Are aluminium boats a liability?

[Sandy]

If anybody would like to gift me their Boreal 47 because of it fizzing, I'll be round to collect it pronto.

 

[William_H]

I crewed on a >150’ aluminium super yacht. Only 4 years afloat at that stage but no problems. That said, we were very careful indeed about isolating any dissimilar metals, and a diver was down and checking anodes pretty much fortnightly.

Have to admit being more concerned about the likely effects of a lightning strike when sailing through an electrical storm though.
ent straight through. Much older boat though. Swings, roundabouts etc.

Re lightning I would think that an ali boat would be the safest and best in lightning strike. There should be enough ali with low electrical resistance to sea to carry the current easily. Of course the current surge and magnetic field produced could induce voltage in to electrical circuits to demolish electronics. ol'will

 

[Neeves]

At the fish farm where I used to work, we had a small aluminium workboat that was still going strong after 30yrs. And those boats are not in any way pampered! But it was very simple, with just an outboard, nav lights, and a VHF. So I don't think aluminium is inherently unsuitable for seawater use. Trouble presumably arises from stray electrical currents and dissimilar metals corrosion which must get harder and harder to avoid add the boat gets bigger and more complex.

Here 'tinnies' are common place (no tin used - all aluminium ). They are used as little leisure run-about with an OB. They seem to last forever. I suspect there are more locally made fibreglass dinghies but it might be a 60:40 ratio in favour of glass. Once you move up is size where they cannot be carried (the OB contributing to a lot of the weight) there are still a lot of aluminium runabouts, Barcrusher Plate Alloy & Aluminium Fishing Boats, Australia | Bar Crusher. or Quintrex, for example. Move up in size further and Australia has a large industry building significant commercial vessels - in aluminium Crafted With Capral - RDM Constructions | Capral Aluminium. Whatever the problems that might be expressed on this thread - they obviously are not insurmountable - or none of these companies would exist.

It would be interesting, instead of largely condemning aluminium, to look at how Australia manufacturers have over come the issues and wonder why those solutions have not be incorporated to allow major aluminium boat builders to prosper in other locations.

Jonathan

 

[Neeves]

If you dig into this site:

https://www.wrightsons.com.au/

You will find this is yet another boat builder, MoBos, in Australia using aluminium. The complexity of build will be no different to a yacht. The vessels that the Wrights build might not all have sauna's or jacuzzis but they will have the same wiring, the same need to use mixed metals etc etc - and it does not worry the builders nor their customers.

Now why aluminium seems 'everyday' for some but an exotic or liability for others is the crux of the question (that I cannot answer). Some boatbuilders, and owners, take aluminium in their stride others reject it out of hand - sounds too much like choosing an anchor.

And on the subject of anchors

I know this builder as one of the Directors took note of my ideas of a lightweight high tensile anchor chain and I managed the production of his new rode (I think for an Ovni).

Its a compliment, which I enjoy, when someone who has marine experiences well beyond anything I do accepts new ideas - invests their money in those new ideas - and is happy with the results. Makes a change to some of the negativity here.

Jonathan

 

[Bajansailor]

I have a naval architect friend who is very experienced in designing aluminium vessels - he used to work at Austal (mentioned above) in Australia before setting up his own design consultancy.
And he has written / presented numerous papers about aluminium vessel design and construction.
I sent him a link to this thread, and he summarised everything up very nicely in a nutshell with :
"Aluminium is all about the quality of build, and attention to detail - ignore both at your peril!".

And I will add that in essence, one could say exactly the same thing about fibreglass, steel or wood construction as well.

 

[rotrax]

Here 'tinnies' are common place (no tin used - all aluminium ). They are used as little leisure run-about with an OB. They seem to last forever. I suspect there are more locally made fibreglass dinghies but it might be a 60:40 ratio in favour of glass. Once you move up is size where they cannot be carried (the OB contributing to a lot of the weight) there are still a lot of aluminium runabouts, Barcrusher Plate Alloy & Aluminium Fishing Boats, Australia | Bar Crusher. or Quintrex, for example. Move up in size further and Australia has a large industry building significant commercial vessels - in aluminium Crafted With Capral - RDM Constructions | Capral Aluminium. Whatever the problems that might be expressed on this thread - they obviously are not insurmountable - or none of these companies would exist.

It would be interesting, instead of largely condemning aluminium, to look at how Australia manufacturers have over come the issues and wonder why those solutions have not be incorporated to allow major aluminium boat builders to prosper in other locations.

Jonathan

Here in NZ the popular sports fishing boat industry is about 60/40 aluminium to GRP.

They are worth googling. Very seaworthy, fast and as I see plenty of old ones about, durable.

A couple of makes of aluminium pontoon boats too - not the lake types the Americans have, but serious seaboats.

The Kiwi's and the Finns are fighting about who has the most boat ownership per capita of population in the world, so NZ boat ownership is high.

