Fuel tank replacement job

Yep, been there done that ! I refitted with S/steel, carefully welded in place WITH a sump drain sludge/water drain. Don't even mention the price but I reckon Stainless is Painless.

Hey ! S'cuse me guys the jobs crappy enough without mentioning 'Wheated Bourbon' HUH ! try 10 year old Bushmills Irish Whiskey and don't even think about contaminating it with ice cubes or water.
Jeez the very thought would make a grown man cry.

Irish Rambler said:

Hey ! S'cuse me guys the jobs crappy enough without mentioning 'Wheated Bourbon' HUH ! try 10 year old Bushmills Irish Whiskey and don't even think about contaminating it with ice cubes or water.
Jeez the very thought would make a grown man cry.

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Sorry but I have a taste for the Wheats. I may try your Bushmills it sounds good by the review.
BTW why does Irish whiskey need American Oak barrels to age. Don't you have white oaks across the pond?

Triple M Plastic products will custom weld plastic tanks.

Is welded plastic legal for fuel tanks?

I was under the impression that fuel tanks must be linear PU, which is difficult or impossible to weld. You normally see these rotomolded. Non-linear PU can be welded for water and waste tanks.

A read through the ABYC standard H-33 (diesel fuel systems) says that non-metallic tanks such as fiberglass can be used but must pass the same tests as other materials. No specific reference or exclusion of plastic. Manufacturer claims their tanks meet minimum USCG Standards:

Triple 'M' Plastics » Custom Fabrication

DDW said:

Is welded plastic legal for fuel tanks?

I was under the impression that fuel tanks must be linear PU, which is difficult or impossible to weld. You normally see these rotomolded. Non-linear PU can be welded for water and waste tanks.

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Does anyone have plastic tanks in their boat? I have read a lot of threads on TF that mention the use of replacement poly tanks, but I have not found anyone who has done it.

Here is a blog of my fuel tank replacement photos if it helps.

Saving Tortuga: Fuel Tank Removal and Replacement

Greatlaker221 said:

Here is a blog of my fuel tank replacement photos if it helps.

Saving Tortuga: Fuel Tank Removal and Replacement

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Thanks, I have studied your great blog several times. Thanks for sharing.

Er Fridaze, they actually use barrels from Portugal.
C'mon give our exports a boost and buy some 10 yr. old Black Bush, or even some Millennium, when you've tried Black you won't go back and i'm talking strictly whiskey here.
Like any drink its a matter of personal choice but try a wee drop any way, you will enjoy it, the wheat is Irish grown and the water is from a local spring.
During the prohibition they kept making whiskey and so it matured until prohibition was lifted. America's Kennedy family were keen to smuggle it via Canada.
Bushmills is the oldest licensed whiskey distillery in the world

https://www.powerandmotoryacht.com/.amp/maintenance/tips-on-replacing-the-fuel-tanks-on-your-boat
Interesting read on fuel tank materials. I think it's to early for me to try plastic tanks. They do sound promising.

Any reason you chose aluminum over steel? Lucky to get 15 years out of aluminum tanks. I had to replace 4 of them on a previous boat. Gasoline doesn’t have the sludge of diesel to help corrode from the inside.

kapnd said:

Looks like (photo#5) there was actually a low point drain fitting right behind the pickup/return lines, was there a valve installed there?
If so, it’s use could have saved your tanks.
Thanks for the photos, a grim reminder that tanks need regular maintenance.

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No the low point drain had a plug in it with no valve. I drained all but the last gallon thought through a Racor 900 and saw no water in the bowl. After sucking out the last gallon I let it settle and saw no water. I probably transferred almost 80 gallons. It makes no sense to me. All that rust indicates water. Maybe it goes into the sludge.

High Wire said:

Any reason you chose aluminum over steel? Lucky to get 15 years out of aluminum tanks. I had to replace 4 of them on a previous boat. Gasoline doesn’t have the sludge of diesel to help corrode from the inside.

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The tank fabricators I have researched use Aluminium. I assume when you say steel you mean stainless. SS and AL are susceptible to crevise corrosion. What is the bases for you 15 year expiration on AL?

I think aluminum is the tank material of choice now. I would gladly pay for a thicker than minimum gauge of aluminum. It will take longer to corrode through. I would install it properly with bonded strapping on the bottom, top and sides. I would make sure that the deck fills are caulked properly. Having a low point if possible and make that low point the fuel pickup so that any water would get sucked out and filtered out with the engine running. I would get rid of the insulation that surrounds my current tanks so I could inspect the tanks and would also have inspection ports into each baffeled area of the tanks. I think that would make the most reliable tank you could get except for a plastic custom manufactured tank and I am not sure that there are any made in the US now. I saw a thread about a company in the UK that is making tanks like that but I don’t know how you would go about getting one sent here. Also don’t know if they meet current ABYC guidelines.

Dang, Dave...this is painful watching you do this. How could a boat in such great condition have all that sludge inside?! Anyway, thanks for blogging it right here on TF. My 30 year old stainless tanks are going to go the same route one day. Glad I’ve got you to call when it happens!

The good thing about replacing the fuel tanks is that by the time they will need replacement again I will be dead and it will be someone’s else's problem.

healhustler said:

Dang, Dave...this is painful watching you do this. How could a boat in such great condition have all that sludge inside?! Anyway, thanks for blogging it right here on TF. My 30 year old stainless tanks are going to go the same route one day. Glad I’ve got you to call when it happens!

