[PCP]

I tend to view materials as useful for a particular application. Aluminum may be useful if you are particularly concerned about weight. It appears the application for this thread is a cruiser. Seems unlikely justification for aluminum.

Aluminum structures need careful testing to quantify their fatigue life. The Airline industry makes use of an incredible quantity of aluminum for wings, landing gear and body. And they characterize the fatigue strength and resulting life with sophisticated structual test systems than often contain 100s of actuators. Quite impressive test systems.

So do these aluminum boat manufacturers subject their hulls to similar fatigue tests? Probably not. These multi-channel test systems cost tens of millions of dollars. Well beyond the wallet of the boat builders.

We have all seen the fatigue cracks on masts and booms on sail boats. Many of us have small aluminum boats with numerous fatigue cracks in various load points. And some of us have seen aluminum hulls from older boats with numerous cracks.

Even with the incredibly careful testing the airline industry subjects their planes to, they have fatigue cracks in the structures. Careful inspections catch most problems before the plane falls out of the sky. The automotive manufacturers perform similar fatigue testing.

If weight is the major concern, yes you might like an aluminum hull.. but really.. a cruiser is hardly weight sensitive. On the contrary, the heavier boat will be invariably more comfortable which cruisers eventually learn.

Wood rots, steel rusts, aluminum cracks/corrodes, fiberglass coring fails. Each material comes out on top for some particular application.
Take your pick.. just understand the limitations..
Bryce

Bryce, aluminum are not very used in the US to build sailing boats but it is in France and Holland and the guys that use them are long range voyagers. Yes Aluminum is more difficult for an amateur but almost all those boats are professionally built. Normally amateurs buy the hulls and cabins and make the interior but there are many reputable brands making small production aluminum boats for 30 years and they are all there on the water.

A good way to access durability and the way a boat keep its good shape without a ton of needed expensive work is the value a boat has on the second hand market. Go there and look at the prices for a 15 or 20 year old steel boat and for the prices of aluminum boats of the same age. Compare their value: Sure, a aluminum boat is more expensive from the start but not that much.

Is also for that reason that there are many shipyards making small production aluminum boats and not one that I know of making relatively small steel boats, the size of the ones we sail.

Regards

Paulo

 

[Brent Swain]

One should not confuse resale price with resale value. Resale price is what you can get for a used boat, but resale value is the difference between what you can get for her, and what she cost you in the first place.
Its not uncommon for people to spend an extra $40K on a boat, to increase the resale price by $20K, a net loss of $20K.
Many of my boats have sold for many times what they cost the original builder. The more you spend on her, the less the gap, until it becomes a money losing proposition.

I have pulled together 37 small steel boats.

 

[SloopJonB]

Brent, you are unusually well qualified to provide a real world answer to the performance question of steel boats.

What is your typical miles per day average on your Pacific crossings in your own boat?

 

[PCP]

Brent, I am not saying bad things about steel boats. They are what they are: strong, heavy and slow if they are not really big.

You have a way of building solid boats in a way that is not expensive and that makes it simple for an amateur to build for not much money and I appreciate that and certainly you have a market for them. But if you go to a shipyard with a more complex design of a 40ft boat that can be built in aluminum or steel (some designs can) the difference in price should be about 25% less for steel. In 15 years the difference in value of the two boats will be much more than those 25% difference and besides that even much more cheaper the steel boat is going to be much more difficult to sell.

Regards

Paulo

 

[BryceGTX]

Bryce, aluminum are not very used in the US to build sailing boats but it is in France and Holland and the guys that use them are long range voyagers.

The first aluminum boats were built in the US in the late 1950s. Almost any boat of any shape or size has been built since then. However, fiberglass became the material of choice due to its significant lower maintenance and higher durability.

Currently, millions upon millions of small aluminum fishing boats and high performance bass boats are produced where weight is the critical issue because they are transported by trailer.

You would find it difficult to convince the American market that aluminum would be preferably over fiberglass for boat construction. There are way too many boaters that are familiar with the fatigue issues involved with aluminum boats.

Yes Aluminum is more difficult for an amateur but almost all those boats are professionally built. Normally amateurs buy the hulls and cabins and make the interior but there are many reputable brands making small production aluminum boats for 30 years and they are all there on the water.

There is no doubt in my mind that the US produces magnitudes more production quality aluminum boats than the European boat industry. These guys are not amateurs.. they are production boat companies.. Lund for example. Various companies since 1950s.. closing in on 60 years.

