fuel tanks-revisited...

[jawz12]

we gonna do a revisit on fuel tanks here...someone sent me an email stating the info i gave concerning aluminum fuel tanks is wrong,an aluminum fuel tank will protect itself,and it doesn't need to be coated in anything-it's a waste of money...interesting huh ???
well...here's a fuel tank i recently removed...it's completley unprotected,it's in a boat with a fully encapsulated deck-there's no tank access what so ever...

check it out...and let me know what you think...everyone with an older boat should take note of these pictures...remember,if the than looks ok on the top,that doesn't mean it's ok on the bottom or the sides...


and "yes" this is the same tank...it's approx 15yrs old...some of these erosions were almost through the tank,it wasn't gonna hold up much longer...

[gottaflylee]

Jimmy, another great point you have here for another great thread. NOw when you say "fully encapsulated deck-there's no tank access what so ever" does that mean that the tank is surounded by foam or does that mean that you can't get the tank out with out cutting out the deck...thanks...

[Questsportfishing]

My hats off to you for being man enough to point out stuff to people and stand your ground! After doing these bertram tanks (5 to date) and seeing the result of todays fuel eating fiberglass resign right out of the lay-up people should not want even a drop of e-10 hitting the deck. I still like the interlux 2000 to coat the tank before I drop them in I guess coal tar epoxy or even awlgrip prime n paint is great just as long as it's coated (and twice on the bottom up 1'2 way!) a tank now days will run you in the neighborhood of 9-15 bucks a gallon... take it out and replace it ... a lot more! I am seeing the new fuel eat into the old tank fuel / varnish layers also...makes ya cross your eyes some! I seen also that 100 gallons of ethanol can make 1 gallon of water in 6 months.. thats scary! I sure would like to see a ruling where we can get tanks with a bottom drain fitting installed to get the nasty stuff out.

[perfectscore]

if i were puttin in a new trank i would coat it with everything i had. I had a tank that corroded from the outside in vs. inside out. the inside looked purty as anything but it is eat its way thru. why take the chance to have to cut, remove all kinds of sheet to get to the tanks, coat'em up

[fishduck]

I have replaced a few tanks. It's true alum tanks corrode from the outside in. Most manufactures foam in tanks, the foam holds water and it eats through the tank. That's why the Coast Gaurd has made it illegal to use stainless steel for fuel tanks. Stainless tanks corrode from the inside where the damage cannot be seen by inspectors.

Michael

[fishduck]

By the way the last tank I installed I did coat with a interlux primer for aluminum thinking the paint would help keep the water off the aluminum. I just sold the boat so I don't know if it helped.

Michael

[ElMar2530]

Nice post Jaws!!

What do you think of the Coal Tar Epoxy alot of guys are putting on aluminum tanks before the install??

I will have to replace the tank in my 20 Seacraft soon and agree that the cost of coating it is negligable compare to the job and what you get in the end.

Was thinking of going with Coal Tar but never used it before.

[Questsportfishing]

get everything dry fitted and make sure everything fits and tank structure is finished and tank is ok to go in. set up everything you need and a cpl extra sets of gloves. Do not make a mess. the stuff protects the metal from water. I know some dont like it but I foam in my tanks on some boats. others get straps and wedges. make sure you dont ever have to touch it for twenty years.

[jawz12]

Nice post Jaws!!

What do you think of the Coal Tar Epoxy alot of guys are putting on aluminum tanks before the install??

I will have to replace the tank in my 20 Seacraft soon and agree that the cost of coating it is negligable compare to the job and what you get in the end.

Was thinking of going with Coal Tar but never used it before.

only way i do fuel tanks is like this...

i first scuff sand the surface and then clean it in acetone...then the surface gets chemically etch primed-the chemical etch prime is real important,without first etch priming an aluminum surface,the coating will not have a good adhesion-meaning,it's probably gonna pop off...
after the chemical etch prime,i coat the entire surfqace with interprotect 2000e-same epoxy i use for hulls.this is a completley water proof epoxy barrier coat.doing this process in the correct manner,the tank will be completley protected from any moisture-the aluinum surface is completley isolated...i've never used coal tar,so,i can't comment,i use what works for me...

[kingpin]

I would not scuff it up and break that bond on any new gas tank.


I would never refurbish older aluminum tanks. If you've gone through the work of removing the tank, any corrosion found is good enough reason to pitch it, even what appears to be surface corrosion, it just isn`t worth the time.

I wouldn`t believe the exterior on new tanks would be untreated.

IMO I would ask the manufacturer to what chemical was used.

On new tanks the surfaces are most likely is chromic etched after welding.
Its probably bathed in acid inside and out and had a water rinse.

Alodine for example is a chromic acid made by Parker Amchem.

If you use an alodine (carcinogenic,) treatment follow the directions, some are use and dry others have a thorough water rinse to stop the acid from further etching.

I don`t know all the regulations on concealed fuel tanks and covering those surfaces so I`ll stop there to protect myself.

For aluminum protection in general... after the chromic acid you could use a zinc chromate (another carcinogen) primer, and then paint with a suitable layers of paint to protect the primer.