Iron fuel tanks - when did they go away?

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oak_box

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I've been looking at older trawlers, and of the ones I could tell, all the boats up through the mid 80's had the black iron fuel tanks.

When did they stop using black iron tanks?
Are fiberglass tanks common?
How do you find out what type of tank is in the boat you're looking at without digging into it? (or is that just part of the fun?)
 
Fuel tanks

Kadey-Krogen 42's up to hull # 60 or so have two Heavy duty 350 gallon fiberglass fuel tanks - one port & one stb. -- made of fiberglass so can never rust out.

On Average KK built about 10 boats a year. 42's were built from around 1977 through 1997 or so. - so maybe 207 built total of the 42's in that approximate 20 year time period. Unfortunately, Later models after hull # 60 or 65 or so went back to the black iron fuel tanks. Probably cheaper.

There may be some other boat manufacturers out there with the same type of fiberglass fuel tanks out there.

Alfa Mike
 
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oak_box said:
I've been looking at older trawlers, and of the ones I could tell, all the boats up through the mid 80's had the black iron fuel tanks.

When did they stop using black iron tanks?
Are fiberglass tanks common?
How do you find out what type of tank is in the boat you're looking at without digging into it? (or is that just part of the fun?)
Click to expand...


Bring a magnet to test if it is a black iron tank.

Other types of tanks can have problems as well if they are not well designed.
I replaced my 35 year old stainless steel tanks due to corrosion. They were mounted on a flat surface without any drainage or ventilation below. Trapped moisture underneath the tanks eventually corroded them from the bottom up.
 
Australian built Rivieras which sell in USA have f/g tanks.
If both so called "black iron"(which I think, subject to correction, is really mild steel) is likely to rust readily,and stainless steel can corrode(? rust, maybe depending on grade), what about aluminum as a preferable material? I know it`s bad for holding tanks as it literally cannot "take the piss" (Australian expression for humorous mockery) due to uric acid.
 
Black iron tanks started to go away with cheaper steel and finally with welding instead of riveting. If the tanks are welded they're steel. If they're riveted they could be iron, but not likely unless they're a hundred years old. Well built steel tanks last a long time. Cared for steel tanks usually last the life of the vessel. Ships and large boats are built with the tanks as part of the hull.
My 1942 steel tanks are doing fine.
 
BruceK said:
Australian built Rivieras which sell in USA have f/g tanks.
If both so called "black iron"(which I think, subject to correction, is really mild steel) is likely to rust readily,and stainless steel can corrode(? rust, maybe depending on grade), what about aluminum as a preferable material? I know it`s bad for holding tanks as it literally cannot "take the piss" (Australian expression for humorous mockery) due to uric acid.
Click to expand...

Aluminium tanks can be ok, provided they are well designed and installed correctly. The killer for them is poultice corrosion.
Marginal Maritime Advice: Poultice Corrosion

Mild steel (aka black iron) can still be used for tanks. Care required is not that different to other metals: avoid designs or installations that can pool water. Avoid contact with materials that will keep the tank moist in places for long periods.

My new tanks in 2013 were made of pre-primed mild steel. Obviously the welds were then cleaned and primed before using an epoxy paint system over the whole tank. They are bedded on nitrile rubber.

If feasible I would choose fibreglass tanks. Probably easiest for a new build. But, if not well made they can develop leaks too.

Pic of tanks after welds primed, and then after full painting. Also old tank, with flakes of rust at bottom. Water entry was rain via vertical slates on ER vents. Water pooled on top of tank to a degree, and then ran down sides. Tank was resting against hull, and developed pin-hole leak after a bit over 30 years.

For inspections pre-survey, just use a camera on a stalk connected to your phone. They are pretty cheap now. Look beneath the tanks. They almost invariably rust/corrode from the outside in.
 

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For a new build Monel tanks are still available , not cheap, but "forever" seldom is.

One advantage of a custom tank is the ability to have a proper fill tube and sump built in.

This means no "fuel polishing" forever and the ability to handle a bad fuel load that contains 1/2 water.

A monel tank with sump will probably not add 1% to the boats cost , but may cut down fuel problems by 99%.
 
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Steel is a good material for diesel tanks. They typically fail because of improper installation or owners not re-bedding deck fills.
 
Larry M said:
Steel is a good material for diesel tanks. They typically fail because of improper installation or owners not re-bedding deck fills.
Click to expand...

Add to the list leaks that allow water to migrate to tank exterior such as - old teak decks, salon windows, port lights, air intakes and bilge water sloshing around.
 
FF said:
One advantage of a custom tank is the ability to have a proper fill tube and sump built in.

This means no "fuel polishing" forever and the ability to handle a bad fuel load that contains 1/2 water.
Click to expand...

I know that a sump is the accepted means of building a tank, able to trap a cup of water or so. But I've always thought that a better way to build a tank would be with the fuel pickup reaching all the way to the bottom. Constantly drawing any dirt or water, which gets filtered out in the Racor. Basically constantly polishing the fuel, like what my old Jimmies did.
 