You cannot convince us that because a boat is 30 years old, it is a good construction material. There are 100 year old wood boats still afloat that would seem to indicate wood is better than aluminum.

Is also for that reason that there are many shipyards making small production aluminum boats and not one that I know of making relatively small steel boats, the size of the ones we sail.

My discussion is not steel versus aluminum, rather it is should anyone use aluminum for large boats for any other reason than for the express requirement of light weight.

You have not addressed the durability question, possibly because the European industry is only 30 years old compared to the US industry of nearly 60 years experience.
Bryce

 

[xymotic]

The first aluminum boats were built in the US in the late 1950s. Almost any boat of any shape or size has been built since then. However, fiberglass became the material of choice due to its significant lower maintenance and higher durability.

Currently, millions upon millions of small aluminum fishing boats and high performance bass boats are produced where weight is the critical issue because they are transported by trailer.

You would find it difficult to convince the American market that aluminum would be preferably over fiberglass for boat construction. There are way too many boaters that are familiar with the fatigue issues involved with aluminum boats.

There is no doubt in my mind that the US produces magnitudes more production quality aluminum boats than the European boat industry. These guys are not amateurs.. they are production boat companies.. Lund for example. Various companies since 1950s.. closing in on 60 years.

You cannot convince us that because a boat is 30 years old, it is a good construction material. There are 100 year old wood boats still afloat that would seem to indicate wood is better than aluminum.

My discussion is not steel versus aluminum, rather it is should anyone use aluminum for large boats for any other reason than for the express requirement of light weight.

You have not addressed the durability question, possibly because the European industry is only 30 years old compared to the US industry of nearly 60 years experience.
Bryce

My Steel Ketch is 74 years old.

I just like saying that

 

[AlaskaMC]

You have not addressed the durability question, possibly because the European industry is only 30 years old compared to the US industry of nearly 60 years experience.
Bryce

Bryce,

I agree with you that there are tons of aluminum boats produced in the US and have been for years. In fact, in Alaska, they are hands down the most common build you see when it comes to offshore commercial sport fishing boats and jet boats. I can definitely see the benefits up here for one when it comes to durability. Steel as well, but the weight issue is real.

I guess I am confused by your post though, are you saying that aluminum is a only a viable choice when weight is the primary issue? I would say that lots of duel diesel fishing boats would disagree. In fact I love the idea of the French cruising aluminum sailboats and would love to be able to afford one. I guess I am not sure I get the point you are making above. Sounds like you are bragging up our aluminum boat industry (I agree) but then trashing the material at the same time (and the European boat industry to boot).

And on a side note, aren't you a snow mobile guy as well?

 

[Stumble]

Lets be realistic here guys, the best material for a boat is an all titanium hull.

Size for size a steel boat is always going to be both heavier and cheaper. However this is just for the hull. Aluminium doesn't need to be painted, so this can be a pretty big cost savings, and because the systems can be smaller (rig, engines, transmission, ect) the difference in cost between aluminium and steel for the entire boat isn't really as high as the cost to just build the hull may imply.

I always find it interesting that people raise concerns about the fatigue life of aluminium, but no one ever raises the issue with fiberglass. Given that fiberglass has the same fatigue problems as aluminium it seems more of a theoretical problem than an actual one, so long as the boat is properly designed in the first place.

 

[goboatingnow]

Europeans have been building aluminium boats as long as the US. But specifically in Sailboats the European market is the largest in the world( and significantly bigger then the US) and hence also accommodates aluminium sailboat construction. The US has little or no experience in metal based leisure sailboats. Its only when you get into super yacht territory do you see some experience.

 

[PCP]

...
You would find it difficult to convince the American market that aluminum would be preferably over fiberglass for boat construction.
..

Nobody is saying the opposite. In Europe fiberglass boats are much more common than aluminum boats and for a good reason: they are cheaper to build for a similar weight. The Aluminium boats are only common and even dominant on the French market in a very small market segment: grand range voyage boats, I mean the ones used to circumnavigate or to sail to faraway places and nobody do that with more frequency than French sailors.

The reason is obvious: the boats are as light as fiberglass boats (and sail as well) and are much more resistant to hull impacts to debris in the water. They can also be beached (much are centerboarders) with much more confidence than a fiberglass boat.

