When does Steel Make Sense?

[potomac1]

I'm not trying to provoke the ire of the wood boat builders out there, nor do I have the temerity to post this on woodenboat.com, but I was looking at some of George Buehler's designs, especially the Diesel Ducks, which seem to lend themselves to steel and I started to wonder, at what point does it make sense to build with steel instead of wood? Does it happen at a certain size or for operating under certain conditions? I would think I would be more attracted to working with wood, but when you get right down to it, how much wooden boat building is really woodwork? Multiple coats of epoxy both sides, fiberglass and epoxy, sometimes both sides, sand forever, prime, paint, etc., etc., etc.. Is working with steel significantly more difficult/ expensive? Mostly just wondering. I really like the look of those Diesel Ducks, though Buehler seems to only find room for only two people on a 40' boat.

[Mr Efficiency]

Steel boats make sense when you hit something hard, or very hard, or go aground in a pounding surf etc. They are definitely more likely to be salvageable. We all know it is better not to get in to these situations, but if the worst happens, it is handy to have that extra survivability.

[michael pierzga]

Steel boats are heavy.... Small heavy boats rarely perform well. Small boats made of thin plate steel to compensate seldom have a happy, low maintenance service life. If you're a welder with a pile of steel plate out back..go for it... with good craftsmanship and attention to detail , steel works .

If you re starting from scratch ,consider another build material for small craft. Epoxy, plywood or strip and cloth is well proven , lightweight with many inexpensive, well drawn plans available for amateur build.

To produce a good steel boat....Have no doubt that the build process will be total sensory assault... cut, weld, grind, sandblast, prime fair, prime fair, prime fair........all with steel slivers in your shoes.

[peter radclyffe]

steel is a good idea, it needs less skill & is much stronger

[michael pierzga]

Less skill ???? Sorry...I wont agree. Ive been working with metal boats all my life. Very high Attention to detail during the build and fit out are needed to produce a durable long service life metal boat. Stray electricity, dissimilar metals, poor coating adhesion....the list is long. Plastic is very tolerant of poor craftsmanship and poor maintenance.

Steel requires high tool up investment...plastic boats can be built with a grinder, sandpaper and common hardware store tools and supplies.

Im presently preparing to haul a well built metal boat for bottom sanblasting ,epoxy prime and superstructure refinishing....the cost will make your eyes bulge. This maintenance cycle is repeated every 5 to ten years on a metal boat...never on a plastic boat.

[CDK]

The following small tragedy took place here last week.

An enthusiastic young fisherman decides to take a major step towards a brighter future, applies for a $ 45000 loan from a local bank and buys an 11 years old 26 ft fishing boat with radar, navigation, hydraulic winches and almost 2 miles of nets.
He doesn't yet have a suitable mooring, so he temporarily uses an empty spot on the small crafts jetty, next to the new speedboat of a dubious villager without legal income, suspected of involvement in several criminal activities.

Last Saturday at sunrise, the speedboat lies at the opposite shore, reduced to a wreck and still smoldering. Shortly thereafter, the hull of the fishing boat is reported several miles out at sea, totally burnt out.

According to the preliminary police report, the fire started in the speedboat and the fishing boat was collateral damage. There are still several unanswered questions, like who did it and why the fishing boat was found so far away from its berth while the tide had been rising.

The young guy now has debt he can never repay and no insurance, so no boat.

Steel would have made sense.

[Poida]

I used to see it but not so much now, businesses with a bit of land available and welding gear make themselves a steel boat.

They make the hull and there it sits year after year.

I can only assume that when they finish the hull, it needs sand blasting and painting.

But here sand blasting laws don't allow you to sand blast outdoors unless you make a tent over the site and it then becomes a very expensive exercise.

Besides that steels too heavy it will never float.:rolleyes:

[Mr Efficiency]

If you obey every law on the books to the letter ( re sandblasting in this case ) you will do your head in. Apply a bit of commonsense, make sure the dobbers are on holiday and away you go. :D

[michael pierzga]

I personally cant see any advantage to steel for a small craft. Big boats....70 ft plus medium displacement , yes.

If you must build metal...choose aluminum for small craft, have the components pre cut...then asseble. You will get a durable small craft .

[Mr Efficiency]

I guess steel with less carbon, heading in the direction of pure iron, would not be so prone to rapidly reverting to the oxidised state. Trouble is strength goes down with decreasing carbon. I know the old soft corrugated iron didn't rust likes its 'springy' modern counterpart.

