Spade anchors

[Neeves]

Galvanising can protect adjacent areas so losing a little bit of coating on e.g. the tip of the anchor might not be as bad as you'd think.

This is the theory but it may depend on the quality of the galvanising. Personally when the steel starts to corrode - you are at the top of a very slippery slope. The toe loses gal quite quickly, but the underlying steel still has.layer of zinc rich steel alloy (from the galvanising) and this is kept clean, so you don't notice any corrosion, if you are using the anchor frequently.

Jonathan

 

[noelex]

Spade aluminium anchors are also are prone to the shank bending. I have bent 2 since 2004. On the Spade, if the shank is not 100% straight, they do not work at all well, now using a steel spade for the last 4 years not much rust yet!

Spade warns that the aluminium version is not suitable as a primary anchor.

While not a bad performing model, it is substantially inferior to the steel version, especially in difficult to set substrates.

 

[john_q]

How much time do you spend at anchor. Mine has been buried in the sea bed pretty well for the last 5 weeks. We will be spending the next 18 month at anchor when not sailing

We have been cruising since 2004, mostly at anchor with an occasional Hurricane season marina

 

[geem]

We have been cruising since 2004, mostly at anchor with an occasional Hurricane season marina

I was trying to establish how much anchoring you current steel Spade has done. Mine was rusty within 12 months, but that was as a fulltime liveaboard at anchor

 

[SaltyMetals]

I have been in contact with the production guys in Spade to try and figure out what the problem is. We know that eventually all anchors will go rusty but what started this thread is the impression that Spade anchors go unbelievably rusty very quickly. Yes 80 microns galv thickness would be expected but while i dont think anyone has done the research i get the impression that many anchors actually have about 100 microns. Maybe Steve Goodwin of "Panope" has checked the galv thickness on different anchors. I suspect that Spade is being lead astray by their chosen galvaniser who is using the 0.15% Ni addition trick to reduce the thickness and therefore the cost of Zn consumption. After all, a freshly galvanised anchor is always going to look bright and shiny, whatever the thickness.
I will revert on this thread once i get more info,

I note an earlier comment that Spade is now adding a protective layer of epoxy over the lead face inside the shoe. That was not my impression when i bought a new Spade in 2017-2018. The lead was still exposed inside. I would have thought it should be easy enough for the galvaniser to pour a small amount of molten Zn into that space, on top of the lead.
Andrew

 

[geem]

I have been in contact with the production guys in Spade to try and figure out what the problem is. We know that eventually all anchors will go rusty but what started this thread is the impression that Spade anchors go unbelievably rusty very quickly. Yes 80 microns galv thickness would be expected but while i dont think anyone has done the research i get the impression that many anchors actually have about 100 microns. Maybe Steve Goodwin of "Panope" has checked the galv thickness on different anchors. I suspect that Spade is being lead astray by their chosen galvaniser who is using the 0.15% Ni addition trick to reduce the thickness and therefore the cost of Zn consumption. After all, a freshly galvanised anchor is always going to look bright and shiny, whatever the thickness.
I will revert on this thread once i get more info,

I note an earlier comment that Spade is now adding a protective layer of epoxy over the lead face inside the shoe. That was not my impression when i bought a new Spade in 2017-2018. The lead was still exposed inside. I would have thought it should be easy enough for the galvaniser to pour a small amount of molten Zn into that space, on top of the lead.
Andrew

Mine came with epoxy in 2020 after I mentioned that the exposed lead may be contributing to the failure of the galvanising.
It made no difference. It was still rusty with 12 months

 

[SaltyMetals]

Geem,

It would be useful if someone has the email addr of Steve Goodwin ("Panope") bec i would love to know if he ever made a check of the galv thickness on any of the anchors he has tested. I suspect that the Spade prblm is a low galv thickness since the rust seems pretty general rather than just around the SS bolt or the Pb insert. Sure the sharp edges and the point will always go rusty on almost any anchor but while the design is great th rusting of Spades is a pity.
Andrew

 

[Neeves]

Geem,

It would be useful if someone has the email addr of Steve Goodwin ("Panope") bec i would love to know if he ever made a check of the galv thickness on any of the anchors he has tested. I suspect that the Spade prblm is a low galv thickness since the rust seems pretty general rather than just around the SS bolt or the Pb insert. Sure the sharp edges and the point will always go rusty on almost any anchor but while the design is great th rusting of Spades is a pity.
Andrew

Steve Godwin never reacted too well to suggestions made with a positive motivation.