A friend has a Kiwi Kraft with a big Yamaha O/B. It is bloody quick!

 

[Neeves]

I have a naval architect friend who is very experienced in designing aluminium vessels - he used to work at Austal (mentioned above) in Australia before setting up his own design consultancy.
And he has written / presented numerous papers about aluminium vessel design and construction.
I sent him a link to this thread, and he summarised everything up very nicely in a nutshell with :
"Aluminium is all about the quality of build, and attention to detail - ignore both at your peril!".

Building boats, yachts, (Ben, Jen, Bav, Lagoon, FP) that are capable of crossing oceans is all about the quality of build and attention to detail - ignore both at our peril.

Either modern yacht builders have the skills, or the boats they currently build are a liability - I am accepting that aluminium is not quite as easy build volume as with glass and resin - so I'm not comparing apples with apples.

My take is that if you can build yachts that can safely cross oceans then you have the 'management' skills to build aluminium vessels.

I'd also say - aluminium yachts have a terrible reputation (they fizz), whether this is deserved (it is not a deterrent in parallel markets - MoBos, see above and earlier posts, Austal Ships)) - but we are a reactionary lot, don't let me mention lightweight anchors or catenary ). It would take a major change in attitudes to drag aluminium yachts (or lightweight anchors and light chain) into mainstream.

New Developments In Aluminum Shipbuilding

Jonathan

 

[Neeves]

May be aluminium wins for one off designs?
One off in GRP for Carbon Fibre reinforced plastic is more difficult to build and probably more expensive in both labour and material cost.

Most racing yachts, large ones, are one off designs.

Jonathan

 

[Kukri]

Returning to sailing

Pacha seems to prove that it is quite possible to build long lasting, beautiful and performance yachts.....

from aluminium

The hull its metal, not plastic

Pacha Sailing

Jonathan

PS, her anodes are the size of generous dinner plates.

A fellow member of the Nic 55 “not do much an owners association, more a whatsapp group”.
She displaces around 17 tons whilst her GRP sisters come in around 23 tons. Which is interesting in itself.

She is ashore in Portugal for the winter, looking fabulous, and might be tempted into the Channel presently.

Going further back into the mists of time, back to 1949 in fact, the fabulous Laurent Giles reverse sheer Class 1 offshore racer “Gulvain” is ashore at SYH. I think she may be the original aluminium alloy yacht?

 

[Neeves]

She is ashore in Portugal for the winter, looking fabulous, and might be tempted into the Channel presently.

She is an absolute stunner. A friend and I discussed buying her together, he then owned a Kaufman 50. Pasha was a bit big (as was his Kaufman) and our ideas only progressed as far as sailing round her.

Jonathan

 

[TiggerToo]

If anybody would like to gift me their Boreal 47 because of it fizzing, I'll be round to collect it pronto.

no jumping of the queue. Please. I was there first.

(plus, they don't fizz)

 

[veshengro]

A yarn about fizzing Aluminium yachts. This may be total cobblers and as I have the technical skills of a small Lettuce, it probably is, but may have some facts hidden within. I was wintering at Sliema, Malta, once, and a story went around that an Aluminium yacht had been pulled up the ramps round at Manoel Island because she had once again been seen to be getting lower in the water over a period of time..
This yacht was French built, hard chine aluminium and was infrequently used as a sort of holiday home, tucked away and rarely visited amongst the other boats that seemed to live permanently round by the Island at that time. Rumour had it that when people investigated the cause of her leaking, after much searching a small circular hole was found through the hull behind where the outlet pipe for the Heads connected to a seacock. A little corroded 'flap' of metal stood up, pushed inwards by the outside water pressure and on investigation a circular flat Battery of the Button Cell type was found embedded in the corrosion flap.
Those who knew, or thought they knew about such things explained to us lesser Mortals that the galvanic action of battery/ Aluminium and sea Water over months would have allowed the battery to eat through the thin Aluminium hull...
Fitted in the deck head of the Heads compartment was a power vent which operated on such batteries. It was assumed that at some time, probably at battery change time, one had been lost and become wedged where it eventually caused the leak.
A possibility or just a yarn to excuse a failed seacock perhaps?

 

[Motor_Sailor]

When I started racing aluminium boats in the 70s, everyone had to remove all their loose change from their pockets and only take folding money on board. We were warned that if a single cupro-based coin was dropped and found it's way into the bilge, it would eat through the hull plating faster than we could launch the liferaft. This was about the only thing that would get you banned from the crew. Well, apart from the alledged carnal intimacy with the owner's dog that saw one Australian foredeck crew member sent packing.

At the time, I'm sure they're were no end of beer fuelled expert opinions to promote this theory, but I've never heard of a first hand account of it ever happening. Further more, I've never seen aluminium boat owners frisking their crew for loose change since then, unless it was to buy another round. As in all things, it's good to see that familiarity and some knowledge can banish ignorance and superstition.

