Kobra-anchor

[wagenaar]

I found in two german mail-order catalogues, AWN and Compass, a Kobra-anchor. I have never heard of it and wonder if any forumite has an opinion about this anchor. FWIW. The price of these anchors are lower than for a Delta- or a Bügel-anchor.

 

[hylass]

It's just a chinese copy of the Delta.

Good if you like chinese junk!!...

 

[TonyMS]

I have used one for 2 years now, and reckon it's the first totally satisfactory anchor I've had (after CQR, Fortress, Bruce, Danforth...)

Voile et Voilier did a big review/test of 15Kg anchorsabout 3/4 years ago, and the Kobra came 2nd, after the Spade at no 1.

Who cares where it's made?

Tony

 

[GMac]

[ QUOTE ]

Who cares where it's made?
Tony

[/ QUOTE ]

China - the land that can turn one tonne of raw steel into 2 tonnes of anchors /forums/images/graemlins/grin.gif. Its easy just leave all the dashboards, seats and so in /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

I have actually done this. I measured 1 mt of Italian made 20mm chain which was 8.1 kg. A bit made in china measured exactly the same external dimentions and weighed 7.2kg. Whot The!!!

I care /forums/images/graemlins/smile.gif

 

[wagenaar]

In the meantime I found in the (spanish) Plastimo catalogue, that they also sell the Kobra-anchor and even state " Made by Plastimo". I can not combine this with Hylas's statement: Good if you like chines junk. According to the Plastimo-page, also the german magazine "Yacht" tested the anchor ( in august 2004)and found it the best of the 12 anchors tested. It does not seem to be chinese junk.

 

[GMac]

[ QUOTE ]
In the meantime I found in the (spanish) Plastimo catalogue, that they also sell the Kobra-anchor and even state " Made by Plastimo". I can not combine this with Hylas's statement: Good if you like chines junk. According to the Plastimo-page, also the german magazine "Yacht" tested the anchor ( in august 2004)and found it the best of the 12 anchors tested. It does not seem to be chinese junk.

[/ QUOTE ]

Don't want to be rude but Plastimo also make plow anchors which look very similar to ones built in NZ. Similar is not the best word really, identical is better, even down to the 'made in nz'. I can assure you Plastimo don't make anchors is NZ.

Test, again not wanting to be rude but name an anchor, any anchor, and I'll show you a test where it comes out looking flash.

Tommy Halfinger, Nike and more makes millions of shirts but don't own a sewing machine, go figure.

Can anyone spot the sceptic? /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[wagenaar]

If you compare two chains, as you say to have done, I would first determine to which standard they were made and find out which the tolerances are allowed. There are most certain tolerances on the diameter of the wire used to produce the link. For a 20 mm, hot-rolled wire (actually one should call this a bar), the tolerance is most likely +/- 0,5 mm, which could account for almost 5 % difference in weight. I agree this is not likely to be the case, but 3 or 4 percent is very well feasible. The same is true for the dimensions of the link. I think it gives more insight to compare the weight per link than the weight of x meter of chain. Did the two length of chain which you compared have the same number of links?
In my ( rather extensive) expèrience of steel making, I never have found any remains of dashboards and seats in the steel, nor any influence of these things on the number and size of inclusions. Inclusions have a lower specific weight and should lower the specific weight of the steel. The quality of the scrap does have an influence on the composition of the steel, but usually the trace-elements (copper, nickel, chromium, tin, to name the most important ones) are limited by the appropiate standards. In the end it is not the weight that one is interested in, but the allowed working load and the breaking load. When these are according to the standard, it does not make sense to worry about the weight.

 

[GMac]

G'day again wagenaar.

You are quite right with what you said above apart from one small but very important part.

What 'standards' does China manufacture too?

We have played with some of their DIN766/A standard chain, for example, and it is called DIN but it does not measure as such in the pitch mesurement, has very poor if any calibration maybe 1mm per link on a good bit (DIN766/A standard calls for +2.5/-0.5mm per 11 links on 8 thru 13mm) and we have never tested a bit which meets the standards loads. A few of the winch manufacturers also think the same as they have a 'no warrenty if using chinese chain' policy due to poor if any calibration. It is a metal though /forums/images/graemlins/smile.gif

The Chinese 316 stainless we get for example WILL rust (looks just like surface rust on steel) very quickly where the stuff we get from Italy does not.

Never dropped a genuine Bruce anchor 1200mm onto a concrete floor and seen it shatter like a windscreen, done it to 3 chinese knock-offs though, the rest went back.

By the way the 20mm chain measured damn near identical to the Italian, number of links included.

The bit about dashboards was a tad tounge in cheek but chinese steel just does seem to be lighter for whatever reason. There is a definate quality differance between our chinese and rest of the world stuff though. We have also yet to find a chinese chain that will live up to the standard they say it is, same applies to a lot of other items as well.

The chinese are catching up but still have a long way to go before I'd trust a lot of it.

 

[wagenaar]

Basically the specific weight of solid steel is independent of the specific composition. The only reason I can see for a lower specific weight is the presence of voids. This would fit in with your observation that anchors break in pieces when you just drop them. This is a typical sign of the presence of internal voids. Normally in a metal one finds these voids, gas-inclusions and shrink-holes, in almost every cast object. When such an object is hot rolled the voids close, at least when they have not been in contact with oxygen. In that case an oxyd-layer is formed, which prevents the proper adhesion of the sides of the voids. Your observations indicate a very poor quality control system. The same is true for standards. When one supplies material (or objects) to a standards, it has to comply to all requirements of that standard.
As far as the oxydation of grade 316 goes, one should realise that 316 is simply an indication of the chemical composition. To obtain the non-oxydizing condition the material should be given a specific heat-treatment. How exactly I don't know, but it is important that the material does not show any plastic deformation. If the manufacturing of the final product requires mechanical working, it should be heat-treated afterwards.
Henk.

 

[GMac]

What a mine of information, that's all good.

I suspect you are on the mark with the comment about 'voids'. A compeditor of our sold a pile of chinese chain to a couple of the mooring contractors and inside 12 months boats were drifting all over the place. Usually the 3 year inspection period is fine with other non-chinese chains.

Some of the chain recovered from these moorings looked very 'wasted' and very much like puff pastry, something we have never seen before or since. It looked as if it was made from many 'layers' of steel. You could actually see right thru between some of these layers.

Quite scary really and would easily explain the lower weight.

We do believe that quality control is an area where china needs to do some serious work. It is coming along but still slowly. Imagine how many people won't be working if china gets its act togeather well, something else quite scary.

Nice chatting with you by the way.