[peter radclyffe]

Less skill ???? Sorry...I wont agree. Ive been working with metal boats all my life. Very high Attention to detail during the build and fit out are needed to produce a durable long service life metal boat. Stray electricity, dissimilar metals, poor coating adhesion....the list is long. Plastic is very tolerant of poor craftsmanship and poor maintenance.

Steel requires high tool up investment...plastic boats can be built with a grinder, sandpaper and common hardware store tools and supplies.

Im presently preparing to haul a well built metal boat for bottom sanblasting ,epoxy prime and superstructure refinishing....the cost will make your eyes bulge. This maintenance cycle is repeated every 5 to ten years on a metal boat...never on a plastic boat.
excuse me, i did'nt mean less skill than plastic

[daiquiri]

The young guy now has debt he can never repay and no insurance, so no boat. Steel would have made sense.
I'm not sure about that, CDK. If the boat was so close to the fire, it would probably start to burn anyways, because of the temperature rise in the cabin. he The steel structure would act like a mirror for the radiant heat, reflecting it back inside the cabin, and the heat buildup would soon make wooden furniture, lining and other flammable stuff catch fire.
Just think about cases of fire on-board steel cruise ships - it's impressive how big and extensive the damage can be and how difficult it is for firefighters to put the fire under control.

The only solution, in this case, is not to have anything to do with certain kind of people... ;)

[cthippo]

The only solution, in this case, is not to have anything to do with certain kind of people... ;)

Even parking next to them.

As the Cargolaw guys say, Ship Happens!

[JLIMA]

To me steel makes sense only when the use/abuse the vessel is going to receive in the performance of her duties would wreck other building materials (tugs, barges, icebreakers and fishing boats): the operating environment is particularly hostile (ice, high probability for hard and repeated grounding in less than nice weather on a less than nice shore, and even then steel might not survive in all cases): the vessels size does not permit the feasible use of other materials: warships (excluding mine ships, that should properly be made with as little metal as possible.)

These are a few of my opinions and I'm sure someone will point out that there are 90+year old wood tugs and a good many wood and fiberglass fishing boats around and fishing, however I was not talking longliners sieners and the like, more trawlers, dredgers, and other trap fisheries boats, whose gear would really damage other materials.

On a note related to CDK's post about the small tragedy I've seen fire sweep across a portion of the local fishing fleet and severely damage 7 or 8 boats so I don't think the comment on the steel hull makes them any more or less resistant when tied next to a vessel on fire just possibly more likely to be salvageable. I've also seen a kind of comical small tragedy a good few years ago.....3 scallop boats were rafted to a single mooring out in the harbor all 3 were being extensively overhauled (read hatches open) when the middle vessel began to really take water, putting enough list on the other two to just barely submerge the accesses to the crews accommodations and soon they too were on the bottom. very interesting to watch as it was Sunday and there was no one aboard yet, all three were soon re floated to finish their over hauls and back to service. (that last part had nothing to do with steel hull or not as 1 was an old woody and she was like her steel cousins non to worse for the wear....

[CDK]

I'm not sure about that, CDK. If the boat was so close to the fire, it would probably start to burn anyways, because of the temperature rise in the cabin. he The steel structure would act like a mirror for the radiant heat, reflecting it back inside the cabin, and the heat buildup would soon make wooden furniture, lining and other flammable stuff catch fire.


An old friend of mine who was an insurance broker said the only thing that probably needs no fire insurance is a concrete slab under water, but he advised to insure it anyhow.

In the case mentioned there would have been extensive damage to the wheelhouse of a steel boat and all the nylon nets on deck would be gone, but there would at least have been a hull and an engine left.
Now the nets accelerated the fire, then the deck caved in, exposing the three fuel tanks and the large Iveco turbo diesel.
The only salvageable items are the bronze prop and a large stainless hydraulic winch that lost its foothold when the deck burned, so it dropped overboard in an early stage.

[daiquiri]

In the case mentioned there would have been extensive damage to the wheelhouse of a steel boat and all the nylon nets on deck would be gone, but there would at least have been a hull and an engine left.

I agree that something would be left after the fire, but the question is - would it still be usable? We are talking about residual mechanical and corrosion resistance after the fire, which is a foggy area of our knowledge because it is very dependant on structural loading, time-temperature curve during the fire event, and even on materials which happened to be close or in contact with the steel structure. A series of heat treatments occur to a steel during the fire, when temperatures can reach 1000 °C (orange heat) and more. They can be any combination of annealing, tempering and quenching (due to firefighting water jets), carburizing etc.
In few words, before the fire breakout you have a structure made of a well-known and certified steel. After the fire, only lab technicians might tell what other kind of steel did it become and is it still usable as a marine structure.
But it is also true that high-strength alloy steels are much more likely to change their residual material properies than a mild carbon steel under these conditions - fortunately so, because the latter ones are commonly used for boatbuilding.
Cheers!