 

[TiggerToo]

This is all very interesting.

It reminded me of that other thing, Osmosis. We were all very concerned once. Is this still "a thing"?

 

[Roberto]

At the time, I'm sure they're were no end of beer fuelled expert opinions to promote this theory, but I've never heard of a first hand account of it ever happening.

Besides, most (all?) modern light alloy sailing yachts bilges are coated (epoxy and/or insulation), no possible contact.
Actually, more danger might come from stagnating salt water against bare aluminium.
Alu is surely not a material for a careless owner or electrical wires hanging all over the place, but if properly taken care of it does not cause any problem, as witnessed by hundreds of happy owners.
Once I was after a Garcia Nouanni, boat about 35/40 year old with a sound hull but all the rest showing its age, it was bought by someone else, completely stripped of everything, interiors rebuilt etc came out a jewel, even better than new.

 

[geem]

.......................... .......

Besides, most (all?) modern light alloy sailing yachts bilges are coated (epoxy and/or insulation), no possible contact.
Actually, more danger might come from stagnating salt water against bare aluminium.
Alu is surely not a material for a careless owner or electrical wires hanging all over the place, but if properly taken care of it does not cause any problem, as witnessed by hundreds of happy owners.
Once I was after a Garcia Nouanni, boat about 35/40 year old with a sound hull but all the rest showing its age, it was bought by someone else, completely stripped of everything, interiors rebuilt etc came out a jewel, even better than new.

It's interesting that all the cosmetic issues on Ovnis that I have seen ( blistering paint on deck mainly) has been resolved on the Allures yachts by marrying an ali hull to a grp deck and superstructure. I wonder what the deck to hull joint is like? The paint problem of aluminium doesn't exist on these boats as they have the plain unpainted dull grey hull. They look pretty good when new but the older one anchored near us at the moment is an acquired taste, shall we say. Certainly past its prime.

 

[Kukri]

.......................... .......

It's interesting that all the cosmetic issues on Ovnis that I have seen ( blistering paint on deck mainly) has been resolved on the Allures yachts by marrying an ali hull to a grp deck and superstructure. I wonder what the deck to hull joint is like? The paint problem of aluminium doesn't exist on these boats as they have the plain unpainted dull grey hull. They look pretty good when new but the older one anchored near us at the moment is an acquired taste, shall we say. Certainly past its prime.

I know, from a ship repair yard point of view, what the steel hull to ali superstructure joint on the “Canberra” was like…

 

[noelex]

There is no perfect boat building material, but aluminium is hard to beat.

However, it does not suffer fools gladly, particularly in relation to the installation of the electrical system. Sadly even many marine professional that have not dealt with aluminium boats don’t appreciate that the wiring system needs to be completely different to a non metal boat. Owners need to know the correct wiring practices and inspect any work done.

26 faults on the leakage current test instrument is terrible. There should never be any fault shown in this system, nor I have I ever seen one in 16 years of owning aluminium cruising boats.

 

[Bajansailor]

Actually, more danger might come from stagnating salt water against bare aluminium.

Re the ally cat in my avatar photo - she is now 22 years old, and still going strong, carrying passengers on snorkelling cruises on the west coast here.
However she had a problem last year.
Her deck hatches (plastic, and original) have been leaking (just drips) for a long time. Folk would go snorkelling, come back on board dripping wet, and some salt water would leak into the hulls. The previous owner told me that he used to ensure that his crew mopped out the hulls regularly, however this had not been done for some years with the new owners. She was laid up for a long time during Covid, and this might have been an aggravating factor as well.

Anyways, I got a call last year from a chap at the yard here that built her - they had been asked to do some repairs to the aluminium.
There was a neat round hole in one hull which had allowed part of the hull to flood - thankfully there are 3 watertight bulkheads in the hulls, so it did not flood totally.
And when we went to investigate the other compartments in both hulls (they all had leaky deck hatches), we found some very neat little heaps of salt directly under the hatches, where salt water had dripped down slowly, and then evaporated. And underneath each little pile of salt was a corrosion pit - the deepest was about 3 mm, in 6 mm hull shell plating.
Re the hole in the hull - maybe this was just due to salt, or maybe somebody had dropped a copper coin in the bilge accidentally - if salt on it's own can cause deep corrosion pits, then I think there is a good chance that a coin could eat it's way through over a period of time.
I was advised by a naval architect friend who is very knowledgeable about aluminium construction to have the area with the hole and the areas with the pits cropped out and new sections of plate welded in, rather than simply welding up the hole and the pits, and the original Builder's yard subsequently did a good job of this.

 

[Tradewinds]

.

Going further back into the mists of time, back to 1949 in fact, the fabulous Laurent Giles reverse sheer Class 1 offshore racer “Gulvain” is ashore at SYH. I think she may be the original aluminium alloy yacht?

Looking a little sorry for herself nowadays. Hull not in the greatest condition (all imo).