plastic gas tank ?

[russell1]

how long does a plastic gas last for?

[RickK]

Hey Russ, I don't know if any of us will know that answer. Maybe it's best to "google" that and let us know what you find out. Better than getting frustrated that no one is answering.

[JimCt]

Unless the plastic, which I assume is polyethylene, is abraided or exposed to a lot of UV, it should be good for many years.  Biggest problem you may find if it's an old tank is the E10 (10% ethanol) fuel.  The E10 will tend to loosen any old gas crud & varnish in the tank.  When/if that happens you will have to  keep changing filters for a while until the debris is flushed out of the system.  You can thank Washington for that inconvenience.

[russell1]

I tried to google it But kept finding the same answers,the ones I have now are from 1991'..I wanted to use one for a third tank under the casting deck.I planned on getting new one's for the new honda but wanted to use the third for the kicker.I'm just curious if anybody has had a problem with them or if somebody has a plastic tank how old is it.

[JimCt]

I wouldn't worry about a poly tank.  When you install it make sure it is well secured so it doesn't chafe with the motion of the boat.

[GoneFission]

I believe that 10,000 years from now, when future archeologists are digging to look up ancient history from the 20th and 21st centuries, they will find - you guessed it - plastic - probably including your gas tank and some of our boats.  Some of this stuff is next to impossible to naturally degrade, and the only way to remove it from the Earth is incineration...  

See ya in 10,000...

[Fishhead]

how long does a plastic gas last for?

Russell,My dads boat is a Osprey Pilothouse 24 ft.It has a 150 gal. tank, poly under cabin that can only be accessed by removing the whole inner liner,pilothouse and all.They dont have the issues alum. tanks do. IMHO alum. tanks fail early do to bad  installation

[russell1]

thanks for the input,I couldnt find anything on the internet about plastic tanks failing due to breakdown,I did read of somebody putting a couple of screws through one...I'd still like to hear of any others

[ddd222]

russ, i have also heard of the ethanol fuel reeking havoc on plastic tanks. 2 of my bosses boats are getting new tanks this winter and he said plastic is a non-option w/ new crappy gas. Can't quote any particular instance of failure, but given my experience w/ most of the moving parts of the outboards and inboards we run on his boats, scheduled maintenance and replacement on many parts on motors are cut by 30-40%. From whats been explained to me the ethanol gas makes fuel lines, gaskets etc. swell and deteriorate faster. So logically it would seem to me to shorten the life of a plastic tank. Actually now that i think of it a friend is having his tank cut from the deck on his 01' pursuit, will update if ethanol gas played a role

[russell1]

I think no matter which way you go with the gas tanks there's going to be trouble thats something to think about with the extended warrenty options on motors..I know of a couple of marina's around hear that have less ethonal in the gas then a car gas station but of course your paying more.Also the gas only stays good without a additive for 30 days which I'm sure is causing alot of problems with the fuel systems..How about a wood gas tank (just kidding)..who ever comes up with the solution for these problems is going to be rich

[ddd222]

russ, i'm curious, did u already buy the plastic tank? Seems like your waiting for someone to tell u it's ok to use plastic? The response seems to be a united front on the ethanol, plastic tank combo. If your are opening and exposing the deck, stringers, do it right even it's more expensive. If the tank fails or leaks sooner u could have alot more problems than replacement and inconveniance, god forbid catastrophic. Just a thought, lookin out for ya

[russell1]

no i didnt purchase new tanks yet.but I do have the 2 older tanks from 1991,I'm not useing old tanks with my new honda.I'm going to use one of the tanks under the front casting deck probaly for a freshwater wash down or fuel for my kicker when trolling.But the tanks on my boat where under the console so getting them out would be easy,I've been talking to a local gas tank builder and I'm probaly going to go with a aluminum custom made 65 gal wrapped in fiberglass to fit back under the console..and yes there totaly secure from electric wires..the deck and stringers are totaly redone already I'm keeping the boat the way it was I didnt feel like moving stringers or hacking them like most people do.

[JimCt]

Good plan.

[russell1]

There are literally thousands of aluminum fuel tanks in boats across this country that are time bombs waiting to go off ... and yours might be next. Consider that just two ounces of gasoline, or about as much gin as you'd put in your martini, has the explosive power of several sticks of dynamite. It is more than enough to turn your boat into matchsticks, along with anyone unlucky enough to be in it.

The fact is that aluminum (including the so-called "marine alloys") is a highly anodic material and, in contact with most other metals, it can deteriorate rapidly. Aluminum quickly corrodes when in contact with water and, in particular, salt water. Aluminum is subject to fatigue when it endures continual flexing, such as when the fuel surges around as the boat pounds across a choppy harbor. And then, of course, there is the problem of joints which rely heavily on the experience, or inexperience, of the welder.

So why do most boat manufacturers use aluminum tanks? The answer is brutally simple: they're cheap. A far better tank is one of the many polyethylene tanks available, but at a higher cost. It is a case of keeping down the price and not worrying about the consequences a few years down the line.

A corollary to this callous disregard by many boat builders is that they install the aluminum fuel tanks in ways that almost insure that there will be problems. Many builders place the fuel tank in the boat and then seal the cockpit on top of it without leaving a way to inspect or replace the tank.

This means that if you do find a leak in your tank, you have to literally destroy the cockpit floor of your boat to remove the tank. A few boat manufacturers who have a conscience and basic good sense install a removable panel in the cockpit floor so that owners can regularly inspect the fuel tank thoroughly. On a wood floor, that might mean a piece of plywood above the tank that is screwed into place. On boats with molded cockpit floors, it would be a fiberglass lid that is probably both screwed and siliconed in place.

Compounding the problem, some manufacturers use foam to help secure the tanks in place. This method is illegal, of course, because federal regulations strictly prohibit encasing a fuel tank in a way that allows water to collect on or around the tank (33 CFR Part 183, Subpart J, Article 183.552, if you're interested).

Which brings up another problem. Both the U.S. Coast Guard and National Marine Manufacturers Association standards regarding fuel tanks and their installation are almost laughably vague and inept. If you think that little metal plaque attesting that your boat meets USCG and NMMA approvals is an assurance of quality construction or safety, think again. A far better standard, which should be adopted by both organizations, is the National Fire Protection Association (NFPA) number 302, which are comprehensive standards for pleasure boats.

So what can you do to protect your boat and your family? First of all, inspect your tank regularly. No, this doesn't mean just looking at the top of the tank through the 8-inch inspection port provided over the gas fittings. I mean you look — and touch — every square inch of the tank: top, sides and particularly the bottom, which is prone to corrosion from bilge water. If the tank is held in place by straps, loosen them and look under the straps for corrosion.

If your boat is one that has an uninspectable fuel tank, you're in trouble. You might present the boat back to the dealer and ask him to modify the cockpit floor — at his cost — to allow safety inspections.

But your boat is only a couple of years old, so how could it be dangerous? When a consumer boating magazine investigated fuel tank failures several years ago, they found that the age of many leaky tanks was less than 4 years old.

just a little info I found

[John Jones]

http://www.yachtsurvey.com/fueltank.htm