Rust inside the tank

[Winder]

Got a deal on an SV for the wife that had been stood for a while. It's all working and running now but there is a lot of rust around the filler cap and as far as I can see into the tank. The priming of the fuel pump doesn't sound right when the ignition is turned on and when the ignition is turned off there is a grumble from the fuel pump too.
Haven't pulled the fuel pump out yet but I imagine when I do the inside of the tank will be very rusty.
Can people with experience in removing rust from a fuel tank please tell me which method they used and if it was sucessful or not? Also if the process was quick and easy or time consuming and a PITA?
Cheers
Mark

[maviczap]

Ball bearings, count them in & count them out. Other people use gravel I think?

But you've got to be careful & not damage the drain pipe, if pointy's have one.

Several other methods here

https://www.youtube.com/results?sear...tank+derusting

[Winder]

Cheers. I know all/most of the options available but really just wanting to hear from anyone who has actually done it.
So far I'm leaning towards metal rescue rust remover as it looks simple, it's only one step so no re-lining the tank etc. Vinegar and other acids looks like an idea too.

[Bibio]

i done my brothers duke and it was in a right state. drain tank. remove all taps, caps and pumps. let it dry out and get a flexible hoover crevice tool and suck most of the rust out. if you can get your hand into the inside of the tank then use a small wire brush to clean the rest of the rust. get some phosphoric acid (strongest you can get) and paint the inside of the tank with it then wire brush again then acid again.

[Winder]

Was reliving of the tank required afterwards to prevent flash rusting? I here metal treated with acid will do this.
Still if it worked well for you it may work well for me.
Cheers

[Bibio]

nope. using phosphoric acid will kill the rust. it's people who do half arsed jobs and expect miracles who get rusty tanks afterwords that complain. remember what you are putting in the tank afterwords... ermm petrol, petrol does not cause things to rust its the water that can come with the petrol that causes the rust.

dont use sealants they also lock rust in as well as keep it out so end up rusting to the front surface, if a tank is that far gone then just get another tank. only classic tanks that are hard to get need serious work and usually involve getting the plasma cutter out.

[Winder]

Thanks.
Not after a miracle and not planning on doing a half arsed job. The tank got rusty in the first place and I'm sure the previous owner was also only putting ermm petrol in the tank. I don't want to use a sealent or anything else that isn't required so that's good news if I don't need it.
Any other methods used people?

I've done four rusty tank jobs. Removing the rust will require acid treatment, but first, clean it with acetone and some sort of mechanical aid, like a hand full of steel nuts. Whatever you put in will be hard to get back out, if it's steel, you can use a magnet. Some of them will still be hard to get out.
After acid treatment, (phosphoric is recommended, but muriatic is faster) you will have bare steel, which will rust, so you will have to treat it. Your tank rusted initially because the factory protective coating broke down, permitting water (that you simply can't keep totally out of your tank) to cause rust.

I've found POR-15 to be very good, and its made to work over flash rust, which you will have.

Anything you do will be a big PITA, with good chances of messing up the outside finish.
Any sealant you install will be a big PITA to install properly, that is with full coverage, but without having puddled areas where the too thick sealant has potential to cause future problems.

Acetone will ruin the paint. Acid will ruin the paint. The crud and rust will be difficult to remove. The sealant will be difficult to install properly and hard to get off the paint. You can easily scratch the paint while doing the work, and both acetone and acid will get under any masking/protective covering you put over the outside, making things worse, since you won't know it's eating the paint until it already has.

[Winder]

Cheers for that mate. Sounds like a big bag of ass. Still, a new tank costs a fortune and a used one in grey is impossible to find so looks like I'll be doing it anyway.

Agree with wideguy, the por-15 kit works well just make sure to follow the instruction to the letter and don't try and rush it.