Leaking Fuel tank

Corrosion, Paint, Through Hulls, etc.
wschneid
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Leaking Fuel tank

Post by wschneid »

I have a 1986 31 ft. flybridge sedan. I have a leaking fuel tank. Does anyone have any experience with removing, repairing/replacing a fuel tank? My boat has two 75 gal. tanks. Only one seems to be leaking with a few pinholes.

William Schneider
jralbert
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Re: Leaking Fuel tank

Post by jralbert »

Bill: Just a thought. When you tackle the problem, be mindful of the possibility that whatever is affecting one tank is likely to be affecting the other. Replacing both may be in order. Hope you can pinpoint the locations of the leaks
-joel-
former owner 1988 '32 FB Sedan
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twin 318 / 240 hp
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Fastjeff
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Re: Leaking Fuel tank

Post by Fastjeff »

Good advise!

Hate to say it, but they both have to come out 'cause you don't want to fool around with potential gas leaks! And don't let anyone talk you into using aircraft sealing compound to fix the problem: That stuff is like Russian Roulette with 5 bullets in your old six gun--IF all goes well, the tank will be fine, but...

Good luck!

Jeff

PS: Have you considered going to one, semi large center tank? Might be easier in the long run. Many big Ms came that way.
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
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Busia
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Re: Leaking Fuel tank

Post by Busia »

New tank put in through the rear hatch.
NEW GAS TANK.jpg
BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW
wschneid
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Re: Leaking Fuel tank

Post by wschneid »

Thank you guys for the info.

Bill Schneide
wschneid
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Re: Leaking Fuel tank

Post by wschneid »

Busia,
In your photo It looks like you are using one tank, placed across the boat. Am I right? Secondly, what did you do to remove the old tanks?

Bill Schneieder
TinLizzy
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Re: Leaking Fuel tank

Post by TinLizzy »

The older models had one tank like Busia's, and the exhaust ran on the side of the hull. Newer models had 2 smaller 75 gallon tanks on the side of the hull and ran the exhaust in between the tanks and had a 45 degree elbow before it exited the hull. If you go to a one tank system, you will have to account for the exhaust changes. I removed my 75 gallon tanks through the rear hatch after draining all the fuel out, removed all the hold down brackets, and removing the exhaust. There was not much room, but they did make it out of the hatch. I myself would go back with the two separate tanks. Get the dimensions and decide if you are going to go with aluminum or poly, then google them and get the closest size you can that will still fit through the hatch. Great Lakes Skipper had quite a few different options the last I looked. Good luck!
Rodney
1975 28 Express-Twin 350 Chevy's, SOLD
1990 32 Express-Twin 360's
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Busia
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Re: Leaking Fuel tank

Post by Busia »

wschneid wrote: Mon May 16, 2022 5:08 am Busia,
In your photo It looks like you are using one tank, placed across the boat. Am I right? Secondly, what did you do to remove the old tanks?

Bill Schneieder


Yes, I had one tank. I had a new one built out of 3/16" aluminum, larger than the original. I removed a couple of braces for the floor to make the opening as large as possible and had the tank made just a bit smaller. I would never go with a plastic tank for gasoline as they will build up a static charge and discharge with a spark. They do make some plastic with added carbon that will conduct electricity and can be grounded.
I put 350 Crusader engines in mine, with 4" exhaust so I could not slide the tank as far forward as before. If you get a tank made, make sure they weld a tab on it so you can connect a ground wire to ground the tank. I also added a port on the top corner with a plug in it. Every spring I heel the boat over so that corner is the low point, pull the plug and stick a 1/4" copper tube through the port to the bottom of the tank. I can then pump the bottom of the tank out and check for water on the bottom. I have found that even if they don't tell you that the gas has alcohol in it, it does. Lots of alcohol in it. It will absorb the water and cause many problems.
To remove the old tanks, just pump them out, disconnect any lines and remove them out the rear hatch.
BIG SECRET ! If you have a gas gauge right on the top of the tank, it is the same as a gauge on a propane tank. You might have seen them on a propane-powered forklift. My propane dealer had parts right on the shelf, and cheap too.
BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW
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Busia
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Re: Leaking Fuel tank

Post by Busia »

I will try to show some pictures from my phone here. They are what I pumped off the bottom of my fuel tank. The gas looks blue from an additive to help with the alcohol in the gas. I will drain the tank and start the summer with new gas.
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BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW
Fastjeff
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Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Leaking Fuel tank

Post by Fastjeff »

That looks like the dreaded Whote Gook that is created by ethanol gas and cannot be burned by any known additive. It's also corrosive.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
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