Rust in petrol tank

[Mattblack]

I've just starting pulling apart a motorbike that has been sitting for about 10 years.
1st thing I'm doing is replacing all the fluids and I'm starting with the tank. Of course it's full of sludge and there is also rust present when I run my finger inside. Anyone know how to clean it out the neutralise the rust?

[Gultch78]

Methylated spirits to clean it and break up the water as for rust proofing fill it up with vinegar let it sit for 2 days then empty rinse with metho again and fill with an oily petrochemical straight away
Note
I have never tried this with an enclosed vessel like a fuel tank but same principals apply
Note
Do not leave tank unprotected after the vinegar/citric/ascetic acid step as the steel will start rusting in open air

[Texas]

Wire brush & kill rust ?? (I don't really know).
When I had rust in the pipes, it needed an operation (umbrella was mentioned)

[Bugatti]

I remember seeing a Car Reno show on Channel 44. They did an acid fill for a fair bit of time. And from memory, placed small gravel in the tank with the acid. Then shook the tank with the acid & gravel in it to loosen/sand the gunk and rust from the inside.

Then after washing it well, a neutralising agent in the tank, which they swished it around every half hour for a fair bit of time.

I can't remember the acid or the neutralising agent , , , , but I do remember it had to be for petrol tanks.

That's the best this memory can do. Hope it helps Mr Black

Cheers, Bugatti

[Mattblack]

Thanks Gents...did the metho rinse yesterday and it got rid of all the sludge. Did some googling and it backs up what you guys suggested....gravel and apple cider vinegar will be going in tonight.
Lesson learnt, keep the tank full of fuel (with stabiliser) when in storage!

[Gultch78]

Just vinegar is all that is needed filled to the top and left alone 24 hrs i wouldnt add dirt to the fuel system maybe pressure wash beforehand

[Gultch78]

If this was an industrial job we would use circulated citric acid and then neutralize with amonia to bring the ph down which leaves a nice protective coating from the air

[Mattblack]

If this was an industrial job we would use circulated citric acid and then neutralize with amonia to bring the ph down which leaves a nice protective coating from the air

Thanks Mate....will fuel stabiliser stop the rust building up again?

[Gultch78]

Probably not because of porous inner wall of fuel tank (fuel flashes off leaving exposed to oxygen )
if you keep tank full when not in use should be fine and buy a clear inline fuel filter and add it after tank tap to keep an eye on sediment build up

[Mattblack]

Here’s how it went....

This is what came out after the metho rinse

after the vinegar rinse (sludge)