Steel hulls in the PNW?

[Porchhound]

I've seen a custom steel hull boat (1980s vintage) for sale in Washington. Not knowing if saltwater is more corrosive on steel, but suspecting it is, anyone have experience with a tin can in that environment?

 

[slowgoesit]

Like most anything, it's about condition and the owner's investment in keeping the vessel maintained.

Steel boats don't have the general acceptance in the US that they have elsewhere.

You may want to put out some feelers on obtaining insurance as well. It may be difficult to obtain on a 40 (ish) steel boat here in the US. Best of luck in your search!

 

[Ken E.]

Many more steel hulls in Europe, and the Dutch and Germans build nice ones.

 

[tiltrider1]

Steel, aluminum, and wood all require special attentions in salt water. It’s no different in
the PNW. If the boat was cared for it’s not an issue.

PNW gets less sun and a lot more rain. When looking at PNW boats you find a lot less Sun damage but you need to be more concerned with rain leaks.

Rain leaks are not just interior cosmetic issues. You can end up with structural defects in decks and cabin structure. Hard to believe but leaking rain water is one of the biggest causes of rusted out fuel tanks.

 

[Slowmo]

Steel is common on commercial vessels in the PNW. As others have said it's common in other parts of the world, Dutch yachts are almost exclusively steel. Yes it can rust but with normal maintenance that's seldom a problem. For a yacht the issues I've heard about are that it transmits cold and noise even more then FG, which transmits much more than wood. The cold transmission will result in 'sweating' inside the hull. Insulation is commonly used on steel hulls to both keep them warm inside and to control the sweating. There are several insulation routes, including spray foam and insulation boards with an airspace behind to allow condensation to drain the bilge.

 

[dannc]

A key issue with a steel hulled boat is how was the hull interior treated. Was the hull painted? Surely it was but you never know. The hull should be prepped per the coating specifications, which is often to blast the steel to white or near white condition, and apply the coating in within a given temperature range soon after blasting to prevent rust appearing.

The hull should be insulated. Often it is sprayed foam, which can be good or bad, depending on the foam used. The good thing about spray foam is that it will prevent air getting to the steel which can cause condensation which you do not want on a steel hull, even if coated correctly. Only using board insulation that is used in home construction is not going to prevent air from getting to the steel hull. Another option, which was done on the Dashew's FPBs, was to use Armaflex which is a neoprene type of insulation that is applied to the hull. It provides good insulation and keeps air from getting to the hull. It is expensive and time consuming to install though.

I saw one build where Armaflex was use to insulation the hull just enough to prevent condensation, I think it was only 1 inch thick, and then rock wool was used to provide the rest of the insulation. The advantage of this method is that the rock wool is cheap to buy and install, and it can be easily removed if work is need on something in the insulation or the hull itself. The glued in Armaflex is not so easy to remove.

Later,
Dan

 

[klee wyck]

I have owned both steel(2) and FRP vessels in very salty water. My bias regarding ease/cost of maintenance and longevity still favors steel.
If I were to pick one boat from all of those owned by members of this forum that I would fully expect to see in great (non-waterlogged and non-delaminated) condition plying these waters fifty years from now, it would be DELFIN.
Pasted below is a quote from its owner stating unequivocally that it takes eight hours per year to maintain her coatings in excellent condition over the last twenty years. That matches my experience and I do not spend less time or money doing the same on Domino(frp) so far.

A properly coated steel boat doesn't present those problems. I spend less than 8 hours a year keeping my steel boat looking pretty pristine by touching up dings with a Dremel tool and an airbrush, and normal washing. I have no interior rust and no exterior rust other than wear and tear dings I repair. That after 20 years on the paint (Awlgrip).

 

[Ken E.]

