Fuel tank Question

[Monterey10]

* I've misplaced the name of the company that sells marine fuel tanks. I beleive the company was in Los Angeles.* They were unique in that they sold several thin tanks that stacked up where the original tank was.* The thin (stackable) tanks were the correct size to slide down past the engine. (saving you from removing the engine)** The tanks were tied together with fuel lines.

*Any comment on how well these worked as compared to a fuel bladder inside the original fuel tank?*

*Thanks for your time..

-- Edited by Monterey10 on Sunday 29th of November 2009 12:41:56 PM

-- Edited by Monterey10 on Sunday 29th of November 2009 12:42:36 PM

 

[Enola B]

That sounds interesting, I may be in the market for new tanks as well. My 1975 Marine Trader still has it's original steel tanks. Not leaking but tops are very rusty.
Ill watch this post and hopefully sombody will remember who they were.
Bill

 

[Monterey10]

* I'm pretty iritated with it.* I had all this written down somewhere and have lost track of the info.*** I'll keep searching.

 

[FF]

"Any tank builder can make smaller tanks to your specifications. Just figure out what size you can get into your tank space and get a few builders to quote."

However a good fuel tank DESIGN can be copies that solves the water in the tank hassles.

Self maintaining (well almost) but at least the nonsense of "fuel polishing" can be avoided .

Another possibility is a custom bladder , that drops into the shell of the origional tank.

 

[Marin]

The previous owner of our boat had the original iron tanks replaced. The boat was built with three 150 gallon tanks, two saddle tanks at the aft end of the engine room and a tank that ran across the back of the engine room. They were replaced with four 85-gallon "cubes"--- two side by side on each side of the engine room where the saddle tanks had been and a fifth tank--- a 60 gallon day tank--- on the centerline of the boat under the engine room floorboards. All of these tanks can be removed without interference from the engine although the shafts would have to be disconnected and slid back. I don't know if the transmissions would have to be removed. The total fuel capacity of the boat was reduced from 450 gallons to 400 gallons but that is not a problem for the way we use the boat. Actually it's a benefit because we go through the fuel faster so it doesn't sit around as long.

The tanks are made of stainless which is not an ABYC-approved material for fuel tanks, and we would not have used stainless if we'd had the new tanks made. But they were on the boat so we'll use them until they fail. They are very well made, however, so hopefully they will last for a decent period of time before needing replacement. The four saddle tanks drain by gravity into the day tank, so no water can accumulate in them. The saddle tanks each have their own sight gauges, the day tank has a level gauge at the helm. The engines and generator normally feed from the day tank but the system can be valved to feed any engine from any tank.

-- Edited by Marin on Monday 30th of November 2009 12:16:01 PM

 

[RickB]

Marin wrote:The tanks are made of stainless which is not an ABYC-approved material for fuel tanks, and we would not have used stainless if we'd had the new tanks made.

ABYC standards list stainless steel in grades 316L and 317L as meeting*requirements for corrosion resistance*of materials used in the construction of gasoline or diesel fuel tanks.

In other words, SS is approved by ABYC for fuel tanks.

*

 

[Marin]

I was going by what the survyor said who did the buyer's survey on the boat in Alameda where we bought it. He said stainless was not approved by the ABYC and cited this on the survey, although he added the caveat that he'd seen many boats in the SFO area that had stainless tanks and most of them were holding up fine. This was in 1998 so perhaps this was the position of the ABYC at the time and they have since changed their position.

The surveyor told me stainless was not approved (at least not at the time)*for two basic reasons.* One, the quality of stainless can vary all over the map depending on who makes it.* Just because it's labeled "316" does not guarantee that it will have the desired properties, particuarly if the steel was made in Taiwan, China, etc.* Two, he explained how welding alters the property of stainless, and if not done correctly can lead to corrosion problems and leaks*developing along the weld lines.* He told us it was because of the variable nature of stainless construction that the ABYC did not consider stainless steel a satisfactory material to fabricate fuel tanks with.

In conversations with people I have met over the ensuing years in the marine engine and fuel tank fabrication business I have heard the same explanations as to why stainless is a less-than-ideal material to use for fuel tanks.* So based on this input I would not recommend stainless as a good fuel tank material even though our boat has it.* There are apparently*too many variables to be fully confident with it.

-- Edited by Marin on Monday 30th of November 2009 06:41:40 PM

 

[melkowal]

I had the fuel tanks replaced in our 1983 Grand Banks twin diesel Motoryacht model with aluminum tanks by American Tank. See: http://picasaweb.google.com/melkowal/FuelTanks02# for photos. Three tanks side by side replaced one. Capacity reduced from 300 gallons per side to about 250 gallons per side. Vince did a great job.