Regarding boatbuilding in aluminum I was referring to the pleasure market and particularly to cruising sailboats. There are in Europe many shipyards that have small production and medium serial production of sailboats. Do you have any on the US, I mean sailboats? There are even more shypiards that have not a serial production but are specialized on pleasure aluminium building.

Regarding the difference in performance, that is a huge one and one that makes a small steel boat really only appropriated to sail on the trade winds and even so a lot worse than an aluminum boat, that can have a similar performance regarding the one of a fast fiberglass boat.

I know what I am talking about. A big part of my sail learning was done (for years) on a 16m steel ketch. I remember how safe and even fast the boat was with a F9 wind but also remember that outside what most would call bad weather, the most we got was motorsailing or small speeds. In fact we only went out with the boat for sailing when all other sail boats were coming to port looking for shelter

An interesting post of a owner of a 43 year old aluminum boat:

quote:

"For some reason there seems to be many stories of disaster, particularly on this side of the Atlantic, around aluminum as a boat building material. These stories normally go like this: "I have a friend, who knows a guy, who has a cousin, that bought an aluminum boat, and after a week in the marina the bottom fell out of her".

The funny thing is that after 20 years of aluminum boat ownership and ten years of being a fairly high profile proponent of the material, I have yet to meet one of these mythical aluminum boat victims.

The fact is that as long as the boat is built out of the right aluminum alloys, and the right welding rod is used (all well documented), aluminum boats last longer and stay stronger and more stiff than boats built of any other material you can think of.

Which brings me to Carina, a McCurdy and Rhodes Custom 48-same designer as our own Morgan's Cloud-that has just won the Newport Bermuda Race for the third time. Thing is, the first time Carina won, the leisure suit was in fashion…the year was 1970.

Carina won again in 2010, exactly forty years after her first win. And then again this year. And you know what Carina was doing between her second and third win? She sailed around the world clocking up 42,000 miles. And while she was at it, she did a few races…like The Trans-Atlantic, The Sydney Hobart and The Fastnet-not exactly known as walks in the park.

One tough old bird that aluminum boat…fast too.

I spoke with Rives Potts, who is not only Carina's owner and skipper, but also runs Pilots Point Marine. Rives has been involved in building and repairing many aluminum boats over the years. He had this to say:

-If an aluminum boat is built of the right alloys and the right welding rod is used, she will last essentially forever.

-The great thing about aluminum is that what you see is what you get-if you have a problem, you can see it.

-He has not had to make any structural repairs to Carina. And she shows no significant corrosion.
She is still incredibly stiff and strong after 43 years of hard voyaging and racing.

-And because Carina is stiff, she is still fast and it is much easier to keep the deck fittings and hatches watertight than it would be on a boat that flexes more.

-When he has seen corrosion damage on aluminum boats-usually the result of a wiring problem or an inaccessible area where debris has lain for years-it is confined to a small area and is easy to repair as good as new by cutting out the plate with a skill saw and welding in new plate. Just make sure you use the right alloy plate and the right welding rod.

-Repairs and modifications to an aluminum boat are easier [that means cheaper too] than they are on boats built of most other materials.

-The only real drawback of aluminum is keeping paint on it. But if the paint job is done right even that issue can be overcome."

Why aluminum is the best building material for sailboats

Well, I would say that the biggest disadvantage is price, but that is another story

Also an interesting well know quote of Jimmy Cornell that after having tried all kindss of boats (and boat materials) to long distance voyage opted for aluminium.:

Can aluminum compete with fiberglass as a production hull material?

Jimmy Cornell's Ocean Cruising Survey, a valuable indicator of trends among world-voyaging cruisers, shows that metal boats are on the increase. A metal hull was the number-one wish of those with other hull materials. "My next boat will be metal..." was heard over and over, particularly by those who were already cruising aboard a metal boat.

It is said among dedicated blue water cruisers in the South Pacific, "50% of the boats are metal; the rest of them are from the United States...."

http://www.kastenmarine.com/aluminum.htm

and some more information about aluminum hulls, none of them regards the problems you mention (maybe you cab say what the marine credible source that sustain your negative opinion regarding aluminum boats):

http://www.berckemeyer-yacht.de/tex_construct.html

http://www.benford.us/articles/boatbuildingmaterials.html

http://www.kastenmarine.com/aluminum.htm

http://www.alumarine.fr/en/advantages-of-an-aluminum-boat.html

Regards

Paulo

 

[BryceGTX]

I guess I am not sure I get the point you are making above. Sounds like you are bragging up our aluminum boat industry (I agree) but then trashing the material at the same time (and the European boat industry to boot).