I have owned both steel(2) and FRP vessels in very salty water. My bias regarding ease/cost of maintenance and longevity still favors steel.
If I were to pick one boat from all of those owned by members of this forum that I would fully expect to see in great (non-waterlogged and non-delaminated) condition plying these waters fifty years from now, it would be DELFIN.
Pasted below is a quote from its owner stating unequivocally that it takes eight hours per year to maintain her coatings in excellent condition over the last twenty years. That matches my experience and I do not spend less time or money doing the same on Domino(frp) so far.

A properly coated steel boat doesn't present those problems. I spend less than 8 hours a year keeping my steel boat looking pretty pristine by touching up dings with a Dremel tool and an airbrush, and normal washing. I have no interior rust and no exterior rust other than wear and tear dings I repair. That after 20 years on the paint (Awlgrip).

Have you followed the Bering steel boats? I don't know if they are a real company or a couple guys that send a design to Turkey to be built (?) The photos of their interiors look pretty high-end but I'm curious about build quality, particularly what would they would be like long-term, corrosion etc

 

[Lepke]

Steel properly coated and maintained doesn't rust. Epoxy and zinc are the 2 best. I had 2 tugs zinc coated inside and out about 20 years before I bought them. The only signs of rust was where lines and chain wore thru the coating. The coating is easy to repair if you have the spray equipment.
I also built several steel commercial boats in the 1970s and zinc coated inside and out. They're still around and low maintenance compared to painted steel.

Based on steel boats I've modified or repaired, foam will bond to the steel or epoxy and won't cause a moisture buildup when properly applied.

 

[klee wyck]

Have you followed the Bering steel boats? I don't know if they are a real company or a couple guys that send a design to Turkey to be built (?) The photos of their interiors look pretty high-end but I'm curious about build quality, particularly what would they would be like long-term, corrosion etc

Ken,
Since I have some sort of disorder that causes me to be looking at boats virtually all of the time, of course I have run across the Bering line.
Beyond what you point out about the brand being ill defined, I quickly pass on them for another (personal) reason.
They are too vertical for me, just as the Northern Marine line is in frp. I am sure they are fine boats, I am just not attracted to a vessel with significant infrastructure very far above the VCG.
To tie this back to a concurrent thread here on TF, I would expect to the degree that a member has a vessel where the helm and ‘living’ area is 3-5 meters above the VCG, they would also more strongly hold the view that stabilizers are necessary for passage making.
All fine, of course, just a different set of compromises.

 

[GoneDiving]

Steel properly coated and maintained doesn't rust. Epoxy and zinc are the 2 best.

Lanolin also works well and lasts decades. Mine was totally rust free in any area where it was used after 20+ years.

However, getting it back off is a job you wouldn't wish in your worst enemy.

 

[Judy at JWY]

Going back a few years, I gave seminars at TrawlerFest on the pros and cons of the 3 major hull materials (fiberglass, aluminum, and steel). For part of my research I sent a questionnaire to my current steel boat owners, maybe it was 20 of them at the time. In answer to the question of would you buy a steel boat again, all but one said they would only buy steel; the one loner said that he preferred steel but would not be adamantly averse to fiberglass. I was impressed with the responders' loyalty to steel trawlers.

 

[klee wyck]

Going back a few years, I gave seminars at TrawlerFest on the pros and cons of the 3 major hull materials (fiberglass, aluminum, and steel). For part of my research I sent a questionnaire to my current steel boat owners, maybe it was 20 of them at the time. In answer to the question of would you buy a steel boat again, all but one said they would only buy steel; the one loner said that he preferred steel but would not be adamantly averse to fiberglass. I was impressed with the responders' loyalty to steel trawlers.

