1986 Outrage 18 Fuel Tank: Need For Replacement

[Palomino]

I have a 1986 Outrage 18.

After reading many posts about the original 63-gallon aluminum fuel tank, I [have been thinking about] replacing the fuel tank while I will be installing a new engine and re-wiring the boat, as the deck will be removed, and at a later time after all the new controls are installed, the work would be more difficult.

The dilemma is the original fuel tank is fine. I have weighted the boat and determined the hull is holding zero water. I visually see zero evidence of any moisture intrusion, ever. I cannot see any evidence whatsoever of corrosion in the tank or on the exposed surface of the tank. It is foamed in tightly, there is no wiggle room.

Q1: should I replace the fuel tank on my 1986 OUTRAGE 18?

[Rhetorical question ]where does the [notion] come from that the fuel tank is 38-years-old and needs replacing?

I [habitually] read [in unspecified sources] an aluminum fuel tank has a lifespan of 20 to 30 years or so, and I just don't get it.

If [an aluminum fuel tank is] encased in foam and [has] no corrosion, the welds do not seem like they would give out; they are encased in foam.

Q2: [what something] am I missing [that necessitates replacement of a fuel tank at age 20 to 30-years-old]?

I am leaning towards replacing [the fuel tank] "just because."

Q3: am I fixing a problem that doesn't exist?

[pagraham]

I recommend you replace the fuel tank on your OUTRAGE 18.

I had an [writes "eighty-nine feet" using an apostrophe in the wrong place where he should have written 1989] Outrage 18 that exhibited an odor of gasoline; I replaced the fuel tank.

I now have a [1987 ALWAYS USE FOUR DIGITS FOR YEAR] Outrage 20, Because the cockpit deck was soft and needed to be redone, I replaced the tank. There was not odor of gasoline, but I removed the fuel tank for inspection. There were signs of corrosion and pin holes on the fuel tank side wall, even as the top of the fuel tank looked fine.

[The original fuel tank was] pressure tested [but no report of the outcome of the pressure test was mentioned].

[Palomino]

Thanks for your comments.

I believe I will pull out the fuel tank just for my own peace of mind.

I will follow up in this thread with the a report on the condition of the fuel tank.

[jimh]

The condition of an aluminum fuel tank in a c.1986 Boston Whaler hull depends entirely on the prior use of the boat, the care it was given, and the environment in which it was operated. The notion that all aluminum fuel tanks have an end of their service life at age 20-years is silly.

The rubber hoses, particularly the large diameter fuel fill hoses, are MUCH more likely to decay and become a source of leaking gasoline than the aluminum fuel tank.

If there is an odor of gasoline present in the fuel tank area, the source is more likely to be from a low spot in the fuel fill hose as it comes across from the gunwale to the tank. Fuel left sitting in that low spot will begin to permeate the rubber hose and eventually leak through the hose.

If you are going to remove the section of the deck that covers the fuel tank cavity, I would focus your restoration efforts on replacing the the rubber fuel fill hose all the way from the fuel fill inlet fitting to the elbow on the fuel tank. Also inspect the vent hose and the fuel delivery lines.

As for pressure testing the fuel tank, a pressure test can be done while the fuel tank is still in place in the hull. There is no need to remove the fuel tank to perform a pressure test. Be CERTAIN to observe the limit of the pressure used in the test. The original fuel tank level should specify the maximum allowed test pressure, which will typically be very low, perhaps 2-PSI. Too much pressure in the test can cause a problem where none existed before the test.

[Phil T]

Do a pressure test in situ. 3 psi.

Replace the fuel fill, vent and supply with alcohol resistant marine fuel line.

[Palomino]

I pulled out the fuel tank.

I found there was not any corrosion [in the fuel tank].

[There is a 50-percent chance I will re-install the original fuel tank] and foam it in place as it was originally.

I may prefer [to have a new and] smaller [fuel] tank [custom fabricated so that there will be] about four-inches of room in the [fuel tank cavity] to install a sump pump.

The deck [perhaps is now talking about the removed portion of the deck that covers the area of the fuel tank cavity] had no soft spots. There was some dry-rot along the edges and also extending up into the center [again, may be talking about the removable molded deck that covers the fuel tank cavity which has a large plywood sheet bonded to the laminate to reinforce the deck]. The resin is cracked in several areas. I will attempt a repair.

I may replace the deck with PVC [sheet], as it will be lighter and it will never rot.

I removed the fuel tank by myself. I used a 4200-PSI pressure washer with a turbo nozzle tip to blast out the foam. The amount of work involved was decent. Initially I did not think I was going to be able to remove the fuel tank, but I continued the process just to remove the foam surrounding the fuel tank. At some point I stepped on the fuel tank and noticed it was floating.

The fuel tank is not heavy.

I watched [several] video presentations that stated installing a fuel tank is a two-person job, but now I don't see why that would be true

[jimh]

Q3: am I fixing a problem that doesn't exist?

I believe you have now answered your own question in the affirmative.

I may replace the deck with PVC [sheet], as it will be lighter and it will never rot.

I do not think PVC sheet would be a better material to use for the deck covering to replace the laminated original deck. And if you meant that you would retain the original laminated deck but replace the wood reinforcement material with PVC, I am not sure that PVC sheet will be lighter or stronger than the original plywood. Marine plywood adhered to the laminated deck with epoxy resin and properly sealed will not rot.