Plastic Gas Tank In My Adventure

[langski93]

I called GW customer service about a year ago as I was replacing the deck plates and asked if it was possible that I had a plastic (polyethelene?) gas tank. I was assured all 1999 Adventure 208s had aluminum tanks. Today I was taking another real close look and either I don't know the difference or its plastic. Has anyone else encountered this? Is it possible that they were spec'd briefly and then pulled from production? Any theories? Did I get the new guy in customer service?

TL

 

[enfish]

Not sure if I can answer your question, but our 1995 208 originally had an aluminum tank. In 1998, the hull was replaced under warranty because it delaminated along one of the lifting strakes. When it came back from Grady, it had a new plastic tank. So if your 1999 model year was manufactured in 1998, maybe they were using the plastic tanks then?

 

[BobP]

I understand there is no longer a gas tank cover used on these plastic gas tank models. A buddy has one I believe is 1999 or 2000 vintage.

The distinction between aluminum and plastic is very obvious via inspection thru deck plate.

 

[seasick]

My owners manual for my 2001 208 shows a diagram of the fuel system. It identifies an aluminum tank. My tank, however, is poly. It is very easy to tell when you open an inspection plate. Even if it isn't obvious to the eye, a rap with you fingers on the tank will tell you.

 

[GWcpa]

My 1999 208 had a poly tank.

 

[R Ballou]

My 1999 208 has a metal fuel tank.

 

[BobP]

What's your concern on poly vs. aluminum?

 

[seasick]

Supposedly aluminum tanks are more prone to collect varnish from stale and old fuel sitting in them. The alcohol in E10 or E15 gas is a great solvent for varnish and was blamed for many engine failues do to the goop being disolved and feed into the engine. Poly and stainless don't seem to have the same issues (at least that is what I read).

 

[BobP]

I've never heard that before.

If non ethanol fuel was used prior in the tank for some time, when going to ethanol, the alcohol has a cleansing effect and will scrub the system and the debris that can come of it may clog filters. Wouldn't seem to matter to me if poly or metal to begin with.

Fuel not used up regularly needs to be treated to stabilize it in part to prevent varnish development. So always use a product like Stabil or Startron, or both, year round. For E10 too. It's no different than off season storage of lawnmowers. My lawnmover has a poly tank, once I didn't treat the fuel, come spring, carb was gummed up and refused to start.

Alcohol has an affinity to moisture so it sucks it up, then the alcohol and water can form and seperate from the gasoline. Not good for 2 stroke premix since the oil will stay with the gas, not the water/alcohol mix, which also stays low in tank since heavier than gasoline.

Our boats have open ventilated fuel systems, only when they become closed like our cars had for over 30 years now, will moisture in the tank with E10 no longer be an issue.

 

[seasick]

I didn't state the facts correctly. It's not that aluminum collects more varnish, it is the fact that ethanol tends to disolve the protective oxidation on aluminum and that leads to more corrosion and resultant clogging of the fuel system. The debate is at what concentration of ethanol this happens. Some research has stated that E10 doesn't break down the protective oxidation on the aluminum but E15 does.

You are correct that any tank that has collected varnishes from gas sitting will be scrubbed by ethanol.

Fiberglass is another story. Ethanol actually does disolve fiberglass. Those tanks are at risk.
Sorry for the confusion ( i must have been inhaling ethanol fumes)

 

[jehines3]

If I had to choose poly versus aluminum, I'd rather have poly. Never heard of one failing because of corrosion. jh

 

[langski93]

From the feedback, it looks like at some point both aluminum and poly were spec'd in this model. Thanks to all for taking the time to respond. It's a great site.

Langski93

 

[GT]

BobP -

Offhand question - why do boats have open ventilated fuel systems? Whats different between cars and boats that one can have closed systems and one cant?

 

[seasick]

GT:

Cars have closed fuel system because the government made it mandatory. In theory it eliminates a lot of vapors from being vented into the atmosphere. Boats don't have them because those systems are fairly complicated and would add cost to the product. There are lot more cars than boats out there but I bet there are more lawn mowers

 

[BobP]

Good question.

It' s the same reason it took 20 yrs or more to find air bags in cars, government regulation forced the auto industry profiteers to do the right thing. Viable air bag technology was available back that far.

These Gradys are high priced to begin with, what's a few hundred bucks more? Nothing complex about the system at all.

The simple system in your car requires no maintenance. Most people couldn't point out the main component under the hood if I dropped a 100 dollar bill as a bet, and all cars have the same component.

The reason it takes gov't regulation to force the boating industry to do it is because it requiree joint boat/engine development and standardization, and whoever steps up first will have to up the boat/engine price to cover development, testing, and components, making their product price less competitive than anothers who cares less, and more about profits/sales.
It's a pathetic but classic excuse seen time and time again.

If your lawnmover had a condensate generator tank of as much as 300 gals like on your Grady, it too should have the system, for both air quality your kids can breath, burn the "unburned hydrocarbons" they would have inhaled instead which effectively makes more fuel available for power, and keeping water the heck out of fuel .

 

[BobP]

As far as aluminum tanks, as you say, effectively coming up with oxide particulate in the fuel, the racor filter media covers a very large surface area and that is entirely what's it's intended to stop cold, and in my boat, there are several more particluate filters in series down stream in the engine.

And by the way, closed fuel systems benefit ethanol as well as non-ethanol fuel, more benefit for ethanol fuel, in any % formulation.