Alum fuel tank corrosion....replace? repairable? Internal pictures!

[ReefRaider]

195 gallon alum fuel tank in a Boston Whaler. Contamination clogging filters / engine. Check out the pictures and tell me what you think. Can this tank be salvaged (cleaned out, put back into use)? Or should it be replaced? Well, sure, I guess replace is the easy answer, and so be it if it is the right answer, but haven't priced a new one yet and afraid to (195 gallon!)

From what I can see it looks like some of the corners / welds are rusting then spreading that fine rusty film throughout parts of the tank. You can see where the port engine supply has been picking it up. Odd only that one, but I guess that's irrelevent. Thanks for your input.

 

[ReefRaider]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

More pics

 

[cribber]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

I'd find a place that rehabs gas tanks and get their opinion. It could be a simple job installing a liner and using the tank for support.

 

[NYBo]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

That looks like iron oxide a.k.a. rust, which can't be from the tank itself. Are you sure it's not varnish from old gasoline? Is the tank leaking

 

[ReefRaider]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

The cost of that tank is NOT going to be easy to swallow so I would absolutely try to salvage it. Have you looked into a product called "Por-15"?

Yeah, I saw it while searching. Might work for exterior projects, but haven't figured out how it could / would work internally. Know anybody that can fit inside a 2" sending unit hole?!

OK, I know, but don't really want to cut access holes, and would have to do 3 to get past the baffles. All I can think of is to "clean" it, but has the damage been done? Would it continue to rust without a coating of that or something else?

 

[tswiczko]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

195 gallon alum fuel tank in a Boston Whaler. Contamination clogging filters / engine. Check out the pictures and tell me what you think. Can this tank be salvaged (cleaned out, put back into use)? Or should it be replaced? Well, sure, I guess replace is the easy answer, and so be it if it is the right answer, but haven't priced a new one yet and afraid to (195 gallon!)

From what I can see it looks like some of the corners / welds are rusting then spreading that fine rusty film throughout parts of the tank. You can see where the port engine supply has been picking it up. Odd only that one, but I guess that's irrelevent. Thanks for your input.

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If the tank is aluminum then the tank is not rusting. The orange stuff is is a contaminant in the tank which can probably be cleaned out.

But without knowing what it actually is I can't help you, other than telling you look for a company that cleans tanks.

 

[ReefRaider]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

That looks like iron oxide a.k.a. rust, which can't be from the tank itself. Are you sure it's not varnish from old gasoline? Is the tank leaking

Tank is not leaking. Sure looks like the aluminum is rusting, which I understand is possible. This has been an issue for a few years, tired of dealing with the problems it creates. I believe it is an early victim of ethanol. It sat for awhile, so my theory is that the water separated from the fuel, which I understand can happen with ethanol, thus starting the corrosion process. I've tried running it through filters with fresh non ethanol fuel, stabilizers, etc. but it just won't go away. Time for a permanent fix, just exploring ideas to see if theres anything to do other than change the tank.

 

[Gary H NC]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

I know the POR-15 does work well.I have used it in several tanks.
They way i cleaned them was with acetone,turning the tank and sloshing it around until the varnish from the fuel was washed off.
Empty,let dray and air out then use the POR-15.

It has worked well in many old motorcycle tanks too.

 

[1fishbone]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

That doesn't look like rust or corrosion from an aluminum tank.
You sure it's not stainless? Stainless can rust around welds and spread it around.

I think you're also right about scale/rust from water in the fuel.
Rust can come from the fuel station too.

A good tank cleaning can fix that!
Look into a truck repair or truck parts store, they may do it or know of someone.
If you're from Newport RI, look for Pioneer parts in Seekonk Ma.

Then get a better filter system!

 

[NYBo]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

Sure looks like the aluminum is rusting, which I understand is possible.

Aluminum oxide is white, so there is something else going on here. POR-15 is great stuff, but it is for ferrous metals, not aluminum.

Try some acetone to see if the red stuff washes off.

 

[fishrdan]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

Looks like sludge/gunk from old fuel to me, I'd clean it out, or find someone who can clean it out for you. The problem will be getting into all the nooks and crannies to get that stuff off the tank, well then getting all the residue out of the tank. I'm not sure what would break that stuff down, though it sounds like Gary used acetone.

