Replacing fuel tank - alum. or plastic?

[bearclaw]

It's way past time to do this to my 20-yr.-old Viper. I bought the base boat new and stuck a permanent Tempo 12-gal. steel tank in the back. Now 20 years later, there's some rust at the cap so I'm betting the tank is pretty gnarly. I'm replacing lines/elec. pump/regulator, etc., but what kind of tank to use?
I did a search but I can't really see a consensus.

oh, and lines: is the primer bulb/fuel line Mercury sells okay?

Tanks :D,
Barry

[flabum1017]

Your choice really...... aluminum will eventually corrode in a salt water enviroment but will last a good long time in fresh water............... Plastic tanks will deform in the heat and who knows what will happen to them as other chemicals are added to fuels in the future...... It's bad enough with the ethanol added and getting worse. (Thanks to our Dems)

As for fuel lines..... OEM is good, but there are other choices out there such as Sheilds hose and others.

[Jeff_G]

I prefer the new poly tanks myself. Lightweight and not affected by anything in the fuels today. Aluminum is good and once was the choice but it does corrode and can split. If you chose poly keep it out of direct sunlight for longevity.

As for fuel lines and primer bulbs i really don't know. I had recommended Quicksilver exclusively as I never has a problem with them. Recently I have had 2 returned. Mercury bought Attwood a couple years ago. The new Quicksilver, even in Quicksilver boxes look like the Attwood, they no longer have the Quicksilver name on the bulb nor the part number, just plain jane, so I don't know.

[Rigaud]

I just took out a poly tank from my rib boat which has been in it since 1998 in direct sunlight. It doesn't get hot like down south but we do get some summers in the 90's F and it hasn't deformed at all. The top has discolored a little and I did replace o-rings plus seal but otherwise it's fine.

I'm in the process of building a boat with internal tanks which wont be in any light but I'm not certain myself what to put in that one and I'm in fresh water.

[T-REX]

Aluminum is good and once was the choice but it does corrode and can split.

I'm wit Jeff......I have had good luck wit tha plastik tanks.......Have had more than one aluminium tanks crack, or split in tha seems.....

Quess it all depends on what kinna water ya run in.,.,.,If it's aways smooth, and don't hit waves or have any vibrations, aluminium will be fine!!....JMO

[Maritime_Eng]

Look for a good XLPE (Cross-linked polyethylene) Tank. They are very strong and will not deform like other plastic tanks. Stay away from LLDPE or MDPE becasue they will absorb fuel and expand.

[Markus]

Polyethylene is the material of choice for fuel tanks for marine as well as automotive use.

In addition to the advantages listed above, there is less water condensation than with metal tanks.

[Riverman]

Here is how I installed the plastic tank in my Viper.

http://i3.photobucket.com/albums/y66/river_57/tank.jpg

[Rigaud]

Here is how I installed the plastic tank in my Viper.

Hey Jeff, that's pretty much the way mine is installed in my Rib.

[bearclaw]

Here is how I installed the plastic tank in my Viper.

http://i3.photobucket.com/albums/y66/river_57/tank.jpg

Very nice, clean installation, Jeff. Did those brackets and straps come with the tank?
Some I've looked at also have mounting tabs molded on.
Mine will have to be slightly different, since I still have a back seat.


Look for a good XLPE (Cross-linked polyethylene) Tank. They are very strong and will not deform like other plastic tanks. Stay away from LLDPE or MDPE becasue they will absorb fuel and expand.

Can you suggest a source?

Thanks,
Barry

[Bruster]

Hey Barry,
As far as fuel lines go I have always like the OMC/BRP. Treat yourself to one, they stay pliable and last. :D
B

[Riverman]

The straps are cheapo tiedowns, the brackets I made and anodized. The tank is a Moeller.

[200VEGAS]

i like markus idea about the aluminum sweating more

[flabum1017]

The thing about aluminum, you can have it built to fit. I have never see an aluminum tank that was welded and installed properly split...... most tanks that split were not built or installed right. Remember...... a proper weld is stronger than the material itself..... a hot or cold weld will fail.... a good weld will not. You would really have to beat a boat to get a tank to split unless the tank was not supported properly to begin with. The method of installation is important too.... the tank needs to be able to dry after use.... one that is foamed in or sitting in a flat surface will collect moisture and corrode fast. As for condensation inside the tank.... temperature differences occur in plastic tanks as much as they do in aluminum. The alchohol in the street pumps cause more condensation and water in the fuel now a days than the actual temp differences.

[flabum1017]

Another thing about aluminum.... I have seen tanks last 20 - 30 years in saltwater use when they are installed properly. You can assume in freshwater use, they will last longer.

Plastic.... I have seen them sag after a couple years to the point the pickup was hard against the bottom of the tank.... I have shortened a lot of pickups due to this problem.... Also, the fittings on plastic tanks are also plastic....



your choice

[jerry1865]

amen to flabum, AMEN i prefer aluminum myself because i can build the thank to fit the location. AND because i weld it with 100% integrety welds then when i am ready to instal it i first throw a psi test on it. none of my tanks need worry ....