Diesel tank; static for 18 months

[jasavo]

The boat I have just acquired has been laid up ashore for the last 18 months. The stainless steel diesel tank is full. It is also relatively easy to access and remove. Therefore would it be worth the hassle to drain the tank and remove it and then clean it? If so what is the best way to clean the tank?


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[Plum]

Either drain off or pump out a few lites of diesel from the BOTOM of the tank and inspect for sludge and water. If none, then do nothing, just make sure you have a good filter and water separater system in the fuel line.

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[Benbow]

Stainless steel is not the ideal material for a fuel tank and there is likely to be corrosion and gunk at the bottom. If it was my boat I would drain it and remove it for inspection. After its out you can have it steam-cleaned, or you can do it yourself just put in detergent and very hot water many times. Finally get it completely dry before putting it back. I have done this to a 20 litre SS tank by putting on the gas cooker and carefully heating it up. Care is needed because there may be an explosion if
a) there was any fuel left
b) the wife sees you.

However I have survived this several times.
When its done, either put it back in use immediately or spray inside with WD40 or similar to prevent corrosion - after its cool of course !

(I am assuming there is an inspection hole of reasonable size to allow you to look in and ensure that it is clean and dry. If not get one cut.)


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[Freebee]

I would go for the" if it aint broke dont fix it approach"! Is there a drain in the bottom of the tank if so try and get a fuel sample from the bottom, if its clear and bright dont touch it, if its water or watery then drain it it until the fuel runs clear, if you get brackish fuel or slime or a jelly like sludge, be prepared to remove and clean. Its all a matter of housekeeping.
But I would recommend changing all fuel filters as a matter of course.

Despite whats posted here IMHO stainless steel if its the right grade, is good for a fuel tank, its only the poorer grades that will corrode.

If you have to clean the tank and it has some means of accesing the inside I would recommend no more than wiping out with a clean rag.

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[Benbow]

OK, I would agree that if you can be _sure_ it aint broke then don't fix it. The problem is that sampling diesel from a tank that has not moved for months will not tell you much. I have seen a stainless tank with dozens of 'islands' of corrosion all over the bottom, each a focus of crud and bits that when churned-up would cause problems, yet a sample from the drain showed nothing.

If you can really look inside with a torch and see the bottom clearly, and if it looks clean, and if diesel is coming out clean then I agree that you are probably safe.

If you can't, I would clean it.

(True good quality ss, properly welded using the right materials, can make a very good diesel tank, the trouble is that in a 2nd-hand boat you often don't know)


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