Thanks for this interesting perspective, Judy. I would like to explore further. if you or others would indulge me.
All things boat are a compromise. My current reservations around steel trawlers are mostly around weight and the concomitant limitations that brings for speed and draft.
The big catamaran has opened our eyes to some of the benefits of 11-12 knots over 8 knots and less draft. We have just a lovely shore side life that we share with our life aboard which is much less than full time. At the same time, there is so many exciting things to see from the water. More things to see than we are willing to commit the time it takes at 8 knots. We still cling to the efficiency and comfort of travelling at trawler speeds and the extremely high L:B ratio of the cat gets us a good turn of speed with efficiency greater than our full displacement steel trawlers. Quite comfortable in a seaway as well without additional equipment to achieve this comfort. That is quite an attractive proposition, and it comes with a draft barely over half of the heavy boats. Also nice.
This brings to mind the long lean concept in a monohull. To stay light and keep efficiency on the menu, this likely means aluminum.
While there are some modern examples in aluminum, there is not a long history that shows they stand the test of time. In addition, the recently reported splitting of the Arcturos hull after an impact that likely occurred at relatively low speed is quite disappointing and may indicate that aluminum may fair no better than frp in this case?
And, even at 4:1 L:B that you could get in a long lean monohull, we will not approach the benefit of the 12:1 L:B we get from the big cat.
The recent thread from a member that just finished a build of an aluminum cat is quite compelling, but also no thirty plus year old examples to check back on for the test of time.
Also, just to be spoiled, I would like a boat that is both functional and beautiful. Bare aluminum is not my cup of tea so the longevity of the coatings may be more of an issue than it is with steel?

I want it all.....

What did the owners of the aluminum boats say when you did your survey? Would they do it again?

 

[Judy at JWY]

"What did the owners of the aluminum boats say when you did your survey? Would they do it again?"

Yes! They said they would buy aluminum again too. But, my aluminum owners are far fewer in number than my steel owners.

 

[Judy at JWY]

Another point about steel boat owners from my perspective: they all fit in what I call the "steel boat owner" mindset.

Almost all of my male steel boat owners (I have sold 50+ steel trawlers so that means approximately 100 owners) are ex-military, pilots, commercial fishing, engineers and combinations of the above. The bios are impressive and include a submarine captain, submarine engineer, a Navy fleet commander, Base commander, Deadliest Catch boatowner, Special Ops, Secret Service, the "Hurt Locker" soldier, etc. These are the guys that will only consider steel.

On a personal note: Don't I have a great job!! I'm so honored to be able to find boats for their retirement life. From the Fleet Commander to the airline pilot, I meet the finest of the finest.

 

[darkside]

The aluminum build KW refers to was my third alloy so I guess I did buy again. The boat we did the most miles on was wood epoxy (cedar). That is a marvelous material for light custom builds but not so popular in the US. I chose both materials because they are light and light is easy to push so therefore efficient. Combine that with 12:1 L:B and that efficiency grows again. Combine that with no energy or drag for stabilization and the efficiency grows again.
But back to the OP the majority of work boats you see in the PNW are aluminum. Usually the commercial guys make good choices for local conditions so there's your answer.

 

[dannc]

Steel properly coated and maintained doesn't rust. Epoxy and zinc are the 2 best. ....

I always wondered if applying spray flamed zinc, that was then coated with Epoxy, was a belt and suspenders approach or overkill?


Later,
Dan

 

[dannc]

Have you followed the Bering steel boats? I don't know if they are a real company or a couple guys that send a design to Turkey to be built (?) The photos of their interiors look pretty high-end but I'm curious about build quality, particularly what would they would be like long-term, corrosion etc

We really don't like the Bering designs and they don't seem to own a yard but find a boat builder. They seem to be very top heavy and follow the new design trend of putting windows/holes in the hull.

I figured we would be better of buying an existing design from a naval architect, or paying the NA to create our own design, and then finding a builder.

Later,
Dan

 

[Delfin]

I always wondered if applying spray flamed zinc, that was then coated with Epoxy, was a belt and suspenders approach or overkill?