[Poida]

Daiquiri, I think you will find that a steel that changed composition due to heat would not be used in a boat because the welding of the plates would also change it. You would be looking at a low carbon steel that can't be heat treated.

[cthippo]

Historically there have been any number of vessels which have been completely burned out and were rebuilt. Many remained in service for decades thereafter, which tends to indicate that the damage to the steel is not necessarily fatal.

[daiquiri]

Poida & Cthippo,
I never said otherwise, on both your points. It suffices to take the historical example of many steel warships damaged in battle and then rebuilt. But I was considering the size too. On a big ship a fire can leave extensive damage, but the remaining intact part of the structure can still be so big to justify a repair.
In the case of a small fishing trawler the fire can easily involve the whole structure, imho, making very incertain the possibility and convenience of rebuilding, at least until a thorough damage assessment is performed by surveyors.

There's one way we can establish the truth - moore a steel fishing boat with it's load of nets and fuel right next to a FRP luxury yacht of a local mafia boss, burn the FRP boat and see what happens to the steel trawler. :P

[CDK]

There's one way we can establish the truth - moore a steel fishing boat with it's load of nets and fuel right next to a FRP luxury yacht by a local mafia boss, burn the FRP boat and see what happens to the steel trawler. :P

An interesting experiment Daiquiri, but our bay at present is unsuitable. It is unbelievable how many officials make excursions to the crime site. After the local wizzards, police, fire brigade, harbor masters and insurance people, now is the time for delegations from the mainland.

I forgot to mention that there also was a small frp rowing boat next to speedboat: the only damage there was the scorched hood of the outboard.

The event happened between 18.30 when I was outside to say goodbye to our dinner guests and approx 23.00 hours when I closed the entrance gate of our property and noticed that two boats were missing. I assumed the fishing boat was on an -illegal- fishing trip. There was a faint red light near the opposite shore of the bay, but no smoke or smell, so nothing alarmed me.

[daiquiri]

CDK, I am tempted to hijack this thread and to ask you if you can advice a good red wine from your zone, I think they have the renown Plavac Mali grapes down there... Of course I will not hijack this thread, but if you have something to say on that regard, please feel free to do so. ;)

Back on track... From Diesel Duck 41 on (in terms of size) steel hulls with aluminum superstructure can be made with competitive weights and structural resistance with respect to wood or frp. We are talking about displacement motorsailers where some added weight will not make too much damage in tems of speed and fuel economy. You will loose maybe around 1/4 of a knot for each additional ton of weight, for the same power.

Steel does require a good craftsmanship during both design and assembly phase, as M. Pierziga has mentioned in the post #5, including some additional precautions when designing and installing the electrical system.

Cheers

[potomac1]

Thanks all. Thanks daiquiri. That's pretty much what I was wondering. It seems like it doesn't make sense for a smaller boat, but these larger displacement boats are designed around an awful lot of weight. Anyone taken a look at the Buehler designs. His layouts are clearly by and for people without kids (at least at home), but I really like the look of the ducks.

[CDK]

CDK, I am tempted to hijack this thread and to ask you if you can advice a good red wine from your zone, I think they have the renown Plavac Mali grapes down there... Of course I will not hijack this thread, but if you have something to say on that regard, please feel free to do so. ;)


I'm afraid I have to disappoint you Daiquiri.
The spot where our house was built, once belonged to an 80 ha vineyard abandoned several decades ago when the Italians imported deer and the local farmers didn't immediately fence off their properties.
Since then, the "maquis" shrubs have taken over the valleys and there has been sheep farming. A few years ago the government started an olive program by subsidizing cleaning the shrubs, free olive saplings and 10 year tax exemption if the plantations are successful.
By the time the olives are old enough for a good yield, there will be an enormous over-capacity....

Plavac is still a popular wine, but the origin can be Istria, Dalmatia or some inland chemical plant. My personal favorite is "Tga za Jug" from Macedonia.

[Submarine Tom]

If I had been thinking I would have built my boat from steel instead of glas-on-ply but not for reasons of fire. Most boats sink if the fire is fought effectively but for durability alone. From beaching to dock abrasion to log strikes to rotting wood to delamination to...

-Tom

[MikeJohns]

Comments such as "Steel boats are heavy" need qualification.

