galavanised chain and anchor..

Perhaps this is the only topic where I disagree with the well documented comments of GMac.. but I will NEVER use a stainless steel anchor on my own boat..

[Alan Wheeler]

Anchor I can handle because their is so much metal, having a crack somewhere should not let the entire unit down in a cataclismic break like the chain or shackle. But I would NEVER have aSST chain or Shackels in my anchor system.

[GMac]

Stainless rocks
Not really but it's not as bad as some imagine. There is pile and piles of the stuff out there being used. If it was a big issue more would be said.

One broken shackle (of dubious quality looking at the photo) does not make a problem.

And you forgot the C Links Alain
Just hang on a moment... wasn't someone here making stainless anchors in a recent passed life Hang on again... that might be 2 people here if I remember right

Have a merry Xmas all and continue to boat safe

[swagman]

Originally Posted by GMac

I know what happens to SS, I've seen lots of it. Only ever seen one nasty bit off an anchor chain though. 10mm to 2mm odd in 6 months, mind you it was stored in an carbon fibre locker lying right on the carbon. Did I hear someone say 'Battery'. Chain replaced, locker lined and 4 year later still going fine.

Galvanised chains used on mooring quite often won't last as long as plain old self-colour (black, naked, whatever). The galv starts to fizz as it is designed to do but the tiny current is still there when it runs out and it continues to chomp the steel.

Most crusiers have a budget so most use galv. Makes sense to me.

I was more just wondering if anyone here had any and why did they choose that over galv. Some crusiers do have it or bits of anyway. We are getting asked more and more for it. Seems 'keep the deck clean' is a common reason. Personaly I'm too tight and would only spring for a scrubbing brush :-), if I didn't have such a handy supply :-)

...have cruiser pals who have used stainless chain on their Farr 54 for four years now - done the Atlantic circuit from Sweden with a year in Carib - and now back in Turkey.

They swear by stainless chain cleanliness (not mud being their issue - it's the rust they dislike from previous worn galvanised chain) and remain convinced it is right for them.

And they do anchor a lot!

Cheers
JOHN

There is another issue about using stainless fittings that hasn't been mentioned. Stainless shackles are "rated" for "Working Load Limit" at a much higher percentage of their breaking strength than galvanized ones. They are allowed a smaller safety margin because they are not used for "life-critical" applications like overhead lifting.

Therefore, a "one-ton" WLL stainless shackle is actually a bit WEAKER in the real world than the "3/4 ton" WLL galvanized unit of the same size.

I don't know how stainless steel chain is rated, but be sure to compare breaking strengths and not working load limits which have somewhat arbitrary safety margins built into them that have nothing to do with anchoring.

[GMac]

Originally Posted by GreatKetch

There is another issue about using stainless fittings that hasn't been mentioned. Stainless shackles are "rated" for "Working Load Limit" at a much higher percentage of their breaking strength than galvanized ones. They are allowed a smaller safety margin because they are not used for "life-critical" applications like overhead lifting.

Therefore, a "one-ton" WLL stainless shackle is actually a bit WEAKER in the real world than the "3/4 ton" WLL galvanized unit of the same size.

I don't know how stainless steel chain is rated, but be sure to compare breaking strengths and not working load limits which have somewhat arbitrary safety margins built into them that have nothing to do with anchoring.

Sort of right. WLL's are more a Grade and a regional thing usually. Generally overhead lifting is regarded as 'life-critical' so the margins tend to be bigger.

Some Grades of shackles and chains are rated at differing WLL's. The same Grade maybe rated differantly for differing uses i.e a XX chain rated for (say) anchoring at 4:1 maybe rated at 6:1 when used in an overhead lifting application.

Region wise you have the US G40 (Hightest) which has a lot lower margin than the rest of the world, hence many think it is a lot stronger when there is no differance. There are a few other good example of this but not boat related. Generally the US do tend to use smaller safety margins that the rest of the world. But being smothered by lawyers looking for work they can't be all bad, I'm guessing.

SS V's Galv. Should not make any differance. G40 gear all breaks at the same time (give or take a smidgen) be it made from steel, SS or plastic. The same applies for other grades.