I had a 1989 Lien Hwa 47 with four steel tanks. The two in the lazarette began to leak in 2008. I had them thoroughly cleaned and coated with POR15 which I believe is an epoxy coating. There was a process involved according to POR. There were pin holes rusting through the welded seams from the inside out. Reading about POR made it sound like this was a long term solution. I had to sell the boat shortly after that and a year later the purchaser called me and asked about leaking fuel tanks. He sold the boat.

Now I have a 1991 Californian with 1/4" aluminum fuel tanks just purchased last July. There are two tanks. 400 gallons in the lazarette and 265 under the master bed. The 265 tank began to leak so I planned on replacing both figuring they would both need it. During the removal process of the 265 I could see that the insides of the tank looked beautiful except in a couple places and when we inspected the outside you could see that corrosion was going outside in. This tank is in a section of the bilges completely enclosed so that no water can get into it or out of it. The manufacturer figured that little rubber pads under the V at the bottom of the tank would prevent any vibration noise. Well there is a water tank on top of the fuel tank and then the bed on top of that. I see the water tank is not original so the old one must have leaked and the water never removed which caused the corrosion at the rubber point of contacts. Good news was the aft 400 gallon tank did not need to be removed because it was elevated above the bottom of the bilges.

So the point of this story is, keep your aluminum tank out of the water and they will last a long long time.
 
Hatteras always built their boats with all tanks being made of fiberglass. Unless you had a gas engine and the ethanol got to them, tank degradation is practically unknown. Just one thing NOT to worry about leaving room for all the frustration caused by having 240v, 110v 32v 24v and 12v equipment onboard......
 
The original Willard 36’s have fiberglass tanks. I have had two different W36’s, both over 50 years old with not a hint of problems.
 
Woodland Hills said:
Just one thing NOT to worry about leaving room for all the frustration caused by having 240v, 110v 32v 24v and 12v equipment onboard......
Click to expand...

I had the same electrical on my Burger and always thought it was such a stupid way to do things. That being said, I don't like American electricity anymore and the next boat will be 230/50Hz - even the appliances are much more efficient :)
 
makobuilders;762295...ll be 230/50Hz - even the appliances are much more efficient :)[/QUOTE said:
probably, but it will come with a weight penalty. The same power rated genset will turn 1500 vs 1800 rpm, requiring more torque. 50Hz transformers are marginally heaver than 60Hz only. BUT, knowing what I know about your next boat, weight of the electrics will be negligible :D
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diver dave said:
probably, but it will come with a weight penalty. The same power rated genset will turn 1500 vs 1800 rpm, requiring more torque. 50Hz transformers are marginally heaver than 60Hz only. BUT, knowing what I know about your next boat, weight of the electrics will be negligible :D
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I can't speak for all MFG. But cats do not need to be bigger unit to run 50hz. We have rental unit that can be set for 50 or 60 Hz operation. Only changes are to the rating number in the ecm and setting's in the avr and genset control. Some of the biggers unit you have to change the turbo hot housing and fuel setting's. But I haven't seen anyone derate the kw when changing the Hz from 50 to 60 or the other way.
 
Add North Pacific to the list of builders making fiberglass tanks for fuel, water and holding.

Rob
 
Anyone ever priced tanks in monel vs mild steel?
Isn`t f/g good for original build but less practical as a replacement.
For a replacement, properly built and installed and protected mild steel could outlive the boat.
 
BIG CAT said:
I can't speak for all MFG. But cats do not need to be bigger unit to run 50hz. We have rental unit that can be set for 50 or 60 Hz operation. Only changes are to the rating number in the ecm and setting's in the avr and genset control. Some of the biggers unit you have to change the turbo hot housing and fuel setting's. But I haven't seen anyone derate the kw when changing the Hz from 50 to 60 or the other way.
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Look at the cat C16. For both 50 and 60. Appears almost a 10% hit on kW.
On a field changeable unit, cat may just default to the 50 hz rating. Maybe?
 
Have been doing some hot metal spraying lately. A mild steel tank, abrasive blasted on the outside, metal sprayed with zinc and then epoxied should never corrode from the outside.
 
FF said:
...

One advantage of a custom tank is the ability to have a proper fill tube and sump built in.

This means no "fuel polishing" forever and the ability to handle a bad fuel load that contains 1/2 water.

....
Click to expand...

Can you explain how this works?
It's not obvious to me.:confused:
 
makobuilders said:
I know that a sump is the accepted means of building a tank, able to trap a cup of water or so. But I've always thought that a better way to build a tank would be with the fuel pickup reaching all the way to the bottom. Constantly drawing any dirt or water, which gets filtered out in the Racor. Basically constantly polishing the fuel, like what my old Jimmies did.
Click to expand...

The KK42 fuel feed is about two inches from the lowest point in the tank. In an absolutely still boat, this will leave about 7 to 10 gallons below the feed.
Which in my experience is about the prefect amount. With normal boat movement, some of it will get fed and therefore filtered, but the last couple gallons pretty much don't.

I also like your idea about 220v.
 