Later,
Dan

Not overkill, IMO. The prior owner had Delfin faired before I bought her as a gutted shell, so I've never seen a spot of rust on the hull, and above really only on areas where I've dinged the paint or a fastener caused a breakdown of the paint. I'd imagine that flame applied zinc might be similar to a coat of epoxy fairing compound, and I would think much cheaper. I've had more issues with bubbling under paint on the aluminum superstructure. Either are easily repaired however, once you get the technique down.

 

[Mac2]

slowgoesit made a great point. Make sure you can get insurance for the boat first. Financing and insurance for steel boats over 20 years old gets difficult-nothing to do with the boat, but more to do with uneducated underwriters. Also, a great article about steel boats was in PassageMaker magazine called, "Cold hard Steel". It talks about how important the build process is and coatings used. This is where the experience of the builder makes a huge difference. I'm parked in fresh water, so it would not be fair for me to comment on saltwater, but I can say without a doubt, I understand why steel boats rust from the inside out. The amount of water that collects on the bare metal in the bilge during winter is pretty amazing. Dehumidifiers are a must.

 

[Delfin]

slowgoesit made a great point. Make sure you can get insurance for the boat first. Financing and insurance for steel boats over 20 years old gets difficult-nothing to do with the boat, but more to do with uneducated underwriters. Also, a great article about steel boats was in PassageMaker magazine called, "Cold hard Steel". It talks about how important the build process is and coatings used. This is where the experience of the builder makes a huge difference. I'm parked in fresh water, so it would not be fair for me to comment on saltwater, but I can say without a doubt, I understand why steel boats rust from the inside out. The amount of water that collects on the bare metal in the bilge during winter is pretty amazing. Dehumidifiers are a must.

Spray in foam prevents that, although I sprayed QuietShip throughout first, then coated with 1/4" acoustical cork. I have never seen condensation anywhere.

 

[Mac2]

Spray in foam prevents that, although I sprayed QuietShip throughout first, then coated with 1/4" acoustical cork. I have never seen condensation anywhere.

My boat has the spray in foam. They left a one foot section bare on each side of the keel in the bilge to allow for water to flow to the bilge pumps. I am looking for a paint for this area to help insulate it to minimize the condensation and also help protect the epoxy painted metal. I will look into QuietShip. Thanks.

 

[Delfin]

My boat has the spray in foam. They left a one foot section bare on each side of the keel in the bilge to allow for water to flow to the bilge pumps. I am looking for a paint for this area to help insulate it to minimize the condensation and also help protect the epoxy painted metal. I will look into QuietShip. Thanks.

The name may have changed, as I can't find it online. It was developed for the Navy X class aluminum boats to deaden sound transmission in those tin cans. It goes on very, very thick, like 20 mils. Works great for condensate prevention as well. Basically all you need is something thick to provide a bit of insulation of the cold metal surface from the warmer moist air.

 

[Mac2]

The name may have changed, as I can't find it online. It was developed for the Navy X class aluminum boats to deaden sound transmission in those tin cans. It goes on very, very thick, like 20 mils. Works great for condensate prevention as well. Basically all you need is something thick to provide a bit of insulation of the cold metal surface from the warmer moist air.

That's exactly what I'm looking for! Hopefully I can find something similar. Thanks.

 

[klee wyck]

Both of mine were built in the Netherlands and are bone dry. I am not sure what they were using 30+ years ago for insulation and coatings but it was effective for both sweating and sound. These are quiet, dry boats.

 

[rpackard]

I met a fellow this summer in Meyers Chuck AK. He had just delivered his steel diesel duck across the Pacific. It was about 18 years old and he told me he was taking it to the boat yard in Wrangell AK for a total exterior refinishing. He claimed a steel boat coated with epoxy needed to be refinished about every 20 years.

that is just one data point.

 

[Bmarler]

I met a fellow this summer in Meyers Chuck AK. He had just delivered his steel diesel duck across the Pacific. It was about 18 years old and he told me he was taking it to the boat yard in Wrangell AK for a total exterior refinishing. He claimed a steel boat coated with epoxy needed to be refinished about every 20 years.

that is just one data point.