These days you will find most SS shackles tend to be stronger than most Galv. This is talking what is refered to as 'commercial grade' i.e what is available in most chandleries. The loads on most shackles and spookyly low. Generally 'commercial grade' means no proof loading at factory or much in the way of any load testing at all.

There is a nice range of Galv and SS rated gear around. Not often seen in chandleries. Try places that deal in cranes, height safety and trucking type stuff. These tend to use lots of this sort of gear.

Rated gear i.e been tested somewhere anlong the line, tends to be mark quite clearly as such.

Saying all of that the best statement seen for a while is;

be sure to compare breaking strengths and not working load limits which have somewhat arbitrary safety margins built into them that have nothing to do with anchoring.

And just not anchoring. Smart bloke/blokess this GreatKetch

Have a great and safe 2007 all.

[skipperaris]

This is getting more and more interesting.
With the information from this thread I went around the boatyard looking for stainless tackle and saw a pile of stainless chain and an anchor that looks seriously rusty.

Anyone know of a chemical way to clean it?

The story is that it stayed on a muddy bottom for an extended period and this is what the rust is blamed on.

It looks to me like the rust I get on guard rail stanchions the pulpit etc..

[Pblais]

Anyone know of a chemical way to clean it?

When SST has been underwater that long that it rusts you know it is no longer reliable. It's why it was left in a pile. If you look above in this thread you can see why SST chain has it's problems. It does not long term exposure to saly water without air.

As far as cleaning goes what ever you can use on your stantions is what you could use t0o do this job. I would expect you have a large job ahead for lettle in return.

[skipperaris]

Originally Posted by Pblais

As far as cleaning goes what ever you can use on your stantions is what you could use t0o do this job. I would expect you have a large job ahead for lettle in return.

This is not mine. So I'm not going to personally deal with it.
My stanchions and other brightwork I just rub with a dish washing sponge or even a piece of suitable cloth depending on how long I have ignored it.

Not feasible to apply this to all those chain links unless you are imprisoned or cast away on a desert island and have nothing better to keep the mind alive

[skipperaris]

Originally Posted by skipperaris

a pile of stainless chain and an anchor that looks seriously rusty.

Anyone know of a chemical way to clean it?

Yes I know!

As I say the problem was with the grey cells because I knew the way to clean it but it just did not come to me as quickly as I would have liked. I feel very annoyed with myself

The answer is oxalic acid.

I always have it for rust stains but I normally use it for stains on the deck (GRP) so I did not connect immediatelly. In fact I have also used it on stainless and should have known...

And no problem with reliability. This is only a tarnish on the surface.

[Tom Spohn]

I have been to the Ti plant (VSMPO) in Verkhnaya (Lower) Salda in the Ural Region of Russia many times. The plant is sized to equal and even surpass all of the rest of the world's capacity to make titanium. It is very impressive. The Soviets built it to make materials for submarines due the the material's outstanding corrosion resistance. Since the economy was controlled they did not care what it cost and the whole fleet is titanium! Since these are atomic subs they do not last forever and must be melted down. The alloy used (5/2.5) is not easily mixed with other common alloys (6/4 or 3/2.5) so most of the material goes into commercial products like bicycle frames, golf clubs, etc. The shovels are unique in that dirt tends to not stick to the shovel, but they are really more like souvenirs--I have two of them hanging on the wall. VSMPO sells ti to the aerospace and chemical industries in this country and are a good outfit to deal with.

When people ask, "what is titanium made from?", I answer, "electricity". Whether using the Kroll, Hunter, or one of the experimental refining methods, the use of power is prodidgious--which means that the metal is unlikely to drop in price, even though the ore, rutile or ilmenite, is relatively plentiful. Incidentally most of the ti useage in this country is for pigment in white paint since white lead is now illegal.

Titanium, like aluminum is frequently alloyed which increases strength and other mechanical properties a lot. When discussing ti, make sure you know which alloy you are discussing. Pure ti has roughly the corrosion resistance of glass, 2/3 the weight of steel.