If he had measured gal thickness, which is easy to do (coating thickness meter) he would have reported it. He did comment on galvanising but there is not much validity without a measure of thickness - as gal life is directional proportional to thickness and hardness (everything else being equal ).

70 microns is a typical thickness for most galvanising - but finding a galvanised marine product, anchor, chain, shackle with gal thickness included, for the buyer, as part of a test procedure - like hen's teeth. Steve Godwin did not quote gal thickness but then anchor chain is never sold with any indication of gal thickness either. The punters who pay for anchors and chain have never clamoured to have the data (no wonder people think its a pastime for the idle rich). The very characteristic, gal quality/thickness, that determines the life of chain is not specified).

But galvanising is an alloying process and alloying is not instantaneous, it takes a finite amount of time to convert Fe to FeZn (and there are 3 distinct alloys and layers). You could potentially have one item given a reasonable soak in the zinc kettle developing hard alloy layers and then spun compared with a similar coating thickness of almost pure soft zinc. The hard alloys will last longer.

A galvaniser on the African side of the Mediterranean will have a customer base for whom he will tweak his process to suit the applications and environment (eg low humidity etc) . Spade anchors might be small part of his business and he is unlikely to alter his practise to suit (he may not even be aware that his galvanising is the subject of complaint).

Interestingly despite the poor reputation for galvanising ...... Spade survives. It must be a winning commercial venture as an anchor sold 30 years ago is almost indistinguishable to one sold today. Many other anchor makers are on their 3rd generation of design over the same time period, many others have come and (almost unnoticed) gone.

Jonathan

 

[vyv_cox]

I note an earlier comment that Spade is now adding a protective layer of epoxy over the lead face inside the shoe. That was not my impression when i bought a new Spade in 2017-2018. The lead was still exposed inside. I would have thought it should be easy enough for the galvaniser to pour a small amount of molten Zn into that space, on top of the lead.
Andrew

Spade used an epoxy layer above the lead on their aluminium anchors to overcome galvanic corrosion problems. I first heard of this in about 2014. Maybe it came later on steel anchors?

 

[Neeves]

I note an earlier comment that Spade is now adding a protective layer of epoxy over the lead face inside the shoe. That was not my impression when i bought a new Spade in 2017-2018. The lead was still exposed inside. I would have thought it should be easy enough for the galvaniser to pour a small amount of molten Zn into that space, on top of the lead.
Andrew

This assumes the anchors are made in adjacent premises. Galvanisers have no reason to pour molten zinc onto anything.

The anchors are galvanised and then molten lead is poured into the toe. Pouring molten lead is not the sort of thing a galvaniser would do, but is the sort of thing a metal fabricator, who makes anchors, might do. So the fluke is made in a workshop and sent to a galvaniser. the galvaniser would normally send the fluke back to the fabricator to have the lead added, adding resin on top of the lead is far simpler than melting zinc and pouring it onto the lead (or taking the molten zinc from a galvanisers kettle).

A number of us have removed lead from a Spade, had it galvanised, lead added back - and adding the lead is relatively easy - you just need a frame to hold the fluke, add lead pieces (pre weighed) and melt with a blow torch. Again those of us who have done this have also sealed the lead with resin.

Pouring in molten zinc from a galvaniser sends shivers down my back.

Jonathan

 

[NormanS]

In the unlikely event of someone trying to pour molten zinc onto lead, I'm not at all sure what would happen. In order to be molten, the zinc would have to be at a temperature considerably higher than the melting point of lead. It all sounds a bit far fetched anyway.

 

[vyv_cox]

In the unlikely event of someone trying to pour molten zinc onto lead, I'm not at all sure what would happen. In order to be molten, the zinc would have to be at a temperature considerably higher than the melting point of lead. It all sounds a bit far fetched anyway.

On one occasion when I was at BE Wedge galvanisers I was shown an anchor that had lead ballast, sent in for regalvanising. Wedge were unaware of the presence of the lead and put it through the galvanising process. Once it entered the zinc bath it exploded, causing some damage to the plant.

When I saw it there was no lead in the pocket at the shank tip. I am not sure whether the explosion was due to the lead only, or whether there might have been water in the void between lead and steel.

There is no reaction between molten lead and zinc. I worked in a factory where sheet steel was galvanised. The zinc floated on lead, which pre-heated the steel before applying the zinc.