Steel as well, but the weight issue is real.

The point I am trying to make is that there is an incredible amount of experience with aluminum boat builders in the US. Invariable the reason for building aluminum boats is the weight issue rather than strength. As you (and I) pointed out.
Bryce

 

[BryceGTX]

and some more information about aluminum hulls, none of them regards the problems you mention (maybe you cab say what the marine credible source that sustain your negative opinion regarding aluminum boats):

yacht

Boatbuilding Materials - Articles - Benford Design Group

Aluminum For Boats

Advantages of an aluminum boat

Regards

Paulo

So you are trying to convince us by showing us alumimum boat manufacturers and owners? Your sources are biased..

So what does the US Government say about Alum boats?

"Aluminum weapons systems are in widespread use throughout all services of the military. Unfortunately, more and more failures of aluminum due to corrosion are being reported. "

Aluminum Equipment Failures in Coastal and Marine Environments

How about this 144 footer that failed in 1 month??

"Nichols discovered the cracks in the Jet Cat's hull after the boat's owner, Catalina Express, noticed the aluminum on the boat discoloring. Just a month after the 144-foot boat was launched by Nichols in April, the problem caught the attention of the company's engineers. Metallurgy tests showed that the aluminum was defoiling wherever it was in contact with salt water. Cracks near the Jet Cat's engine room were so large that water had begun to seep into the boat."

Cracks in aluminum boat's hull cause concern at Nichols - South Whidbey Record

Here is what the everyday guy says about alum boats:
"I have a crack in my boat. The boat is a flat bottom boat and the crack is where the side meets the bottom. I am sure that the crack can be welded no problems and stop the leak. I am drawing a blank on who to take it to to have it welded up tho. The crack is about 9 inches long"

Aluminum Boat Repair

Then there is this guy:
"The boat has been in use constantly, most likely with these welds cracked for many years"

Aluminum boat - Cracked welds - Page 1 - 367412

Here is another guy:
"What I found are 17- 2" welds over a 10ft. length from passenger console to bow broken. "

http://www.boatdesign.net/forums/metal-boat-building/broken-welds-7345.html

The Marinette Forum:

"Check the hull first before you decide to weld. Aluminum hull percussion sounding or ultra-sounding can cost $20.00 per foot to find flaws, ask a surveyor who knows this stuff.
If it feels deeply pitted, it's too far gone, see below. A small patch is usually just fine. "

http://www.marinetteboat.com/Metals.htm

Another discussion about older alum boats:
"Many times I have seen older riveted alum. boats crack along and near the rivets. I don't think that the crack can be repaired."

http://glen-l.com/phpBB2/viewtopic.php?f=7&t=4672

This one even has pictures:
"Here are pics of the crack. If anyone can please share on any reinforcement tips and how anyone repaired a cracked aluminum transom. Thanks everyone."

http://www.screamandfly.com/showthr...owthread.php?194262-Cracked-aluminum-transom-need-help-for-repair-reinforcement

Lets see what wikipedia has to say:
"One important structural limitation of aluminium alloys is their fatigue strength. Unlike steels, aluminium alloys have no well-defined fatigue limit, meaning that fatigue failure eventually occurs, under even very small cyclic loadings. This implies that engineers must assess these loads and design for a fixed life rather than an infinite life."

Aluminium - Wikipedia, the free encyclopedia

For every post you can find positive about aluminum boats, I can find a hundred that talk about fatigue cracks in any alum boat of every size imaginable. I am one of those guys with a 12 foot alum/glass fishing boats with fatigue cracks in the alum seats.

Now I can easily also go out and find glowing reports on wood, steel, fiberglass or concrete. But we can also point out the negative aspects of these materials.

I think my most fundamental point is, consider that every building material has some particular issue. Aluminum is no different. The way I see it.. the most attractive aspect of aluminum is its light weight.
Bryce

 

[PCP]

So you are trying to convince us by showing us alumimum boat manufacturers and owners? Your sources are biased..

So what does the US Government say about Alum boats?

"Aluminum weapons systems are in widespread use throughout all services of the military. Unfortunately, more and more failures of aluminum due to corrosion are being reported. "

Aluminum Equipment Failures in Coastal and Marine Environments

How about this 144 footer that failed in 1 month??

