A question for the chain guru

[John B 119]

Knots , since you so kindly pointed out that my chain could do with a re galv I've been planning to do that . Did I also read somewhere that a chain should only be regalvanised once ?

This is a full chain setup.. the links have something printed on them ... like P W C ? P something something( early onset of alzheimers setting in here)

[Guest]

You called?

 

I think you'll find that stamp is 'PWB' or better still 'PWB-L'. Pitt Widdal Bennet it was called back in the day, now PWB Anchor. Owned by some multinational and mostly made in Melbourne and some in china. The 'PWB-L' is Aussie made and good stuff, I'd use it myself happily.

 

PWB and Maggi are about the 2 only non made in china short link anchoring chains available in NZ, contrary to what many shops will 'spin' you basically due to lack of knowledge and effort to find out. Maggi is usually cheaper and stronger but either is good. Sometimes you'll find some Serafini drifting around which is made in Brissy, another good chain.

 

Re-galvanising? As long as the galvaniser isn't a bunny you can happily regalv your chain once or twice without too much stress. You can regavanise it more but the experts will strongly suggest you get it tested afterwards. Each time you galvanise you do drop the strength a little, or a lot of you go to 'Cheap as but no real idea what we are doing Galvanisers Ltd'.

 

We would recommend taking it to East Tamaki Galvanisers if in the Akl region. The boss dude Bob is a long time yachtie and knows his game very very well. If your chain is rooted he'll tell you and you can trust his word. They are also have a spinner so you don't end up with a steel link reinforced lump of Zinc as we have seen come out of one or 2 other places. We have no connection to ETG but just know they are on top of their game in regards to chains, and most other stuff I'd guess.

 

If your chain has got to the 'flaky rust' stage no good galvaniser should regalv it for you. If someone says 'Yes no worries' be worried, they should know better. Obviously if it was your OLD anchor chain being turned into fence, one of them drag around your farm to flatten the ground dodackies or something non critical, that is a different story.

 

If someone says 'Oh don't worry I've regalved mine 6 times so far and it's all good', DO NOT anchor down wind of them. They could very easily have very very weak or brittle chain likely to bust at any time without warning. Most good chains will show signs if going bad before it goes critical, assuming you take the time to look at your gear now and again.

 

I did find this handy info on re-galvanising chains which could be worth a read. It goes into it all a bit deeper.

 

http://www.chainsropesandanchors.co.nz/advice/regalvanise

 

A Guru? I think knot. More just one of the dieing breed who thinks they should actually know a few things about the products they deal with rather than make up some sale pitch on the fly to suit what you asked them for. It's a shame more don't think the same.

[PaulR 3]

I looked at the costs of regalvanising about 18months ago at another location, knot the East Tamaki KM referred to.

 

There is a minimum fee and so it it may be smarter for 2 or 3 people go for a joint one invoice deal.

 

It was more for a crusty CQR anchor that I was thinking mainly about, but then any lead in the point will be lost and you will need to get the lead put pack in afterwards.

[Guest]

And if you regalv a leaded anchor make sure the lead goes back in either by them or yourself. If you don't know how much to put back in work on the 'more is merrier' theory and fill the bastard right up.

 

Just watch some don't fill it with zinc though. The decrease in weight can affect performance with some.

 

Good point there Paul.

 

The min cost probably wouldn't come into play with a length of anchor chain.

 

As a ball park only work on $2.75-3 per kg to regalvanise something. More if it need blasting or any pre-treatment.

 

So if you have 8mm chain that's about $4.20 per mt working on $3 per kg.

10mm around 6.50 per mt

12mm around 10.50 per mt

 

So again as a ball park, regalvanising is around 50% the cost of new good chain or 75% of new but shitty chain.

[Murky 3]

I think you'll find that stamp is 'PWB' or better still 'PWB-L'. Pitt Widdal Bennet it was called back in the day, now PWB Anchor. Owned by some multinational and mostly made in Melbourne and some in china. The 'PWB-L' is Aussie made and good stuff, I'd use it myself happily.

Disappointing. In your heyday, you would have come through with the suburb of Melbourne, which exact line in the factory it was manufactured on, and the machine operator's name (no, it is no good saying now that his name was Dazza) and the relative humidity on the day.

 

You really are distracted by this multi-hull mid-life crisis, aren't you? Poor little mite.

[Guest]

Bundoora is the suburb in Melly if you want to pop in for a visit, which is actually a lot more interesting than many would think. Chain making isn't quite as simple as just bending a bit of wire.

 

Which line and operator depends on Johns chains vintage and as good as I maybe, my skills don't allow chain ageing via the interweb that often. But I'm guessing line 1 and it was Steveo, Dicko, Brucie or maybe Shelia

 

Multi and with 2 motors.... you may have a point

 

As a FYI - some galvanisers do send the chain to ETG to be done rather than do it themselves. Go direct would be my call and you can chat yachts with Bob.