We had a custom 565 gallon fiberglass tank built for a previous boat. They had to cut out the deck and bulkhead in the cockpit and aft cabin to get it in. We had the pickup tube go down to about 1/4” off the low point of the tank. The tank was shaped to follow the slope of the hull because we wanted the maximum capacity possible. With the pickup that low it would suck any water or debris out of the yank and into the Racors where we could empty it out. I didn’t want any water remaining in the tank.
 
I didn't know you could buy metalizing guns still. That's fantastic. It would be a dream to flame spray the entire exterior of a steel boat.
 
Can you explain how this works?
It's not obvious to me.:confused:

The fuel tank is constructed so the deck fill with a 3 0r 4 inch cover is directly above tank & the sump.

Think of the sump shaped as an old style oil filter cover , say a foot long and 4 inches in diameter

The sump is connected to the top of the tank by a fixed fill pipe with numerous holes .

A screen pipe with fairly fine mesh is inserted from the deck fill to the bottom of the sump., thru the fixed pipe with holes .

At the screen bottom is a cup that fits the sump fairly tight.

With a bail on the screen pipe it can be lifted out of the fill pipe.

This allows the screen to be cleaned of fuel debris , and the cup on the bottom of the screen pipe can bail the sump , over and over if there is much water.. An o'nite wait may be required to get all the water to sink.

Finally when all the water is bailed , the only remaining water will be inside the sump where the small quantity should only create a small amount of bug waste for the filters to deal with.

The US Navy used this fill system on many of their wooden boats , and Palmer Johnson used it on loads of their vessels .
 
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Comodave said:
We had a custom 565 gallon fiberglass tank built for a previous boat. They had to cut out the deck and bulkhead in the cockpit and aft cabin to get it in. We had the pickup tube go down to about 1/4” off the low point of the tank. The tank was shaped to follow the slope of the hull because we wanted the maximum capacity possible. With the pickup that low it would suck any water or debris out of the yank and into the Racors where we could empty it out. I didn’t want any water remaining in the tank.
Click to expand...

I'm curious, who built the custom FRP tank?

Given the choice I believe FRP is the ultimate choice for all tanks, not just fuel. Using the right materials they can be expected to last indefinitely. I've accessed and cleaned FRP tanks on 40 year old Hatteras models and they were as good as new afterward, not something you can say about most metallic tanks. And, they can rest directly on the hull or even in bilge water with no ill effects, again something you can't do with metal.

Today a number of builders use FRP for tanks, all tanks on all new Nordhavns save the supply tank are FRP, fuel, water and waste. Fleming also uses FRP for tanks, with a built in well for water and sediment removal. Both builders meet flame retardant standards using a coating. They are more expensive to build, but for those who build boats not much, and builders who use them are pretty much assured of never having a failure.
 
Steve DAntonio said:
Given the choice I believe FRP is the ultimate choice for all tanks, not just fuel.
Click to expand...

FRP is good for diesel fuel. And many other liquids.

For gasoline not so much. With the use of alcohol in gasoline FRP fuel tanks have experienced degrading issues.

The issue with recreational boat tanks is the vessel is recreational. Usually meaning less usage than say commercial. If fuel (and other fluids) were being moved through the tank on a daily/weekly basis many of the internal issues of a tank would go away. Nothing stays in the tank long enough to become an issue. Small amounts of debris and water move in and move out such that there is no longer an accumulation of the unwanted stuff.
 
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Steve DAntonio said:
I'm curious, who built the custom FRP tank?

Given the choice I believe FRP is the ultimate choice for all tanks, not just fuel. Using the right materials they can be expected to last indefinitely. I've accessed and cleaned FRP tanks on 40 year old Hatteras models and they were as good as new afterward, not something you can say about most metallic tanks. And, they can rest directly on the hull or even in bilge water with no ill effects, again something you can't do with metal.

Today a number of builders use FRP for tanks, all tanks on all new Nordhavns save the supply tank are FRP, fuel, water and waste. Fleming also uses FRP for tanks, with a built in well for water and sediment removal. Both builders meet flame retardant standards using a coating. They are more expensive to build, but for those who build boats not much, and builders who use them are pretty much assured of never having a failure.
Click to expand...

It was in San Diego, I don’t remember the companies name since it has been about 20 years ago. It was a beautiful tank...
 
Steve DAntonio said:
I'm curious, who built the custom FRP tank?

Given the choice I believe FRP is the ultimate choice for all tanks, not just fuel. Using the right materials they can be expected to last indefinitely. I've accessed and cleaned FRP tanks on 40 year old Hatteras models and they were as good as new afterward, not something you can say about most metallic tanks. And, they can rest directly on the hull or even in bilge water with no ill effects, again something you can't do with metal.

Today a number of builders use FRP for tanks, all tanks on all new Nordhavns save the supply tank are FRP, fuel, water and waste. Fleming also uses FRP for tanks, with a built in well for water and sediment removal. Both builders meet flame retardant standards using a coating. They are more expensive to build, but for those who build boats not much, and builders who use them are pretty much assured of never having a failure.
Click to expand...


I know somebody is building FRP tanks in Port Townsend, saw a pair under construction and they looked great.
HOLLYWOOD
 
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