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No pain no gain Larry! Other than the beating I gave my body the one day this is no hardship. I love working boats. There is a great deal of satifaction. I will be able to dress up half the ER due to all the access to thing outboard. I can't wait to get back to it next week. All the folks here on TF have validate my plans or given me additional items to address.

Been there , done that. You are doing the right thing by doing it yourself. No one wanted my job ,had crazy ideas and prices were stupid crazy. Used A Frame to rise complete engine over other to get space to install tank and Also cut mine out . Good luck and it will be one of your better boat projects.

Nothing that a gallon of Bilge Kote won’t fix. I would really like to be able to get to mine and clean it up and paint it nice and white.

High Wire said:

Any reason you chose aluminum over steel? Lucky to get 15 years out of aluminum tanks. I had to replace 4 of them on a previous boat. Gasoline doesn’t have the sludge of diesel to help corrode from the inside.

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Frydaze, Nice write up for a nasty job.


Highwire , I,ll guess something was done incorrectly on yours, poor technique, wrong grade????
I have aluminum tanks, now about 35 yrs old and no sign of trouble. Maybe tomorrow but hope not.
They are bottom feeders so any crap heads for the filters so does not accumulate.
Wasn't,t my doing but original owner, I just benefitted from his foresight.

My experience from my 1986 Phoenix 29 was outright scary. In 2000 my two 80 gallon aluminum main tanks were corroded badly. The ground connection tabs completely disintegrated. The outside surface was covered in powdery aluminum oxide. I also had two saddle tanks that looked new and a center line tank that looked new but completely obstructed access to vital things like shaft packings, seacocks and such. I decided to replace the mains and all of the fuel hoses. The saddle tanks needed to come out first before the mains. Long story short the perfect looking saddle tanks had holes in the bottom that a pencil would fit though under the glued on neoprene strips installed by Phoenix when constructed. The aluminum transformed into a gray tooth paste looking substance on the bottoms of all of the tanks. All five tanks contained gasoline prior to the replacement job and never indicated any leakage. The thoughts of water and sludge common in an aluminum diesel fuel tank is a no-go for me. Good luck.

High Wire said:

My experience from my 1986 Phoenix 29 was outright scary. In 2000 my two 80 gallon aluminum main tanks were corroded badly.

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With all do respect, the technology, alloys, and fabrication techniques have changed in the last 32 years.

Ted

Since jet fuel is essentially refined diesel and most aviation tanks are made from riveted parts covered in sealant, why not use Pro-seal 890 or 1422 to fix leaky metal tanks on boats? An awful lot of airliners and military planes are flying around with wet wings and no leaks.

Woodland Hills said:

Since jet fuel is essentially refined diesel and most aviation tanks are made from riveted parts covered in sealant, why not use Pro-seal 890 or 1422 to fix leaky metal tanks on boats? An awful lot of airliners and military planes are flying around with wet wings and no leaks.

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I considered going the sealant route. My tanks design wouldn't support it. The two baffles would require installation of large manways in the three compartments. Even if it had manways the prep work with the rust would have been worse than the cut up. I didn't find the leak until the tank was out. It was at a bottom weld crack sitting on a support. I could have welded the small crack if it would have been 3 inches left of right. But then I would still have a 30 year rusty tank with a lot of sludge that can't be cleaned out.

A lot of the trouble is having metal tanks supported by their plating on large areas with no ventilation. If you have new tanks made, have them weld a U channel to the bottom anywhere they sit on something. That interface tends to get wet and stay that way, and corrodes. If it is corroding the U channel rather than the tank plating it does little harm for a long time. The U channel can be made much thicker than the tank plating as well.

Plastic tanks don't corrode, but they can crack. I had a rotomolded waste tank in a boat that cracked from stress. They must be very carefully supported to prevent this.

DDW said:

A lot of the trouble is having metal tanks supported by their plating on large areas with no ventilation. If you have new tanks made, have them weld a U channel to the bottom anywhere they sit on something. That interface tends to get wet and stay that way, and corrodes. If it is corroding the U channel rather than the tank plating it does little harm for a long time. The U channel can be made much thicker than the tank plating as well.

Plastic tanks don't corrode, but they can crack. I had a rotomolded waste tank in a boat that cracked from stress. They must be very carefully supported to prevent this.

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To address the area where the tanks sits on the supports I plan to glue plastic to the tanks with 5200. The aluminium will not be in contact with any surface.

Dave:

Hope your sore muscles are better today!

Are those rubber strips that are nailed over the transverse ribs, or a tar-paper type of material? Are the ribs still solid? They look well glassed in.

We will soon be building and glassing in some ribs to support our aluminum tanks, so this is a great thread to observe.

Thank you,
Pea

Miz Trom said:

Dave:

Hope your sore muscles are better today!

Are those rubber strips that are nailed over the transverse ribs, or a tar-paper type of material? Are the ribs still solid? They look well glassed in.

We will soon be building and glassing in some ribs to support our aluminum tanks, so this is a great thread to observe.

Thank you,
Pea

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Almost healed up. The rib supports are covered in some kind of rubber. It is in very good condition. The rib supports are glasses into the hull. Supports are solid and in good shape.

Hello Fryedaze,,Jack & Judy aboard "Regalita" Just wanting to say Hi,and will watch your progress on tank replacement.Take care Jack

Thank you!

Great post keep it coming!

Aloha!
Joe