It's more sensible to consider the displacement length ratio before deciding on or judging a hull construction material. Small steel boats are usually heavy because it's one of the sensible materials to build small heavy boats from.

Once a boat gets over around 40 feet and medium heavy displacement steel makes as much sense as any other material and arguably has some considerable benefits at times over other materials. I'd include ease of Construction, Durability Repairability and material cost. Why would you ever build a medium-heavy or heavy displacement comfortable cruiser out of expensive light weight materials ?

Put money into a good initial paint coat and then maintain that coating and a well designed steel boat will last hundreds of years. Part of that maintenance means removing the internal linings and checking the interior paint job from time to time too. That's where seamless glued in fit-outs should be avoided in favor of more easily removed ceiling.

Trad timber vessels can have have charm and quality, but in reality the commercial world moved to steel, alloy and composite designs for very good reasons. And also consider that wood in composite form produces a stronger more watertight and stiffer vessel than trad planking can.

[Quatsino Boater]

make mine steel! as a professional welder there is no dificulties in fabrication. I have also fabed small diving tenders in aluminum as well as doing maintenace, repairs and mods to fishing boats. I am retiring soon and I am also looking at the duck series and a few other designs.

Living and working in the pacific north west in industry at the waterfront you can see the direct benifit of steel in fishing vessels, steel long liners and draggers. Steel tugs, even small sidewinders or boom boats under 20 feet! Plus local small friegters. All these vessels navigate tricky coastal waters with + 5 knot currents, 12 to 25 foot tides, rocky shores and bottoms with a ton of dead head logs in the neiborhood of 2 to 5 feet in diameter and up to 60 feet in length. To me in these conditions steel makes sence. Typaclly a 200 amp AC/dc welder , Either portable or 220v /575v shop. Grinders and a cutting outfit plus all the riggin for lifting.
.

Aluminum is nice but a higher skill level ,greater cost in material and a greater outlay in equipment would only benifit you if you were to make several boats at a time. Skill range from plasma cutting , TIG and MIG welding. Fabrication problems include distortion control and oh hot shortness durring welding. A breeze in the shop or outside blowing your shielding gas makes for a few minutes of swearing and grinding too! Any boat in aluminum will require a real MIG welder not a 1000 dollar toy. A miller 30 amp spool gun even used with an AC control box will run you 1500 bucks and then you need a 60 to 100 % duty cycle welding machine that will give you at least 250 amps. If you go TIG as well for the small parts you will need a flow meter hose , tig torch set , around 300 bucks then a AC welding machine with High freqency and a foot controller as well. Better think of a 300 plus amp machine because of the surface aluminum oxide layer you need a lot of jam to start the weld puddle and then back off the amps to continue and finish the weld. So skill level is a wee bit more than steel. Aluminum is about 3 to 5 times the cost of steel depending on the latest pricing. Bottom line leave the aluminum to the professionals. Typically I used a deisel 300 amp DC welder with a Miller 30 amp spool gun, Ac controller for dock work . Running .035 or .045 5356 wire. A 500 amp miller arcrafter AC/DC shop welder with High Frequency and a food controller , A 80 amp plaz, circular saw, A9 cutting fluid and jigsaws. plus all the riggin for lifting.

As far as looks, I have gone onboard several steel draggers and longliners that were exceptionally well kept and built. One such dragger was built and hailed out of Victoria and I asked him you want me to weld what? The boat was so faired and rounded I swear I was on a plastic boat. It was amazing. He must have had stock in a fairing compound company or owned his own rolls but everthing was rounded! Again amazing!

In my humble opinion and I kow I'm a newbie to this forum, If you really want o use your boat day after day running in all weather with tides, currents and debris in the water. Tie up to a log boom for lunch, Tie up to a typical logging company dock for over night or weather out a storm I would use steel. If you want to spend your time at the dock and a quick evening cruise with cocktails around the bay, a plastic boat with a nice shiny white gleam, smoked glass and coutesy cockpit lights might be better. Oh by the way dried salmon/halibut blood is a real chore to clean on texturized white plastic. My current plastic boat has spider cracks that I need to constantly tend to. Mainly around high stress and radical changes in direction in lighter roof sections where the radar arch bolts on . Uggg Black rubber tire marks from the gov. docks! Bird droppings when the blackberries are in season!! Scuffs, dings, gel coat repairs , waxing and polishing.So plastic boats have maintenance issues too.

[gonzo]

One other thing to consider is the area of operation. In fresh water, the plating can be a bit thinner and corrosion is less of a concern.