[John B 119]

Thanks for that Knots.. . The chain is in good nick and has just become 'rusty' or really only just started to shed a stain in this last season so I'm at the poifect point to refurbish it.

My feeling is that it hasn't been regalvanised before because it has no evidence of extra coatings or dags ( as I've seen on regalvanised stuff before.).

[Guest]

If a PWB chain has been regalved previously the stamping wouldn't be sharp and crisp, if that makes sense. The stamps are quite shallow so a extra coat of galv does tend to fill them up a bit.

 

Daggy bits aren't exclusive to regalved chain and some galvanisers are that good they might knot leave any behind so it's a little tricky to spot sometimes. But your right talking 'in general', often there are traces of regalving.

 

And while on daggy bits. With the 2 types of galvanising being used today (NZ only tends to run one as far as I know) people are starting to confuse old school galving with newbie galving. Done well both are good so no dramas there.

 

Assuming the daggy bits don't interfere with the chain when running in the winch, the winch usually wins anyway by knocking badly placed daggy bits off fast, wouldn't you think the more galvanising the better? It is a 'sacrificial' coating after all, the more you have the more sacrificing there has to be before you get to bare steel and rust. Hello people, isn't that what you are paying extra to have galvanised chain for?

 

That applies a lot more to old school galv (the shiny silver coloured, as used in NZ) as opposed to the lot thinner newbie galv (a matt grey look, ex the EU and the US usually)

 

The difference is the old school galv has aluminium in it as a bit of a baulking agent so to speak along with it's almost zinc like, if knot a bit faster, sacrificial properties. Newer galv has had the alloy removed so is more pure zinc and knot as shiny. The new galv does appear to 'self-heal' better than the old. While it can look quite thin it does stand up better than most would expect. The stress when the 1st lots started appearing 7-8 years ago was large, we have none or no more than old galv now.

 

And of course we have some, knot all, 'hot dip galvanising' which is actually just a zinc/nickel type plating that's been 'washed' to give it a hot dip look. It's knot good and can be hard to spot. Most often found in hardware shops being sold out of small plastic buckets at a price they should be supplying tampons with to soak up the blood that would bleed from your arse when at the check out. Luckily that finish does seem to be seen decreasingly of late, that's good.

 

We did a suss to see if we could find out why they removed the alloy from galvanising. It happened 1st in the US quite a few years ago now. The best we could come up with is some study found the fish were getting Alziehmers due to alloy in galvanising so a bureaucracy somewhere said 'No more alloy'. And that's spread worldwide now, in the bureaucracy feeding bureaucracy way it seems to happen these days. That explanation is bloody stupid but that bloody stupid, it just maybe true

 

Haven't done anything technical this week so your getting some now to ease the pressure

[wheels 544]

a damn complex and long winded subject about Metals and heat and coatings, so i am going to try and keep this basic a short...'ish.

 

Hydrogen embrittlement is the easiest to tackle, so i will start with that.

Firstly, the chemistry of metals is increadibly complex. They are made of Crystals and those crystals grow in all kinds of ways and create a grain structure.

When metal is heated, strange things happen with those grains and Crystals. But mainly, they start to seperate and we see that as metal expanding as it is heated. Hydrogen molecules can seep down into those Crystal structures and as the meatl cools, the Hydrogen is trapped. Think of it as Osmoses Blisters on a GRP hull. As the metal cools, the crystal structure come close together again, and the Hydrogen Molecule acts as a wedge. Eventually the pressure is so immense the crystals are cracked apart and the Crack starts to follow the Grain. In the case of Galvanising, the Metals are dipped in Acid. Normally sulphuric and the Acid is normally Boiling. Acid is rich in Hydrogen Atoms.

 

Liquid metal embrittlement is another issue. Not much is known about this. Which in our modern space age days is quite amasing. But metal in a liquid form placed in contact with a solid metal, will cause the solid to become Brittle. And Temperature is not waht causes it. For instance, Murcury is not allowed on aircraft. the reason is that Murcury accidentally coming in contact with the Aluminium alloy Aircraft materials will cause embrittlement and rapid and severe strength loss. In the case of our Hot dip Galv, we have a Zinc Alloy in a liquid form that does xactly the same thing.

 

Heat treating of metals is used to make metals do all sorts of things. You can increase tensile strength, make the surface increadibly hard or make the metal very soft and malleable. It is very very complex. But by using different temperatures, times of maintaning a temperature, time in cooling and what it is cooled in, will give a particular result. Different metals react differently. Some will soften while others may harden with the identical process. This is where KM's Galv Guy he tlaked about has a clue over perhaps some other Hot dippers. It is all about how Hot, how long it is kept that hot and how fast it is allowed to cool again, that determins what happens to the metal.