20 years is about right by my experience. I pushed mine a bit too long and there was a price to pay.

 

[Delfin]

That's exactly what I'm looking for! Hopefully I can find something similar. Thanks.

This looks like the stuff.

https://www.silentcoating.com/sr1000/

 

[dannc]

Kasten has some good information for metal boat including coatings and insulation. He mentions an insulating coating named Mascoat DTM.

This article has some information on insulating coatings, Corrosion Prevention - Kasten Marine Design

Insulation

Many schemes are used to insulate metal boats. Insulation is mentioned here in the context of corrosion prevention mainly to point out that regardless of the type used, insulation is NOT to be considered an effective protection against corrosion. As with anywhere else on a metal boat, epoxy paint is the best barrier against corrosion.
Sprayed-on foam is not to be recommended. While popular, sprayed-on foam has many drawbacks that are often overlooked:

• Urethane foam is not a completely closed cell type of foam. With time, urethane foam will absorb odors which become difficult or impossible to get rid of. This is especially a problem when there are smokers aboard.
• Nearly all urethane foam will burn fiercely, and the fumes are extremely toxic. Blown in foam should therefore be of a fire retarding formulation, and should additionally be coated with a flame retarding intumescent paint.
• Sprayed-on foam makes a total mess, requiring extensive clean-up. The clean-up process actually further compromises the foam due to breaking the foam's surface skin.
• Sprayed-on foam requires that an intumescent paint be applied, both for the sake of fire suppression, and in order to re-introduce the seal broken by the clean-up of the spray job.

A much better insulation system is to use a Mastic type of condensation / vapor barrier such as MASCOAT, which adheres well to painted steel surfaces, as well as unpainted aluminum surfaces. It creates a barrier to water penetration, and an effective condensation prevention system. Applied to recommended thicknesses of around 60 mils, it is effective as insulation. Further, it is quite good at sound deadening, is fire proof, and will not absorb odors. Mascoat DTM is used for insulation, and Mascoat MSC for sound attenuation, very effective on engine room surfaces and above the propeller. Both are effective whether on a steel or an aluminum boat.
These mastic coatings can be painted if desired. In more severe climates the mastic coatings can be augmented by using a good quality flexible closed cell cut-sheet foam to fit between the framing. The best choices among these flexible cut-sheet foams are Ensolite and Neoprene. There are several different varieties of each. The choice of insulation foam should be made on the basis of it being fireproof, mildew proof, easily glued, easy to work with, resilient, and if exposed, friendly to look at. Ensolite satisfies all these criteria. Ensolite is better than Neoprene in most respects, but is slightly more expensive. One brand offering good quality flexible foam solutions for boats is ARMAFLEX.
Styrofoam or any other styrene type of foam should be strictly avoided. Go get a piece at your local lumber yard and throw it onto a camp fire.... You will be immediately convinced. The same applies to any of the typical rigid or sprayed-on urethane foams. They are an extreme fire hazard and cannot be recommended.

Later,
Dan

 

[Snapdragon III]

I have a fair amount of experience with Aluminum boats, and I love them. In my experience they have corrosion problems in 3 areas. The bottom if the epoxy barrier coat is not kept intact. This is fairly easy to prevent, but requires a lot of sand blasting to renew/fix if it is neglected and becomes an issue. Uncoated, integral water tanks that get attacked by chlorine in the water they are filled with. And areas where salt water gets in and sits for a long time/years. They will corrode at the interface of the sitting water and air. Examples on my last boat were a couple of lockers in the aft cockpit that didn't have enough slope, and had a small amount of water sloshing around at the bottom of them for years. On the upside, all the interior aluminum above the bilge looked brand new on my 30+ year old trawler, even though it had no doubt been soaked in condensation thousands of times. There were also zero leaks, and not rotten core, delimitation, etc in the boat. I would buy another aluminum boat in a heart beat, especially if it was unpainted.