BTW, don't use a vacuum to suck anything out of the tank... (been discussed here before) fuel vapors + electric motor could = BOOM

 

[wire2]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

I don't see actual "rust" in any of those pictures. I see a brown stain in several places.
My first inclination on getting it totally clean is dry ice blasting.
That stain is coming from somewhere else. Is the filler tube made of steel?

 

[Fisherball]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

Aluminum itself does not rust. Rust is ferrous oxide, ferrous being iron. Unless there is an aluminum/iron alloy, which I have never heard of.

 

[Ironpig]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

I'm a welding inspector and that is not rust. I would agree that there may be other parts of the fuel system that are rusting and collecting in those spots but the aluminum, other than a little pitting in the one photo looks fairly decent. Judging by the way the staining is sitting on the metal it may be varnish or some kind of sludge. Aluminum won't rust but oxidize and turn whitish grey.

 

[foodfisher]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

I have used and it does work, one gallon pure acetone and one gallon pure xolene/xylene mixed in a two gallon can. Add 5 oz. per 10 gal. gasolene/diesel. Will clean up and improve performance thus adding longevity to your engine/s.

 

[ReefRaider]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

OK, thanks everyone. I may have confused "rust" with "corrosion", but in any case I am hearing that the integrity of the tank should be fine and I certainly will head in the direction of figuring out how to clean and not replace. I just had heard that aluminum tanks will (can) fail (corrode), and I thought maybe this was one due to moisture.

 

[Cannondale]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

Aluminum itself does not rust. Rust is ferrous oxide, ferrous being iron. Unless there is an aluminum/iron alloy, which I have never heard of.

There isn't an aluminum/iron alloy, so that's why you've never heard of it.

Aluminum used in marine applications tends to be either 5000 series, an alloy of aluminum and magnesium, or 6000 series, an alloy of aluminum, magnesium, and silicon.

The only other elements used in aluminum alloys that I'm familiar with are copper, zinc, manganese, scandium, and lithium.


Interestingly, as we're talking about aluminum oxide.....the thin layer of al oxide that forms naturally on bare aluminum is said to have the hardness equivalent of a sapphire, which is easy to understand since the most common naturally occurring aluminum oxide crystal is corundum, and sapphires and rubies are gem quality forms of corundum.

 

[64osby]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

You may want to contact the factory, send them the pics, ask what is this, whats the tank made of, and let them respond.

If you have enough access, you might try a rag or scrubby on a stick w/ gas or carb cleaner and see if the stuff wipes off, just to see if it would come off easy or not. It doesn't look like all the welds have the problem.

Good luck

 

[Home Cookin']

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

I agree that b/c it's a Boston Whaler, start with the company. They should be concerned. They will also verify whether it's SS or aluminum, which is essential to know if you are going to paint it or whatever.

Another reason I doubt the tank is rusting is that gasoline doesn't cause rust. but water in it could--such as from phase seperation caused by ethanol. So once you get straight, keep your tank full and fuel treated, maintain your filters, and turn it over every couple of months (not the boat, the gas; i.e. use your gas and replace).

I think that once you get it cleaned out (carb cleaner and a stick on a rag), and then maintain your fuel, you should do OK. Most I'd coat it with is OB oil; I'd be afraid that whatever you put in there, would be dissolved by the fuel and its additives.

 

[PKomrowski]

Re: Alum fuel tank corrosion....replace? repairable? Internal pictures!

All the posters that say aluminum dose not rust are correct, it corrodes, and that can cause pitting. Aluminum weld will not nor can not rust, if you heard of 1 aluminum tank going bad, you will have heard of 1000 steel tanks going bad, they work great, so long as you dont mix disimiler metals with it. Then you get galvanic corrosion, and corrosion eats through the metal in extreem cases, but most of the time corrosion on aluminum is self limiteing, once it oxidizes it seals its self and the oxidation stops. You need to realy check to see if those are not Stainless, they look stainless, and what the welds are doing looks very common to what can happen to stainless welds if the right rod is not used, (im a welder ) and sometime even if the right rod is used and the condions are right. Stainless comes in may typs, and they all will rust in the right condidions, some much less than others. But in welding one of the biggest concers is rust after the weld if the wrong stuff is used. I have seen it 100 times. I see no normal "whitening" of the metal that I should see if it were aluminum, not a drop, but everything I see looks like Stainless Steel. And by the way you can not always check stainless steel with a magnet, sometime depending on the type, they will not stick.