In general Galvanising today, it is not very "specialized". It is all about being "competitive". So the real Guru's are either not about now, or they don't care about the tricks used in the processes. Finding a Galv Guru like KM's is now rare.

Lead is added to the Zinc to create a better "flow" of the Zinc (among other things) and helps to coat the metal quickly. This means the time in the Hot bath of molten metal can be reduced. But more importantly, it means the excess Galv runs freely off the newly coated metal, leaving a lovely smooth finish, or no daggy bits. Low levels or none at all of Lead tends to be what leaves the Galv with the sharp daggy bits hanging off it.

Aluminium was added to Zinc as part of a special process called the "Sendzimir process". It resulted in the Zinc coating bonding with the metal and not just coating it. The process came about because the very early techniques had a problem where the Galv would not adhere well and fall off when worked or flexed. Mostly it is used in thin metal sheet and the Product Zincalum is one of them.

 

Now lastly, and I left this part till last on purpose, how a steel is affected by heat is also determined by how good the quality of the metal was in the first place. And this is the difference between a good quality steel like found in PWB chain and a cheap Chinese. They maybe steel, they may even be the exact same Mix, in fact it is possible, (not likely) but possible to take the same molten metal from a Furnace and by the way it is handled through out the process, you can have two completely different metals at the end. One strong high quality and one very inferior. It is all about what happens to that Grain structure. A good steel will handle the Hot Zinc Galv bath better and more times than the cheap stuff will.

[smithy09 50]

That was brilliant Wheels. ....We are not worthy.....

[Guest]

Get your pick zinc arc sprayed. The same cost in my experience and abrasion resistance is FAR superior. Not sure about the cost effectiveness in NZ for arc spraying chain but it's about the same here. No excessive heat in the process and it LASTS. We had our CQR done in Wellington in 06 and it has seen many rocks, reefs and bommies but the only sign of rust is some bleed around the pivot, which is understandable. I have had experience of this system for over 10 years in commercial workboat applications and unless I was protecting hollow section material (where arcspray won't reach) I would ever use hot dip again.

[wheels 544]

It's a great system Pete. And there are about half a dozen different methods of spraying. From plasma, electric arc and believe it or not, there is also a Cold method now. I don't know how that works. The big plus is you can apply it as thickly as you want and at least the Plasma method, the Glav is applied in a way that makes it bond to the parent metal.

I don't really know here, but the only problem I see with doing chain is that it would be difficult to not weld the links together and it is a "spray" so you would waste a lot of Galv. Thus the cost could be expensive. But certainly a good way to maintain the strenght of the chain.

[Guest]

We have a zinc sprayer just down the road and I had a chat to him about it all. The long and the short of it is that good and cost effective for anchors and the like but when talking chain it is up there to get total coverage. He uses some system that involves big power leads but that's about as techo as I get on that

 

Commercial ships tend to use Alloy rather than zinc Zincs due to the weight. But then ships also measure their 'zincs' in square meters so have a LOT.

 

And the 'zinc' used in the rich rich galvanising and in your boat zincs isn't pure 100% zinc. Some cheap ones are I'm told. Pure zinc zinc aren't that flash. They add some secret herbs and spices to make it work and last better. But it is still in the region of 98% zinc.

 

And a quick bit about chain metal quality. China made verses EU, US or Aussie made, why a price difference?

 

Excluding the fact you can get a LOT bigger margins selling chinese than the others, hence the reason most have no gone that way, what else is involved.

 

There is minimal labour content in making chain so that can be pretty much excluded.

The Chinese and Rest pay the same for the machines, at a guess but one would expect it to be pretty close if knot the same.

So if the machines cost the same and labour content can be excluded how can one make it for 1/2 the price of the other?

 

3 options -

1 being steel quality. Good steel costs a lot more than recycled Toymotors.

Another option, are processes being missed? By that I mean good makers calibrate (extra machinery) and Normalise (de-stress) their chains (another machinery)

Or option 3 is a combination of those 2.

 

From what we have seen, found in testing and sadly many punters have found out in real life, it's option 3.

 

There is one galvaniser in NZ who has told us the cheap chinese chain coming into NZ is going to buy him a new motor home inside 2 years and he loves every bit of it He reckons he's galvanising a lot that it isn't even 18 months old. That bit is spooky but does fit the pattern seen out there.

 

FYI - we also sell chinese made but we won't if it's for a mission critical use, we just respect our punters too much to do that.

[wheels 544]

That was brilliant Wheels

Nah not really. I only scratched the surface. It is so darn complicated. I had to know a certain amount of it for welding. I imagine the guys that do the real specialised welding would know a heck of a lot more about it.