"Nichols discovered the cracks in the Jet Cat's hull after the boat's owner, Catalina Express, noticed the aluminum on the boat discoloring. Just a month after the 144-foot boat was launched by Nichols in April, the problem caught the attention of the company's engineers. Metallurgy tests showed that the aluminum was defoiling wherever it was in contact with salt water. Cracks near the Jet Cat's engine room were so large that water had begun to seep into the boat."

Cracks in aluminum boat's hull cause concern at Nichols - South Whidbey Record

.....
Bryce

Hummm, I get your point. It is because Aluminum is a ****ty material for boat building that " 50% of boats in America are built from aluminum". It makes sense

The Advantages of Having an Aluminum Boat |

Regards

Paulo

 

[PCP]

The point I am trying to make is that there is an incredible amount of experience with aluminum boat builders in the US. Invariable the reason for building aluminum boats is the weight issue rather than strength. As you (and I) pointed out.
Bryce

Of curse, everybody knows that a sail boat should be as light as possible and as strong as possible. Light and strong is not an attribute that is good only on sailboats, many other type of boats have advantages to be light and strong and that's why so many boats are built in Aluminum in the US and everywhere.

I guess that everybody knows that weight for weight Aluminum is considerably stronger than steel.

Regards

Paulo

 

[BryceGTX]

Hummm, I get your point. It is because Aluminum is a ****ty material for boat building that " 50% of boats in America are built from aluminum". It makes sense

The Advantages of Having an Aluminum Boat |

Regards

Paulo

No the boats are built of aluminum because the goal was to produce a light boat that could be trailered.
Bryce

That does not make sense an aluminium boat is not lighter than a cored fiberglass boat and a fiberglass boat is less expensive.

You are kidding right?

 

[PCP]

No the boats are built of aluminum because the goal was to produce a light boat that could be trailered.
Bryce

That does not make sense an aluminium boat is not lighter than a cored fiberglass boat and a fiberglass boat is less expensive.

They are made from aluminum because they are as lighter as cored fiberglass boats and stronger. Heavy duty fishing boats are the ones made with aluminum, many used professionally.

Regards

Paulo

 

[BryceGTX]

I always find it interesting that people raise concerns about the fatigue life of aluminium, but no one ever raises the issue with fiberglass. Given that fiberglass has the same fatigue problems as aluminium it seems more of a theoretical problem than an actual one, so long as the boat is properly designed in the first place.

There is a good reason people who know are concerned with fatigue life of aluminum.. because it is aluminums most critical issue. And it fatigue failures are thousands of well documented real-life fatigue cracks that show up in a multitude of aluminum products.

There is a simple solution.. subject your product to fatigue tests. That is what the airline manufacturers and auto manufacturers do.

On the other hand, the fatigue life of something like steel is so well defined that you can build a product, and predict its life with software on a computer.

The way I see fiberglass is that there is not such widespread fatigue failure in fiberglass based on experiences of people. Rather fiberglass failure seems most often due to core failure or impact damage. The study below suggests that fiberglass fatigue might be predicted using steel type predictions.

Although I am sure some structural test engineers would cringe at the test setup these guys used.. its an interesting read.

www.usna.edu/Users/naome/phmiller/fatigue.ppt

Bryce

 

[AlaskaMC]

The point I am trying to make is that there is an incredible amount of experience with aluminum boat builders in the US. Invariable the reason for building aluminum boats is the weight issue rather than strength. As you (and I) pointed out.
Bryce

Bryce,

Actually, that was not my point. Weight AND durability are the reasons aluminum boats are popular in Alaska. Jet boats going up stream in very rocky water, sometimes jumping beaver dams or skimming over shoals that are out of the water for example. And, offshore it is the same thing. Weight AND durability is the issue. These things take MAJOR beatings that a fiberglass boat would not even make it 100 yards from the launch.

Just don't want to be misquoted as I was pointing out that when you want durability and weight savings then aluminum is really one of the few choices.

 

[Tanley]

Captain Q, found this the other day. No affiliation but she looks to be well found.

Balance for sale

As an aside, are you sailing Cayuga lake now? Grew up in that area, beautiful part of the country.

 

[CaptainQuiet]

Tanley, Thanks for the link. That's a big one. Not sure what I would do with all that space. Any idea why they are selling?