TheSamba.com :: View topic - gas tank

Sun Feb 05, 2023 3:22 pm

Was there ever a after market plastic fuel tank made? Or do they need to be steel because of their proximity to the engine?

Sun Feb 05, 2023 3:37 pm

I've never heard of or seen a plastic tank for any VW, I don't think location has anything to do with it.

Sun Feb 05, 2023 3:54 pm

My 1982 CJ7 had an optional factory 20 gallon tank with a steel liner instead of the factory 14 gallon steel one. One morning I came out and smelled gasoline in the garage. Thank God my water heater was electric and in another location. The tank broke along a top seam where the sender went into it. Fortunately they had not gone NLA yet. I would never want another car with a plastic tank for fuel. Go buy a red plastic approved fuel tank and leave it in the sun for an hour. The heat will swell and permanently distort it. Steel is the only way to go. If yours needs cleaning find a shop that does it. If it is rusted thru find a good used one if you have FI. The repops lack the proper baffles for FI

Sun Feb 05, 2023 4:17 pm

If your talking plastic fuel cell that's something different. They have been proven in race vehicle for decades.

Sun Feb 05, 2023 6:32 pm

bsairhead wrote: If your talking plastic fuel cell that's something different. They have been proven in race vehicle for decades. yes - fuel cells can be steel, plastics or aluminum. They are full of absorbents that keep the fuel from just gushing out. Most are going to be aluminum. The smaller ones for drag racing can be plastic.

Sun Feb 05, 2023 6:42 pm

I was just thinking how rusty these things get. If a plastic tank was an option I was going to check them out. The hmmwv’s all have plastic fuel tanks. And they’re meant to be abused. The tanks are exposed underneath as well. I figured if those fuel tanks could hold up, the vw’s may have an option.

Sun Feb 05, 2023 6:45 pm

used or inferior re-pops are your choices for our bays.

Sun Feb 05, 2023 6:50 pm

There’s an expensive nylon reinforced plastic made by Corning, that makes great fuel tanks for Volvo.

Sun Feb 05, 2023 7:06 pm

Take it to a radiator shop, they will clean it out with muriatic acid and then coat it with red kote rubber sealant

Sun Feb 05, 2023 9:56 pm

SGKent wrote: I would never want another car with a plastic tank for fuel.

better bring your MDX to the crusher then

Sun Feb 05, 2023 10:43 pm

steel

Sun Feb 05, 2023 10:43 pm

skills@eurocarsplus wrote: SGKent wrote: I would never want another car with a plastic tank for fuel.
better bring your MDX to the crusher then
It is steel or aluminum. I am up in there every time I pull the spare down. I also mounted a 3500 lb hitch. There was a recall on a brief number of 2015 MDX with STEEL fuel tanks where the welds were not proper.

Mon Feb 06, 2023 11:01 am

My ancient Dodge truck has a plastic tank. The Truck itself is a 1972 which had a tank in the cab, but when the cab was replaced because of rotten floors I got rid of the in-cab tank and hung a plastic tank from a circa 1990 truck under the bed. This tank is pretty tough and as of yet is not showing signs of decay.

Mon Feb 06, 2023 12:33 pm

I read somewhere, that there is a class of impact for which a steel fuel tank will burst along the welds while a polypropylene tank distorts but retains its shape.

Above that level, both tanks burst but then your vehicle has probably changed shape badly enough that bits of its structure are puncturing the tank.

Your fuel tank shouldnt be out in bright sunlight unles the bed of your truck has rusted out ..

Mon Feb 06, 2023 3:42 pm

There are actually very few cars made with metal fuel tanks anymore.

The few that are.....the question is why,?

The early plastic automobile gas tanks 1980s into 90's-ish.....were made similar to small engine plastic tanks....meaning single layer and with polyethylene resins that are pretty much no longer used. The resins those were obsolete by the 1990s.

Automotive plastic tanks are multi-layer with vapor barriers molded in and are a blend of Uv resistant crosslinked HDPE and polypropylene. Last I heard there are actually five main plastics that go into fuel tanks for automobiles.

They are also spectacularly reliable.

If someone made a DOT certified plastic fuel tank for a bus.....you should buy it. Ray

Mon Feb 06, 2023 3:53 pm

raygreenwood wrote: There are actually very few cars made with metal fuel tanks anymore.

The few that are.....the question is why,?

The early plastic automobile gas tanks 1980s into 90's-ish.....were made similar to small engine plastic tanks....meaning single layer and with polyethylene resins that are pretty much no longer used. The resins those were obsolete by the 1990s.

Automotive plastic tanks are multi-layer with vapor barriers molded in and are a blend of Uv resistant crosslinked HDPE and polypropylene. Last I heard there are actually five main plastics that go into fuel tanks for automobiles.

They are also spectacularly reliable.

If someone made a DOT certified plastic fuel tank for a bus.....you should buy it. Ray maybe you should get one of your clients to make one. Would it be more dangerous in a bus fire?

Mon Feb 06, 2023 4:38 pm

I’m not an expert but my guess would be that it would melt, catch the gas on fire, instead of overheating and exploding.

Mon Feb 06, 2023 4:48 pm

SGKent wrote: raygreenwood wrote: There are actually very few cars made with metal fuel tanks anymore.

The few that are.....the question is why,?

The early plastic automobile gas tanks 1980s into 90's-ish.....were made similar to small engine plastic tanks....meaning single layer and with polyethylene resins that are pretty much no longer used. The resins those were obsolete by the 1990s.

Automotive plastic tanks are multi-layer with vapor barriers molded in and are a blend of Uv resistant crosslinked HDPE and polypropylene. Last I heard there are actually five main plastics that go into fuel tanks for automobiles.

They are also spectacularly reliable.

If someone made a DOT certified plastic fuel tank for a bus.....you should buy it. Ray maybe you should get one of your clients to make one. Would it be more dangerous in a bus fire?

Oh...forgot to mention....the early single layer materials were WHY the early plastic tanks had cracking issues like you found with yours...especially right near but not on....the plastic weld line.
From the people I have talked to and articles they pointed me to.....the early material issue was a combination of just a few 10ths of a percent of incorrect plastic density and wrong plastic formulation (to much crystallization or....being a nearly amorphous plastic).....but coupled with a non multi-layer design.

None of this is an issue anymore. The only issues commonly seen are when it's just bad car design (ergonomics) and the tank impinges or rubs on hard surfaces and gets a hole in it. But that's a lot of rubbing.

As for safety.....the plastic tank is actually safer. The plastic tank is actually harder to puncture because it can deform and has a rebound memory. The whole point is that if its not punctured and the car catches fire.....the plastic tank will melt and release pressure and while that will release fuel and bur ....it has little to no risk of pressurizing while heat and causing an explosion. Ray

Mon Feb 06, 2023 6:02 pm

only in the VW Bay forum is the defense of a modern fuel tank that, what happens when it(bus) catches on fire..

how about you all address just WHY you catch them on fire in the 1st place..
but indeed changing fuel lines, and wire tying fuel fittings (T1) is still foreign concepts to most (non samba edumacated) owners.

fwiw.. Syncro Vanagons have had plastic tanks since 1985. it's located up over the transaxle and well haven't heard them any more an issue than any other location..

buncha hippies and codgers... poking strange things with a stick... Ooohh... ahhhhh... SMFH

Mon Feb 06, 2023 7:06 pm

DuPont blends nylon with HDPE under trademark SELAR for fuel tanks

Honda, Mitsubishi, Kia, Toyota, Volvo and others