China is now the biggest producer of Steel in the World. Just because the steel is made in China, does not mean it is automatically inferrior to Steel made anywhere else. Chinese Chain and like many things Chinese we see here in NZ, is made cheap to be cheap and the ultimate cost is to us, with the ultimate gain to those guys creaming it to buy their motor homes in a year or two.

There are two process to make Steel today. Basic Oxygen Steel and Electric Arc Furnace Steel. EAF uses 100% recycled Steel. The process is actually the more basic in reality. They simply melt scrap. Because of this, they can never 100% control a mix of what is in it. Although most scrap merchants try and seperate hard steels from Soft and from Cast, there is still a mix and of course other metals like Copper etc end up in there as well. For this reason, the end metal tends to be quite hard and not easily worked. So materials like steel beams etc are made from it, because it is actually rolled while hot into it's final form and will not have it's form changed again.

The BOS process is a lot more technical. Int his process they can actually control what goes in to the mix. They usually start with Iron Ore, with small quantities of scrap. The metal is constantly tested and chemicals and process can actually take specific metals out of the Mix. Then an alloying material is added to make the mix spicific to what is required. Pure Iron is just that. We call it Wrought Iron and it is soft and can be cold moulded and shaped. Then by adding Carbon to the Iron makes basic Steel. Steel is an alloy of Iron adn what ever else is added. The more Carbon, the stronger and harder the steel becomes till you reach 2.1% carbon. Higher amounts of carbon make the Steel Brittle and easily broken and that is our Cast Iron.

By adding othe metals like Vanadium, Titanium, Chromium, Nickel, Molybdenium, Tungsten, Cobalt etc makes the steel into specialised materials, like Tool Steels, Stainless Steels (of which there are dozens of types) Spanners, Sockets, blades and so on. Then on top of that, those alloys are heat treated and surface treated to make them different again. NBow this is the real complex part because i can never remember which is what. But by changing that Crystaline structure as i said earlier, you can then have austentite and martensite Crystal structures which makes the steel different yet again.

Now back to the chain, so lets assume the Metal used is an OK quality. The next issue and the most important area of chain and biggest issue of failure, is the Weld. There are different ways the Links a welded. It can be induction welded, Arc welded and Forge Welded. There maybe even other methods. Links can be bent Rod or can be Drop forged. It all just goes on and on.

[Guest]

Knots , since you so kindly pointed out that my chain could do with a re galv I've been planning to do that . Did I also read somewhere that a chain should only be regalvanised once ?

This is a full chain setup.. the links have something printed on them ... like P W C ? P something something( early onset of alzheimers setting in here)

 

So you ready for the pop quiz now

[col j 0]

i got another question for the chain man.

 

how fast is too fast to drop an anchor? and im thinking how the f**k do they get it back up?

 

[Guest]

Bloody hell, is that normal? Can you imagine what it's like below deck in the chain locker?

[John B 119]

Knots , since you so kindly pointed out that my chain could do with a re galv I've been planning to do that . Did I also read somewhere that a chain should only be regalvanised once ?

This is a full chain setup.. the links have something printed on them ... like P W C ? P something something( early onset of alzheimers setting in here)

 

So you ready for the pop quiz now

 

 

When I get back from the counselling session I just booked.

[Guest]

Now stop being silly Mr Squid, no way is that a Bloody hell, it's a full on Holy sh*t smoke up that baby

 

See the whole boat start shaking when it took off? And don't ya just have to love all that smoke, a magnificent effort indeed.

 

I'm guessing a bit here but I reckon that's around a 65mm studdy. So assuming it is and I counted at least 5 shots (27.5mts a shot or sometimes called a shackle) but it could easily have been more as it was screaming out under the cover of smoke, you just watched around 13,000 kilos being dumped over the bow, quite possibly a pile more.

 

Getting it back? I'd say using many many gallons of diesel driving a big wad of hydraulic action and certianly a lot slower than it was deployed :)

 

Great find Col, I love that and the lads at the oriface tomorrow will need to be hosed down after seeing it.

 

And on a slightly more serious note, see when the chain took off the brake drums smoking up as they tried to slow it's roll? Even though your boat and chain is a little smaller if you let it run away during deployment you to could also f*ck your winch or look like you are trying hard. Always control deployment speed when chucking out a all chain rode as it will easily run away on you and be a right arse to stop.

[Guest]

Knots , since you so kindly pointed out that my chain could do with a re galv I've been planning to do that . Did I also read somewhere that a chain should only be regalvanised once ?

This is a full chain setup.. the links have something printed on them ... like P W C ? P something something( early onset of alzheimers setting in here)

 

So you ready for the pop quiz now

 

 

When I get back from the counselling session I just booked.

 

Sometimes it pays just knot to ask

 

But I must say you generated a seriously fact filled thread pretty fast, nice work